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Introduction: Many adults who smoke cigarettes report trying e-cigarettes to quit smoking. Understanding the use of e-cigarettes for smoking cessation and the type of support that adults desire when trying to quit smoking is important for supporting cessation attempts and maximizing smoking abstinence., Methods: In summer 2021, an online survey of 857 adults who reported a history of regular cigarette smoking and endorsed using e-cigarettes in a recent smoking cessation attempt was conducted. Survey items assessed reasons for using e-cigarettes to quit smoking, what was helpful about e-cigarettes, and what information participants desired when using e-cigarettes to quit smoking., Results: Common reasons for using e-cigarettes to quit smoking included beliefs that vaping would be helpful for quitting (53.6%), vaping is safer than smoking (50.5%), and favorable comparisons relative to other nicotine replacement treatment (NRT) like nicotine patches and gum (24.7%). 23.8% selected e-cigarettes because they were cheaper than other smoking cessation aids. 89% of participants reported still smoking cigarettes at the time of survey. The most common information people wanted when quitting was advice on how to gradually reduce nicotine over time to become nicotine-free (46.3%), how different vaping devices work (39.7%), and what nicotine concentration to start with (37.7%)., Conclusions: Findings identified common beliefs about e-cigarettes as a smoking cessation aid and how they compare to other treatments including NRT. Understanding factors that support cessation are critical especially due to high relapse rates. Results may help to inform support programs, especially for individuals who are interested in using e-cigarettes to quit smoking., Implications: Despite greater reporting, there is a limited understanding of e-cigarette use for quitting among those who smoke cigarettes.Our study highlights the reasons for using e-cigarettes among those who have recently tried e-cigarettes for quitting smoking, and the components of e-cigarette that were helpful.We also examined the desired support in a program designed to use e-cigarettes for quitting smoking. Majority of participants who attempted to quit smoking using an e-cigarette relapsed to smoking, indicating the gap in cessation support that can be filled with greater understanding of the desired support., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Introduction: Nicotine withdrawal is a well-established construct that prompts continued nicotine product use and contributes to failed cessation efforts. Despite ongoing public health concerns about nicotine e-cigarette use in adolescents and young adults (AYAs), no psychometrically-sound measure of nicotine e-cigarette withdrawal exists for this population., Methods: A mixed methods approach comprising a literature review to identify existing nicotine withdrawal items; subject matter expert feedback on existing items and novel item generation; cognitive interviews assessing the measure's instructions, items, and response options; and a large quantitative validation survey (N = 997) was employed to develop the novel retrospective measure of nicotine e-cigarette withdrawal., Results: A 25-item solution comprising four subscales - Negative Affect, Negative Physical Symptoms, Craving, and Appetite/Food - and an Overall Withdrawal score was supported. Internal reliability was excellent (mean alpha = 0.91), and scalar measurement invariance was reached for all subgroups tested (e.g., sex, age, exclusive e-cigarette use versus dual tobacco product use, daily versus non-daily nicotine vaping). Overall Withdrawal and its subscales evidenced concurrent validity with time to first vape in the morning, e-cigarette dependence, and previous vaping cessation attempts, although not each subscale was associated with each outcome. Importantly, cross-sectional incremental validity analyses indicated that retrospective withdrawal accounted for variance in each outcome above and beyond e-cigarette dependence., Conclusions: The novel retrospective AYA Nicotine E-cigarette Withdrawal Scale (AYA NEWS) evidenced strong psychometric properties for use in this population. Future research can determine whether the AYA NEWS can be used to assess acute e-cigarette nicotine withdrawal., Implications: While e-cigarette use remains the most prevalent form of nicotine product use among adolescents and young adults, there are limited options for psychometrically-sound measures of e-cigarette-related constructs in this population. Withdrawal from nicotine is associated with failed cessation attempts and continued use of nicotine-containing products, making it a critical construct within tobacco-related research. This study outlines the development and preliminary psychometric evaluation of a novel, retrospective measure of nicotine e-cigarette withdrawal. Study findings support using the Adolescent and Young Adult Nicotine E-cigarette Withdrawal Scale (AYA NEWS) to assess retrospective withdrawal from nicotine e-cigarettes in young people., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Introduction: Contingency management (CM) interventions deliver monetary reinforcers contingent upon biochemically verified abstinence from smoking. CM has been found to be effective, however, individual participant, analyses are warranted to further elucidate how individual-level behavior patterns vary during the intervention period, both within and across treatment groups., Aims and Methods: This is a secondary analysis of a randomized controlled pilot trial of presurgical cancer patients who smoke (RCT N = 40). All participants were current everyday smokers and were enrolled in cessation counseling, offered nicotine replacement therapy, and submitted breath CO testing 3 times per week for 2-5 weeks. Participants randomized to CM received monetary reinforcers for breath CO ≤6 ppm on an escalating schedule of reinforcement with a reset for positive samples. Sufficient breath CO data exist for 28 participants (CM = 14; monitoring only [MO] = 14). Effect size was calculated for differences in negative CO tests. Time to first negative test was tested using survival analysis. Fisher's exact test was used to assess relapse., Results: The CM group achieved abstinence more quickly (p < .05), had a lower percentage of positive tests (h = 0.80), and experienced fewer lapses following abstinence (p = .00). While 11 of 14 participants in the CM group achieved and sustained abstinence by their third breath test, this was only true for 2 of the 14 MO participants., Conclusions: Those in CM achieved abstinence quicker and with fewer lapses than those engaged in MO speaking to the efficacy of the schedule of financial reinforcement. This is particularly important within presurgical populations given the potential benefits to postoperative cardiovascular and wound infection risk., Implications: While the efficacy of CM as an intervention is well established, this secondary analysis provides insight into the individual behavior patterns underlying successful abstinence. Those assigned to CM were not only more likely to achieve abstinence, but did so more quickly and with fewer instances of relapse. This is of particular importance to those scheduled for surgery where achieving abstinence as early as possible impacts on the risk of postoperative complications. CM interventions may be particularly well suited for critical windows in which timely and sustained abstinence is advantageous., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Many adults who smoke cigarettes use e-cigarettes to try to quit smoking; however, some are not successful. Identifying factors that are associated with successfully quitting smoking using e-cigarettes is important for maximizing cigarette cessation., Aims and Methods: Online survey data were collected in 2021 from 857 adults in the United States who reported using e-cigarettes in a recent attempt to quit smoking. Survey items assessed patterns of e-cigarette use and device characteristics (flavors, device, and nicotine) used when trying to quit smoking. Multivariable linear regression models examined characteristics associated with the longest duration of smoking abstinence when using e-cigarettes to try to quit., Results: The average duration of smoking abstinence when using e-cigarettes during a quit attempt was 65 days (SD = 104). In the multivariable model, greater frequency of e-cigarette use when quitting and abruptly switching to e-cigarettes from cigarettes (vs. gradually reducing) were significantly associated with longer durations of abstinence (p < .001). Preference for non-tobacco (relative to tobacco) flavors and nicotine concentration were not associated with duration of abstinence, although preference for rechargeable pod and mod device types (vs. cig-a-likes) was associated with longer durations of abstinence., Conclusions: Patterns of e-cigarette use were related to abstinence duration, which may provide guidance for adults who are using e-cigarettes to quit smoking to encourage complete substitution and maximize smoking cessation. Findings indicate that non-tobacco e-cigarette flavors and nicotine strength are not related to longer durations of cessation success for adults, which may inform tobacco regulatory policies limiting these constituents to protect public health., Implications: This study provides important new information about the characteristics of e-cigarettes used during an attempt to quit smoking among adults across the United States and identifies factors associated with quitting success. Patterns of e-cigarette use were associated with longer durations of abstinence. In contrast, few e-cigarette characteristics were associated with abstinence. Although preference for some pod and mod device types was associated with longer abstinence duration compared to earlier cig-a-like devices, preference for non-tobacco (vs. tobacco) flavor and nicotine concentration were not associated with abstinence. Findings may help inform guidance for adults using e-cigarettes to quit smoking and support tobacco regulatory policies., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: As the science base around the potential benefits of a reduced-nicotine standard for cigarettes grows, information on the potential effects on adolescent smokers is a high priority. The aim of this randomized trial was to test the influence of 3-week exposure to reduced nicotine cigarettes in a sample of adolescent daily smokers., Aims and Methods: In this double-blind, two-arm, randomized controlled trial (NCT0258731), following a 1-week baseline, adolescent daily smokers not currently intending to quit (ages 15-19 years, n = 66 randomized) were urn randomized to use either very low nicotine content (VLNC; 0.4 mg/g; n = 33) or normal nicotine content (NNC, 15.8 mg/g; n = 33) research cigarettes for 3 weeks. Participants attended five study sessions at our clinical laboratory. The primary outcome was average total cigarettes smoked per day (CPD; including both study and non-study cigarettes) at week 3., Results: Stepwise regression results demonstrated that compared with NNC cigarettes (n = 31), assignment to VLNC cigarettes (n = 29), was associated with 2.4 fewer CPD on average than NNC assignment (p < .05) week 3 when controlling for covariates (p < .01, Cohen's d = 0.52 n = 60 completed all procedures). VLNC cigarettes were also associated with lower levels of craving reduction than NNC cigarettes (Questionnaire on Smoking Urges Factor 2, p < .05). No group differences were found for secondary outcomes., Conclusions: Adolescent participants assigned to VLNC use for 3 weeks smoked fewer total CPD relative to the NNC group. Overall, data suggest that a VLNC policy would reduce cigarette smoking in adolescents who smoke, but high rates of incomplete adherence suggest that youth may seek alternative sources of nicotine in this scenario., Implications: The US Food and Drug Administration may enact a reduced-nicotine product standard that would affect all commercially available cigarettes. One important population affected by this policy would be adolescents who smoke. This study, the first clinical trial of VLNC cigarettes in adolescents, demonstrates that adolescents switched to VLNC cigarettes for 3 weeks reduced their CPD relative to the normal-nicotine cigarette control group, without leading to increased respiratory symptoms or increased withdrawal. Biomarkers indicated the use of other sources of nicotine, suggesting that such a policy will need to consider approaches to assist in transitioning away from smoking., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Black communities are targeted by more cigarette advertisements than White communities and racial discrimination among Black people is related to cigarette use. However, little is known about these factors with non-cigarette tobacco product use among Black adults. Therefore, this study assessed the association of non-cigarette advertisement exposure and racial discrimination with use of non-cigarette tobacco products among Black adults., Aims and Methods: Black adults (n = 533) from The Family and Community Health Study in 2016 were asked if they had seen advertisements for e-cigarettes, snus pouches, filtered cigars, large cigars, cigarillos, dissolvable tobacco, smokeless tobacco, hookah, and tobacco pipe and if they used these in the past month. For products with the highest past month use and significant correlations with advertisement exposure, separate logistic regression models were performed that evaluated the association between advertisement exposure, racial discrimination, and non-cigarette tobacco product use while controlling for cigarette use, sex, socioeconomic status, and age., Results: Use of cigarillos, large cigars, and hookah were higher than other non-cigarette tobacco products assessed. Logistic regressions revealed that more advertisement exposure in the past month was associated with higher odds of using cigarillos, large cigars, and hookah (p < .01). More experiences of racial discrimination were associated with past month cigarillo use, but not hookah or large cigars (p < .01)., Conclusions: Non-cigarette tobacco advertisement exposure was associated with the use of non-cigarette tobacco products. Experiences of racial discrimination were associated with the most used non-cigarette tobacco product among Black adults, cigarillos., Implications: This is the first time that a specific type of cigar (ie cigarillos) has been associated with experiences of racial discrimination among Black adults. Efforts to reduce non-cigarette tobacco marketing and eradicate exposure to racial discrimination among Black adults may aid in eliminating tobacco-related health disparities., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: E-cigarettes are increasingly being marketed as containing tobacco-free nicotine (TFN). There is no data examining use of TFN e-cigarettes by young adults and how use may differ from non-TFN e-cigarettes. The current study aims to characterize young adult TFN e-cigarette use and examine differences between those who report using TFN and non-TFN e-cigarettes., Method: U.S. young adults (18-25) with lifetime e-cigarette use (n = 927) were recruited via online panels in Fall 2021 and answered questions about TFN and non-TFN e-cigarettes. Participants were categorized by lifetime TFN e-cigarette use status (yes vs. no; 34% yes). Bivariate comparisons examined differences in e-cigarette characteristics (device type, flavors, nicotine concentration) between the TFN and non-TFN groups. Binary logistic regression models examined associations between lifetime frequency of vaping (<100 vs. ≥100 times), and other tobacco product, cannabis, and/or alcohol use and lifetime TFN e-cigarette use (yes vs. no). Adjusted models include age, race/ethnicity, vaping onset age, and sex., Results: In multivariable adjusted models, lifetime TFN e-cigarette use was associated with younger age, greater lifetime vaping, and nicotine pouch use. Young adults who used TFN e-cigarettes were more likely to report fruit, mint, menthol, and beverage flavors and know their e-liquid nicotine concentration compared with those who used non-TFN e-cigarettes., Conclusion: Among young adults who have used e-cigarettes, more frequent e-cigarette use and use of nicotine pouches, which can also contain TFN, were associated with TFN e-cigarette use. Understanding behaviors and characteristics of those using TFN e-cigarettes is critical to regulation of TFN containing products., Implications: This study characterizes young adults who report experience with tobacco free nicotine (TFN) e-cigarettes and compares them to those who have not used TFN e-cigarettes. Young adults with more frequent e-cigarette use and use of nicotine pouches are more likely to report TFN e-cigarette use., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Flavored electronic nicotine delivery systems (ENDS) and tobacco products are associated with the initiation and progression of tobacco use. With recent restrictions around flavored products, it is critical to measure both the product and the flavor being used. The Tobacco Centers of Regulatory Science (TCORS) Flavored Tobacco Products Measurement Subcommittee (FTPMS) was established to develop core measures to assess flavored tobacco and ENDS product usage, facilitate data harmonization, replicability, and comparisons across studies., Aims and Methods: The FTPMS used a mixed-method approach to inform the development of recommended measures (first use, current use, reasons for use) to assess tobacco and ENDS product flavors. This included reviewing existing surveys, identifying priority areas, developing new measures, cognitive testing, and finalization of recommended measures., Results: Recommended measures were selected from national surveys (e.g. PATH study) and survey items used in TCORS studies to evaluate first use, current use, and reasons for use of tobacco and ENDS products. Response options were expanded for questions about specific flavors and adapted to allow for assessments relevant to recent federal policies. Supplemental measures were developed for researchers conducting more in-depth research around flavored products., Conclusions: Using an expert consensus process supplemented with cognitive testing, the FTPMS developed recommendations for core and supplemental measures for flavored tobacco and ENDS products. Harmonizing data on these factors for flavored tobacco and ENDS products are critical for researchers and may provide actionable evidence to federal, state, and local regulators and policymakers, as well as support evaluations of policies restricting flavors in these products., Implications: The development of core measures to assess first use, current use, and reasons for use of flavored tobacco and ENDS products will facilitate data harmonization, replicability, and comparisons across studies conducted in different samples or across communities with varying levels of regulation for these products. Use of these standardized measures will allow for a greater understanding of the role of flavors and helps to build a more robust evidence base to inform regulatory decisions to reduce tobacco and ENDS use at the population level., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.)

Background: Nicotine pouches containing synthetic nicotine or tobacco-derived nicotine (TDN) are available in the United States. Synthetic nicotine pouches are often marketed as "tobacco-free nicotine" (TFN), which may alter risk perceptions and product appeal. This study examined young adults' perceptions of TFN versus TDN pouches and the associations between product perceptions and TFN pouch awareness, susceptibility, and use, respectively., Aims and Methods: In total 630 young adults (18-25 years) completed an online Qualtrics panels survey in 2021. Participants were informed that TFN pouches contain synthetic nicotine as opposed to TDN. Participants reported on comparative risk perceptions for TFN versus TDN pouches and on TFN pouch awareness, susceptibility, and use. Unadjusted between-group comparisons and adjusted binary logistic regressions were run to examine relationships between product perceptions and TFN pouch awareness, susceptibility, and use., Results: Participants were aware of (37.3%), susceptible to (29.2%), or had used TFN pouches (3.8%). In unadjusted comparisons, TFN pouch awareness, susceptibility, and use were associated with disproportionately perceiving TFN pouches as less harmful or otherwise better than TDN pouches. In adjusted models, relationships between favorable perceptions and both TFN pouch awareness and susceptibility remained significant., Conclusions: The descriptor "tobacco-free" may impact risk perceptions and the appeal of nicotine pouches among young adults. While no direct relationship was observed between TFN perceptions and TFN pouch use in the adjusted model, perceptions remained related to product awareness and susceptibility, which may be linked to future use. Continued surveillance is needed to fully determine how the term "tobacco-free" on product packaging and advertising impacts longitudinal public health outcomes., Implications: Nicotine pouches originally contained TDN. Today, numerous brands of synthetic nicotine pouches, which are often marketed as "tobacco-free," are available on the market. We informed participants that "tobacco-free nicotine" pouches contain synthetic nicotine and examined comparative risk perceptions (i.e. tobacco-free vs. TDN pouches) and TFN pouch awareness, susceptibility, and use. Perceiving tobacco-free nicotine pouches as less harmful than tobacco-derived pouches was associated with product awareness, susceptibility, and use in unadjusted models and with awareness and susceptibility in adjusted models. Restricting the term "tobacco-free" may become necessary if the term inaccurately reduces product risk perceptions or increases product appeal., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: E-cigarette liquid nicotine concentrations typically are labeled as mg/mL or percent, which poorly convey nicotine strength to users. We evaluated whether four novel nicotine concentration labels better convey information about nicotine strength and addictiveness., Methods: Adolescents and young adults (N = 826) completed an online survey in 2020. Participants rated nicotine concentrations (3, 6, 18, 30, 40, and 50 mg/mL) from "no nicotine" to "very high nicotine" communicated using current market labels (mg/mL, percent) and four new labels (text-based, caution sign-shaped, horizonal stoplight, vertical thermometer) which used color, symbols, and verbal strength descriptors. Participants reported on perceived addictiveness for all labels viewed and rank-ordered labels on perceived ability to convey information accurately., Results: Participants ranked the vertical (77%) and horizontal (70%) labels in first or second place and mg/mL (59.1%) and percent (47.2%) in last or second-to-last place. All new labels conveyed nicotine strength more accurately than did market labels (M[SD] correct of 6: percent = 1.50[1.08]; mg/mL = 2.14[1.52]; caution = 5.23[1.37]; vertical thermometer = 5.28[1.51]; text = 5.33[1.36]; horizontal stoplight = 5.47[1.14]), with the horizontal label also outperforming the thermometer and caution labels. Underestimating nicotine strength was uncommon among all new labels (4.7-6.8%). The new labels also were associated with increased perceived addictiveness at higher concentrations (30, 40, and 50 mg/mL), although the thermometer label underperformed the others. When considering perceived nicotine strength, rates of strength underestimates, perceived addictiveness, and rank ordering, the horizontal stoplight label performed best., Conclusions: Novel labeling could improve understanding of nicotine strength and e-cigarette-related risk., Implications: Extending prior research showing that adolescents and young adults who use Electronic Nicotine Delivery Systems (ENDS) have difficulty understanding nicotine concentrations labeled using mg/mL and percent nicotine, the current study demonstrates that novel nicotine concentration labels can improve understanding of nicotine strength and influence perceptions of addictiveness among young ENDS users. While four novel labels were tested, each outperforming current market labeling, the novel label that resembles a horizontal stoplight performed best. The study provides proof-of-concept that creating an easy-to-understand nicotine concentration label is possible and that new labeling better conveys information about nicotine strength and addictiveness., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Assessing youth vaping expectancies using a psychometrically sound measure can improve understanding of e-cigarette susceptibility and use., Aims and Methods: We evaluated the psychometric properties of the Short-Form Vaping Consequences Questionnaire (SF-VCQ), an expectancy measure previously validated with adults, within a sample of 1753 high school adolescents who completed an online, school-based survey in Fall 2020 (51.6% female; 15.56 [1.22] years old; 46.6% non-Hispanic white; 26.9% reported lifetime but no past-30-day vaping; 12.6% reported past-30-day vaping). Analyses included confirmatory factor analysis, internal consistency, measurement invariance, between-group differences, and test-criterion relationships., Results: The four-factor structure was confirmed and was scalar invariant by lifetime and past-month vaping status, sex, and race. All subscales were internally reliable (mean α = 0.94). The subscales were sensitive to differences based on sex, race, vaping susceptibility among never users, and lifetime and past-month vaping status. For example, students who vaped in the past-month held weaker expectancies for negative consequences but stronger expectancies for positive reinforcement, negative reinforcement, and appetite/weight control compared to lifetime vapers. Unadjusted relationships within the subsamples of lifetime and past-month vapers provided evidence of convergent validity. Evidence for concurrent validity was observed for all samples after accounting for covariates. For example, expectancies for positive reinforcement, negative reinforcement, and appetite/weight control remained significantly associated with past-month vaping frequency., Conclusions: The SF-VCQ evidenced excellent internal reliability, scalar measurement invariance, and construct, convergent, and concurrent validity in samples of never, lifetime, and past-month adolescent e-cigarette users. Findings support using the SF-VCQ for assessing youths' vaping-related expectancies., Implications: The current study established the psychometric properties of the SF-VCQ for use among adolescents with and without vaping experience, including measurement invariance that permits direct comparisons of expectancies across these two groups. When considered in concert with previously published research in adults, the SF-VCQ provides researchers with a measure that can be used with both youth and adult samples. Observed relationships between positive expectancies and vaping susceptibility in vaping naïve youth and indices of vaping frequency in youth with vaping experience suggest that challenging positive expectancies may be a valuable addition to prevention and intervention efforts to reduce youth vaping., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: E-cigarette e-liquid nicotine concentrations typically are labeled as mg/mL or percent nicotine. We examined whether these metrics accurately convey nicotine strength to young e-cigarette users and if youth can compare concentrations presented in mg/mL and percent nicotine., Aims and Methods: Eight hundred and twenty-one adolescent and young adult e-cigarette users participated in the survey. Participants rated nicotine concentration strengths presented as mg/mL (0-60 mg/mL) and percent nicotine (0%-6%) from "no nicotine" to "very high nicotine." Participants also viewed pairs of nicotine concentrations (eg, 18 mg/mL vs. 5%) and indicated which concentration was stronger or if the concentrations were equivalent., Results: On average, participants correctly identified 5.92 (2.68) of 18 nicotine strengths, correctly identifying strengths labeled as mg/mL (3.47 [2.03]) more often than percent nicotine (2.45 [1.38], p < .001). Excluding nicotine-free, participants rated concentrations presented as mg/mL as stronger, more addictive, and more harmful than equivalent concentrations presented as percent nicotine. Participants seldom correctly identified that one concentration was stronger or that both were equivalent (7.58 [5.88] of 19 pairings), although they more often correctly identified the stronger concentration when it was presented in mg/mL (4.02 [SD = 3.01]) than in percent nicotine (2.53 [2.73], p < .001). The most consistent predictor of correct answers on these tasks was familiarity with using both products labeled as mg/mL and labeled as percent nicotine., Conclusions: Young e-cigarette users had difficulty understanding nicotine concentrations labeled using the most common metrics, raising concerns about inadvertent exposure to high nicotine levels and suggesting that a more intuitive labeling approach is needed., Implications: This study extends prior work showing that young e-cigarette users often are uncertain whether the e-liquids they use contain nicotine by demonstrating that adolescents and young adults have difficulty understanding nicotine concentrations labeled using the two most common metrics (mg/mL and percent nicotine). Errors generally underestimated nicotine strength, and users were not able to accurately compare nicotine concentrations presented as mg/mL and percent nicotine. Difficulty understanding labeling metrics persisted even after accounting for user characteristics like age and vaping experience, suggesting that a novel, easy to understand labeling system is needed to convey information about nicotine strength accurately., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: The purpose of this study was to evaluate a pilot preoperative contingency management (CM) intervention for smoking abstinence., Aims and Methods: This multisite pilot study was conducted at two cancer center-based tobacco treatment programs. Participants who were smoking, diagnosed with or suspected to have any type of operable cancer, and had a surgical procedure scheduled in the next 10 days to 5 weeks (N = 40) were randomized to receive standard care plus monitoring only (MO) or CM prior to surgery. All patients received breath carbon monoxide (CO) tests 3 times per week, nicotine patches, and counseling. The CM group also earned payments for self-reported smoking abstinence confirmed by CO breath test ≤6 ppm on an escalating schedule of reinforcement (with a reset if they smoked). Seven-day point prevalence abstinence rates on the day of surgery and at 3-month follow-up were compared between groups using repeated measures log-linear regression models utilizing generalized estimating equations. Participants lost to follow-up are assumed to have returned to smoking., Results: The sample was 50% female and 75% White. In covariate adjusted models, patients in the CM group had a greater probability of reported abstinence. On the day of surgery (end of treatment), 52% of CM patients were abstinent compared with 16% of patients in MO (risk ratio = 3.2 [1.1-9.3]; p = .03). At the 3-month follow-up, 43% of CM patients were abstinent compared with 5% in MO (risk ratio = 8.4 [1.5-48.3]; p = .02)., Conclusions: Providing monetary incentives contingent on abstinence prior to cancer surgery may produce significant improvements in smoking abstinence rates relative to breath CO MO., Implications: In this pilot preoperative CM intervention for smoking abstinence, patients receiving a CM intervention prior to cancer surgery had a greater probability of smoking abstinence at the end of treatment compared with a breath MO group (52% vs. 16%, respectively). Thus, providing monetary incentives contingent on abstinence may produce significant improvements in smoking abstinence rates prior to cancer surgery relative to breath CO monitoring., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved.For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: JUUL, a closed system e-cigarette with disposable pods, is popular among youth, with positive attributes of this product linked to current use by youth. However, many youth try JUUL and do not continue using; understanding differences in the appeal of this device between current users and those who chose not to continue use can inform regulation and prevention efforts. The aim of the current study is to compare JUUL appeal in youth among past users (ie, used, but not in past month) and current users (ie, used in past month)., Methods: A cross-sectional survey was conducted in four Connecticut high schools in Spring 2018. This survey assessed JUUL use and reasons for liking/disliking JUUL, including its' pharmacological effects (eg, nicotine "buzz"), product characteristics (eg, flavors), peer influence, appeal compared to other e-cigarettes, and concealability. Logistic regressions were conducted to examine differences in liking/disliking JUUL by use status (past vs. current)., Results: Among JUUL users (N = 1374; 43% of total sample), 30.4% were past users and 69.6% were current users. Compared to current users, past users were less likely to like JUUL for positive pharmacological effects (eg, nicotine "buzz"), product characteristics (eg, flavors), and peer use and more likely to dislike JUUL for the adverse pharmacological effects (eg, headache), product characteristics (eg, flavors), and for "other" reasons (open-ended response; eg, perceived harm)., Conclusions: Findings suggest that altering JUUL appeal through regulating nicotine content and flavors may be key in policy aimed at shifting youth to become past JUUL users., Implications: This study investigates how current and past youth JUUL users differ in their report of the appeal of JUUL. Past users are less likely to report experiencing positive pharmacological effects and product characteristics of JUUL and are less likely to report appeal due to peer use. Understanding how appeal of JUUL may differ among past and current users can aid in our understanding of how to regulate these products so that they are less appealing to current youth users., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Waterpipe use remains popular among youth with the availability of flavored shisha tobacco being one of the main drivers of waterpipe use. Although waterpipe mainstream toxicant emissions are well understood, less is known about the carryover of flavorants such as vanillin, benzaldehyde, and eugenol. In this study, flavored waterpipe tobacco was analyzed for flavorants and nicotine, and subsequent carryover to mainstream smoke., Methods: Flavorants vanillin, benzaldehyde, and eugenol, and nicotine were quantified in vanilla-, cherry-, and cinnamon-flavored shisha tobacco by gas chromatography/flame ionization detector and subsequently in waterpipe mainstream smoke generated by a smoking machine. The setup allowed for sampling before and after the water-filtration step., Results: Flavorant and nicotine content in smoke was reduced 3- to 10-fold and 1.4- to 3.1-fold, respectively, due to water filtration. Per-puff content of filtered waterpipe mainstream smoke ranged from 13 to 46 µg/puff for nicotine and from 6 to 55 µg/puff for flavorants., Conclusions: Although water filtration reduced flavor and nicotine content in waterpipe mainstream smoke, the detected flavorant concentrations were similar or higher to those previously reported in e-cigarette aerosol. Therefore, users could be drawn to waterpipes due to similar flavor appeal as popular e-cigarette products. Absolute nicotine content of waterpipe smoke was lower than in e-cigarette aerosol, but the differential use patterns of waterpipe (>100 puffs/session) and e-cigarette (mostly <10 puffs/session, multiple session throughout the day) probably result in higher flavorant and nicotine exposure during a waterpipe session. Strategies to reduce youth introduction and exposure to nicotine via waterpipe use may consider similar flavor restrictions as those for e-cigarettes., Implications: Although waterpipe mainstream smoke is well characterized for toxicants content, little is known about carryover of molecules relevant for appeal and addiction: flavorants and nicotine. This study shows that flavorant content of waterpipe mainstream smoke is comparable or higher than e-cigarette aerosol flavorant content. Regulatory action to address tobacco use behaviors targeting the availability of flavors should also include other tobacco products such as flavored shisha tobacco., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Most tobacco use is initiated during adolescence and susceptibility is an important predictor of initiation. Research is needed to understand susceptibility across tobacco products among youth to inform prevention efforts., Aims and Methods: We surveyed 2945 students from four Southeastern Connecticut high schools in 2017. We assessed susceptibility to future use of seven different tobacco products (ie, cigarettes, e-cigarettes, hookah, cigars, cigarillos, blunts, and smokeless tobacco) among youth who had never used a tobacco product. Susceptibility was coded as any response other than "definitely not" to three items assessing (1) curiosity, (2) willingness to experiment with the product in the future, and (3) willingness to try if offered by a friend. Latent class analysis was used to identify patterns of susceptibility across multiple tobacco products and sociodemographic predictors of these classes., Results: Among n = 1246 youth who had never tried a tobacco product, 51.2% (n = 638) were susceptible to at least one product and 29.1% (n = 363) were susceptible to two or more products (average among susceptible youth: M = 2.4 products, SD = 1.7, range 1-7). Latent class analysis identified three classes: youth who were: (1) susceptible to all products (5.6%), (2) susceptible to e-cigarettes, hookah, and blunts (23.6%), and (3) mostly non-susceptible to all products (70.8%). In a multivariable model, demographic variables and peer tobacco use predicted class membership., Conclusions: We observed high rates of susceptibility to non-traditional tobacco products among youth, and many youth were susceptible to more than one product. Targeting susceptibility across multiple tobacco products may be important for reducing youth tobacco use., Implications: Patterns of polytobacco use susceptibility were identified among youth who had never previously used tobacco products. Many youth were susceptible to more than one product and we observed three distinct classes of susceptibility among youth: those who were mostly non-susceptible, those who were susceptible to alternative or non-traditional tobacco products (e-cigarettes, hookah, and blunts), and those who were susceptible to all tobacco products. These findings suggest the importance of addressing susceptibility across multiple tobacco products., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved.For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Evaluations of multiple tobacco product use and temporal changes in patterns of use are complicated by a large number of combinations and transitions. Visualization tools could easily identify most common patterns and transitions., Methods: Set intersection bar plots describe ever use of five tobacco products among 12-17 years old youth in wave 1 of the Population Assessment of Tobacco and Health (PATH) study (N = 11 497). Heat maps visualize unweighted frequencies of transitions from ever use at wave 1 (2013-2014) to past 12-month use at wave 2 (2014-2015). Weighted calibrated heat maps assess differences in relative frequencies of transitions by pattern at wave 1 and identify differences in transitions by sex., Results: The most common tobacco product ever use patterns in wave 1 were of cigarettes only, e-cigarettes only or hookah only, followed by ever use of both cigarettes and e-cigarettes. Initiation of use between waves was uncommon. The most frequent transition among those who reported use at wave 2 but not at wave 1 (N = 971) was to e-cigarette use (N = 301). However, among e-cigarette-only ever users at wave 1 (N = 260), about half did not report any product use at wave 2. Use of three or more products remained stable. Adolescent girls compared to boys appeared more likely to report hookah use at both waves., Conclusion: Set intersection bar plots and heat maps are useful for visualizing tobacco product use patterns and transitions, especially for multiple products. Both techniques could identify common problematic tobacco use patterns across and within populations., Implications: Given the growing complexity of the youth tobacco use landscape, approaches to efficiently communicate patterns of multiple tobacco product use should be used more often. This study introduces set intersection bar plots and modified versions of heat maps to the tobacco product literature and illustrates their use in the PATH youth sample. These techniques are useful for visualizing absolute and relative frequencies of multiple possible patterns and transitions. They also suggest targets for subsequent statistical inference such as sex differences in hookah use. The methods can be applied more generally for data visualization wherever large number of combinations occurs., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Cannabis-including blunts (cannabis rolled in tobacco-containing cigar casing) -is commonly the first substance used among adolescents and may increase the likelihood of subsequent initiation of combustible tobacco products., Aims and Methods: Data were pooled from two prospective studies of adolescents in California and Connecticut (total N = 4594). Logistic regression models assessed the association of baseline ever blunt use and ever non-blunt cannabis use (vs. never cannabis use) with subsequent initiation of any combustible tobacco-only product (ie, cigarettes, cigars, or cigarillos) by 1-year follow-up after adjustment for demographic characteristics and other tobacco product use at baseline. We also assessed whether estimates differed by prior e-cigarette or hookah use at baseline., Results: Among never combustible tobacco-only product users (N = 2973), 221 (7.4%) had ever used a blunt and 114 (3.8%) had ever used only non-blunt cannabis at baseline. Blunt use (adjusted odds ratio [AOR] = 1.98, 95% confidence interval [CI]: 1.30 to 3.01) and non-blunt cannabis use (AOR = 2.38, 95% CI: 1.41 to 4.00) were independently associated with greater odds of combustible tobacco-only product initiation by follow-up. Among those who had not tried e-cigarettes or who had not tried hookah, blunt use and non-blunt cannabis use were associated with significantly increased odds of combustible tobacco product initiation; among those who had tried e-cigarettes or hookah, the association was not significant., Conclusions: We found blunt and non-blunt cannabis use to be associated with subsequent combustible tobacco-only product initiation, particularly among adolescents who had not also tried other products containing nicotine., Implications: Adolescent-focused tobacco prevention efforts should consider incorporating cannabis products, including blunts. More research is needed to understand how blunt use and cannabis use more broadly are associated with initiation of tobacco products., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Changes in tobacco products, use patterns, and assessment technology in the last 15 years led the Society for Research on Nicotine and Tobacco (SRNT) Treatment Research Network to call for an update to the 2003 SRNT recommendations for assessing abstinence in clinical trials of smoking cessation interventions., Methods: The SRNT Treatment Research Network convened a group of investigators with decades of experience in conducting tobacco treatment clinical trials. To arrive at the updated recommendations, the authors reviewed the recommendations of the prior SRNT Workgroup as well as current literature. Ten additional experts in the field provided feedback on this paper and these recommendations., Results: With respect to defining abstinence, the authors recommend: (1) continuing to use the definition of no use of combustible tobacco products (regardless of use of noncombustible tobacco products [e.g., snus] and alternative products [e.g., e-cigarettes]) and collecting additional data to permit alternate abstinence definitions; (2) no use of combustible or smokeless tobacco products; and (3) no use of combustible or smokeless tobacco products or alternative products, as appropriate for the research question being addressed. The authors also recommend reporting point prevalence and prolonged abstinence at multiple timepoints (end of treatment, ≥3 months after the end of treatment, and ≥6 months postquit or posttreatment initiation)., Conclusions: Defining abstinence requires specification of which products a user must abstain from using, the type of abstinence (i.e., point prevalence or continuous), and the duration of abstinence. These recommendations are intended to serve as guidelines for investigators as they collect the necessary data to accurately describe participants' abstinence during smoking cessation clinical trials., Implications: This paper provides updated recommendations for defining abstinence in the context of smoking cessation treatment clinical trials., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved.For permissions, please e-mail: journals.permissions@oup.com.)

The Tobacco Regulatory Science Program is a collaborative research effort between the National Institutes of Health (NIH) and the Food and Drug Administration (FDA). In 2013, the NIH funded 14 Tobacco Centers of Regulatory Science (TCORS), which serve as partners in establishing research, training, and professional development programs to guide FDA. Each of the fourteen TCORS, and two other NIH-funded research programs, the Center for the Evaluation of Nicotine in Cigarettes (CENIC) and the Consortium on Methods Evaluating Tobacco (COMET), pursued specific research themes relevant to FDA's priorities. A key mandate for FDA is to reduce tobacco use among young people. This article is a review of the peer-reviewed research, including published and in-press manuscripts, from the TCORS, CENIC, and COMET, which provides specific data or other findings on youth (ages 10-18 years) and/or young adults (ages 18-34 years), from 2013 to 2018. Citations of all TCORS, CENIC, and COMET articles from September 2013 to December 2017 were collected by the TCORS coordinating center, the Center for Evaluation and Coordination of Training and Research. Additional citations up to April 30, 2018 were requested from the principal investigators. A scoring rubric was developed and implemented to assess study type, primary theme, and FDA priority area addressed by each article. The major subareas and findings from each priority area are presented. There were 766 articles in total, with 258 (34%) focusing on youth and/or young adults. Findings relevant to FDA from this review concern impact analysis, toxicity, health effects, addiction, marketing influences, communications, and behavior., Implications: The Tobacco Centers of Regulatory Science, CENIC, and COMET have had a high output of scientific articles since 2013. These Centers are unique in that the FDA supports science specifically to guide future regulatory actions. The 258 articles that have focused on youth and/or young adults are providing data for regulatory actions by the FDA related to the key priority areas such as the addictiveness of non-cigarette products, the effects of exposure to electronic cigarette marketing on initiation and cessation, and the impact of flavored products on youth and young adult tobacco use. Future regulations to reduce tobacco use will be guided by the cumulative evidence. These Centers are one innovative mechanism to promote important outcomes to advance tobacco regulatory science., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved.For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Characterizing flavors are widely available in e-cigarettes and motivate initiation and continued use. Flavors may enhance appeal and facilitate development of addiction to tobacco products through modulation of tobacco products' reinforcing or aversive actions. Palatable flavors (eg, fruit) may increase appeal through primary reinforcing properties. Menthol's cooling and anesthetic effects may increase appeal by counteracting nicotine's aversive effects. Genetics provide a method for modeling individual differences in sensitivity to nicotine's effects. A common polymorphism, rs16969968, encoded in the α5 nicotinic acetylcholine receptor subunit gene (CHRNA5), is a well-recognized marker for smoking risk and reduces sensitivity to nicotine aversiveness., Methods: This pilot study tested how flavors impacted e-cigarette appeal and self-administration. In a single testing day, cigarette smokers (N = 32; 94% menthol-smokers) self-administered e-cigarettes containing e-liquids differing in nicotine level (0 mg/mL, 24 mg/mL) and flavor (unflavored, menthol, fruit-flavored) within directed and ad libitum e-cigarette paradigms. Subjective drug effects, number of puffs, rs16969968 genotype, plasma nicotine, and menthol glucuronide levels were collected., Results: Menthol partially ameliorated nicotine aversiveness; fruit did not. In nicotine's absence, fruit flavor increased self-reported preference and ad libitum use relative to menthol-containing or unflavored e-liquids. Individuals with high-smoking-risk rs16969968 genotype (N = 7) reported greater craving alleviation following directed administration of nicotine-containing e-liquids, showed a trend rating nicotine-containing e-liquids as less harsh, and self-administered more nicotine during ad libitum compared to individuals with low-smoking-risk genotype (N = 23)., Conclusions: While menthol countered aversiveness of nicotine-containing e-liquids, fruit flavor increased appeal of nicotine-free e-liquids. These preliminary findings suggest menthol and fruit flavor increase e-cigarettes' appeal through distinct mechanisms., Implications: This study provides a detailed characterization of the effects of flavors (unflavored, menthol, fruit), nicotine (0 mg/mL, 24 mg/mL) and their interactions on the subjective drug effects and ad libitum self-administration of e-cigarettes. Genetics were used to assess these effects in higher-smoking-risk (diminished sensitivity to nicotine aversiveness) and lower-risk groups. Findings could inform impact of regulation of flavors or nicotine in e-cigarettes, and their impacts on vulnerable sub-populations., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Prevalence estimates of electronic cigarette (e-cigarette) use may underestimate actual use in youth. Confusion resulting from the fact that a multitude of devices (eg, vape pens, JUULs) fall under the umbrella term "e-cigarettes," the use of different names to refer to e-cigarettes (eg, vapes, electronic vaping devices), and the use of different terminology to refer to e-cigarette use (eg, "vaping," "JUULing"), may lead some young e-cigarette users to incorrectly indicate nonuse. Therefore, we compared rates of endorsing lifetime e-cigarette use when adolescents were asked about lifetime e-cigarette use in two different ways., Methods: In May to June 2018, a total of 1960 students from two high schools in Connecticut completed a computerized, school-based survey. Participants first reported on lifetime "e-cigarette" use and, subsequently, on lifetime use of five different e-cigarette devices: disposables, cig-a-likes, or E-hookahs; vape pens or Egos; JUULs; pod systems other than JUULs such as PHIX or Suorin; and advanced personal vaporizers or mods., Results: In total, 35.8% of students endorsed lifetime "e-cigarette" use, whereas 51.3% endorsed lifetime use of at least one e-cigarette device. The kappa statistic indicated only 66.6% agreement between the methods of assessing e-cigarette use. Overall, 31.5% of adolescents who endorsed lifetime device use did not endorse lifetime "e-cigarette" use, although rates of discordant responding varied across subgroups of interest (eg, sex, race)., Conclusions: Assessing adolescents' use of specific e-cigarette devices likely yields more accurate results than assessing the use of "e-cigarettes." If these findings are replicated in a nationally representative sample, regulatory efforts requiring all e-cigarette devices to be clearly labeled as "e-cigarettes" may help to reduce confusion., Implications: Different prevalence estimates of lifetime e-cigarette use were obtained depending on the way that prevalence was assessed. Specifically, fewer adolescents (35.8%) endorsed lifetime e-cigarette use when they were asked "Have you ever tried an e-cigarette, even one or two puffs?" than when they were queried about lifetime use of five different e-cigarette devices (51.3%). Among those who endorsed lifetime use of at least one specific e-cigarette device, 31.5% did not endorse lifetime "e-cigarette" use. These findings suggest that when assessing adolescents' lifetime e-cigarette use, using of terms referring to specific devices likely produces more accurate prevalence estimates than using the term "e-cigarettes.", (© The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Psychometrically sound measures of e-cigarette dependence are lacking., Methods: We modified the PROMIS Item Bank v1.0-Smoking: Nicotine Dependence for All Smokers for use with e-cigarettes and evaluated the psychometrics of the 22-, 8-, and 4-item adapted versions, referred to as The E-cigarette dependence scale (EDS). Adults (1009) who reported using e-cigarettes at least weekly completed an anonymous survey in summer 2016 (50.2% male, 77.1% White, mean age 35.81 [10.71], 66.4% daily e-cigarette users, 72.6% current cigarette smokers). Psychometric analyses included confirmatory factor analysis, internal consistency, measurement invariance, examination of mean-level differences, convergent validity, and test-criterion relationships with e-cigarette use outcomes., Results: All EDS versions had confirmable, internally consistent latent structures that were scalar invariant by sex, race, e-cigarette use (nondaily/daily), e-liquid nicotine content (no/yes), and current cigarette smoking status (no/yes). Daily e-cigarette users, nicotine e-liquid users, and cigarette smokers reported being more dependent on e-cigarettes than their counterparts. All EDS versions correlated strongly with one another, evidenced convergent validity with the Penn State E-cigarette Dependence Index and time to first e-cigarette use in the morning, and evidenced test-criterion relationships with vaping frequency, e-liquid nicotine concentration, and e-cigarette quit attempts. Similar results were observed when analyses were conducted within subsamples of exclusive e-cigarette users and duals-users of cigarettes and e-cigarettes., Conclusions: Each EDS version evidenced strong psychometric properties for assessing e-cigarette dependence in adults who either use e-cigarette exclusively or who are dual-users of cigarettes and e-cigarettes. However, results indicated little benefit of the longer versions over the 4-item EDS, which provides an efficient assessment of e-cigarette dependence., Implications: The availability of the novel, psychometrically sound EDS can further research on a wide range of questions related to e-cigarette use and dependence. In addition, the overlap between the EDS and the original PROMIS that was developed for assessing nicotine dependence to cigarettes provides consistency within the field., (Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco 2018.)

Introduction: This paper describes different methods for analyzing counts and illustrates their use on cigarette and marijuana smoking data., Methods: The Poisson, zero-inflated Poisson (ZIP), hurdle Poisson (HUP), negative binomial (NB), zero-inflated negative binomial (ZINB) and hurdle negative binomial (HUNB) regression models are considered. The different approaches are evaluated in terms of the ability to take into account zero-inflation (extra zeroes) and overdispersion (variance larger than expected) in count outcomes, with emphasis placed on model fit, interpretation, and choosing an appropriate model given the nature of the data. The illustrative data example focuses on cigarette and marijuana smoking reports from a study on smoking habits among youth e-cigarette users with gender, age, and e-cigarette use included as predictors., Results: Of the 69 subjects available for analysis, 36% and 64% reported smoking no cigarettes and no marijuana, respectively, suggesting both outcomes might be zero-inflated. Both outcomes were also overdispersed with large positive skew. The ZINB and HUNB models fit the cigarette counts best. According to goodness-of-fit statistics, the NB, HUNB, and ZINB models fit the marijuana data well, but the ZINB provided better interpretation., Conclusion: In the absence of zero-inflation, the NB model fits smoking data well, which is typically overdispersed. In the presence of zero-inflation, the ZINB or HUNB model is recommended to account for additional heterogeneity. In addition to model fit and interpretability, choosing between a zero-inflated or hurdle model should ultimately depend on the assumptions regarding the zeros, study design, and the research question being asked., Implications: Count outcomes are frequent in tobacco research and often have many zeros and exhibit large variance and skew. Analyzing such data based on methods requiring a normally distributed outcome are inappropriate and will likely produce spurious results. This study compares and contrasts appropriate methods for analyzing count data, specifically those with an over-abundance of zeros, and illustrates their use on cigarette and marijuana smoking data. Recommendations are provided.

Background: Electronic cigarettes (ECs) can influence nicotine addiction by delivering aerosolized nicotine. We investigated if nicotine from ECs is delivered to the brain β2*-nicotinic acetylcholine receptors (β2*-nAChR) and how this relates to the behavioral effects and nicotine delivery from cigarettes., Methods: Seven nicotine users participated in positron emission tomography (PET) studies with (-)-[18F]Flubatine before and after nicotine challenge with 0, 8, and 36 mg/ml nicotine in a 3.3 Volt, 1.5 Ohm EC or a standard tobacco cigarette. Craving was evaluated before and after product use., Results: Average β2*-nAChR occupancy was higher after 36 mg/ml EC challenge compared to 8 mg/ml EC at trend level. Average β2*-nAChR occupancy after tobacco cigarette smoking was 68 ± 18% and was not different compared with 8 mg/ml (64 ± 17%,) or 36 mg/ml (84 ± 3%) nicotine in EC users. Area under the curve (AUC) of blood nicotine level was higher in the cigarette smoking group compared with the 8mg/ml group (p = 0.03), but similar compared with the 36 mg/ml EC (p = 0.29). Drug craving was reduced after use of the tobacco cigarette, 8 mg/ml EC, and 36 mg/ml EC., Conclusions: In this novel investigation of EC effects at β2*-nAChRs, we show that average β2*-nAChR occupancy was higher after 36 mg/ml EC challenge compared with 8 mg/ml EC. Receptor occupancy and arterial blood nicotine levels after cigarette smoking were similar to 36 mg/ml EC use under controlled conditions. These findings suggest that the ECs studied here have abuse liability and may provide an adequate alternative nicotine delivery system for cigarette smokers., Implications: This is the first study to directly determine the neurologic effects of electronic cigarettes on human brain beta-2 nicotinic acetylcholine receptors using PET neuroimaging with (-)-[18F]Flubatine, a novel radiotracer. Our findings suggest that the e-cigarettes studied here have abuse liability and may provide an adequate alternative nicotine delivery system for cigarette smokers.

Background: A recent study of adult smokers who vape found that disposable/cigalike electronic (e-) cigarette devices were more commonly used than later generation devices. However, whether these trends reflect patterns among adolescents and young adults, many of whom have limited or no history of combustible cigarette use, has not been studied., Methods: Participants were drawn from eight locally, regionally, and US nationally representative studies. Surveys took place between Fall 2014 and Spring 2016; participants were residents of California (3 studies), Texas (2 studies), Connecticut (1 study), or randomly selected from the US population (2 studies). Data were collected from middle and high school students (4 studies), young adults under 30 (3 studies), or a mixture (1 study) to assess type of e-cigarette device used among past-30 day e-cigarette users: disposable/cigalike, or later generation e-cigarette device., Results: Fewer than 15% of participants in each study reported primarily using a disposable/cigalike device in the past month (across all studies: 7.5%; 95%CI: 4.9%, 10.5%). The proportion using later generation devices ranged from 58% to 86% across studies; overall, 77.0% (95%CI: 70.5%, 82.9%) reported primary use of a later generation device. Combined, 13.2% (95%CI: 5.9%, 22.8%) reported "don't know" or were missing data., Conclusions: Among adolescent and young adult e-cigarette users, primary use of disposable/cigalike devices was rare. Future research should continue to evaluate the type of device used by adolescents and young adults, as these data may be relevant to regulatory oversight of e-cigarettes recently acquired by the Food and Drug Administration Center for Tobacco Products., Implications: In this pooled analysis of adolescent and young adult vapers, primary use of later generation e-cigarette devices was substantially more common than use of disposable/cigalike devices. The type of device predominantly used by adolescents and young adults has regulatory implications for policy to reduce adolescent use of e-cigarettes., (© The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Identifying youth at risk for future e-cigarette use is critical for informing prevention efforts. Prior research established measures of susceptibility to conventional cigarettes, and this study aimed to examine whether items adapted for e-cigarette susceptibility predicted subsequent e-cigarette use among never e-cigarette users., Methods: Longitudinal school-wide survey data were collected from middle and high school students in Fall 2013 (wave 1) and Spring 2014 (wave 2). Among never e-cigarette users at wave 1 (n = 1720), e-cigarette susceptibility was measured by two items assessing anticipation of experimenting with e-cigarettes in the future and willingness to use an e-cigarette if offered by a best friend. Logistic regression models examined susceptibility as a predictor of e-cigarette initiation and past 30-day use 6 months later at wave 2. Models were clustered by school and controlled for sex, age, race, SES, and other substance use (alcohol, marijuana, and other tobacco)., Results: In total, 8.9% (n = 153) of youth initiated e-cigarettes and 3.7% (n = 63) reported past 30-day use at wave 2. E-cigarette susceptibility was a significant independent predictor of subsequent initiation (OR = 4.27, 95% CI = 3.12-5.85) and past 30-day e-cigarette use (OR = 5.10, 95%CI = 3.38-7.68) 6 months later. Susceptible youth were more likely to be male, older, and have used alcohol, marijuana, or other tobacco products., Conclusions: These findings provide initial support for adapting two susceptibility items to identify adolescents at risk for future e-cigarette use. Identifying strategies that are effective for targeting susceptible youth and preventing future e-cigarette use will be critical areas for future research., Implications: More than a quarter of the sample who reported both a willingness to try e-cigarettes if offered by a best friend and anticipation of experimenting with e-cigarettes in the future went on to try e-cigarettes within the academic year, suggesting that targeting this group will be critical for preventing youth e-cigarette initiation. There were notable demographic differences between susceptible and non-susceptible youth, suggesting targeting e-cigarette prevention efforts to male students who have used other substances may be especially important for preventing future e-cigarette use. Research is needed to determine the most effective prevention strategies to reach susceptible youth., (© The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: This exploratory study examines the prevalence and predictors of current and former smokers' use of electronic (e-) cigarettes for smoking cessation among a sample of adolescent and young adult established smokers., Methods: We conducted school-wide surveys in two middle (n = 1166) and four high schools (n = 3614) in fall 2013 and one public college (n = 625) in spring 2014. We analyzed data from 189 established smokers (reported smoking 100 cigarettes in their lifetime) who also reported ever-use of e-cigarettes (50.7% female, 89.4% White race, Mage 18.3 [SD = 2.8]). We further classified participants as current smokers (reported past-month cigarette smoking) and former smokers (no past-month smoking). Adjusted logistic regression assessed associations of using e-cigarettes to quit smoking with demographic, cigarette and e-cigarette use patterns, e-cigarette flavor preference, and risk perception variables., Results: Overall, 41.8% of the sample reported that they "have used an e-cigarette to quit smoking." In adjusted models, older age, White race, higher e-cigarette frequency, and preference for using a combination of e-cigarette flavors predicted increased odds of having used e-cigarettes to quit smoking (p < .05). Using e-cigarettes to quit smoking was not associated with current or former cigarette smoking status or perceptions that "e-cigarettes help people quit smoking" or "e-cigarettes are safer than quit smoking medications.", Conclusions: Adolescents and young adults who report more frequent e-cigarette use and preference for using flavor combinations are more likely to use e-cigarettes for smoking cessation. Future studies are needed to determine whether e-cigarette use leads to tobacco abstinence in youth smokers., Implications: Among young established smokers, more frequent e-cigarette use and preference for using flavors mixed together, but not perceptions of harmfulness of e-cigarettes or comparative safety of e-cigarettes compared with cigarettes or other smoking cessation medications or helpfulness of e-cigarettes in quitting smoking, are associated with using e-cigarettes for smoking cessation., (© The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Research has shown that adults perceive that electronic cigarettes (e-cigarettes) are effective for smoking cessation, yet little is known about adolescents and young adults' perceptions of e-cigarettes for quitting cigarette smoking. This study describes middle, high school, and college students' beliefs about, and experiences with, e-cigarettes for cigarette smoking cessation., Methods: We conducted 18 focus groups (n = 127) with male and female cigarette smokers and nonsmokers in 2 public colleges, 2 high schools, and 1 middle school in Connecticut between November 2012 and April 2013. Participants discussed cigarette smoking cessation in relation to e-cigarettes. Verbatim transcripts were analyzed using thematic analysis., Results: All participants, regardless of age and smoking status, were aware that e-cigarettes could be used for smoking cessation. College and high school participants described different methods of how e-cigarettes could be used for smoking cessation: (a) nicotine reduction followed by cessation; (b) cigarette reduction/dual use; and (c) long-term exclusive e-cigarette use. However, overall, participants did not perceive that e-cigarette use led to successful quitting experiences. Participants described positive attributes (maintenance of smoking actions, "healthier" alternative to cigarettes, and parental approval) and negative attributes (persistence of craving, maintenance of addiction) of e-cigarettes for cessation. Some college students expressed distrust of marketing of e-cigarettes for smoking cessation., Conclusions: Adolescent and young adult smokers and nonsmokers perceive that there are several methods of using e-cigarettes for quitting and are aware of both positive and negative aspects of the product. Future research is needed to determine the role of e-cigarettes for smoking cessation in this population., (© The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Understanding why young people try and stop electronic cigarette (e-cigarette) use is critical to inform e-cigarette regulatory efforts., Methods: We conducted 18 focus groups (N = 127) in 1 middle school (MS), 2 high schools (HSs), and 2 colleges in Connecticut to assess themes related to e-cigarette experimentation and discontinuation. We then conducted surveys to evaluate these identified themes in 2 MSs, 4 HSs, and 1 college (N = 1,175) to explore whether reasons for e-cigarette experimentation and/or discontinuation differed by school level or cigarette smoking status., Results: From the focus groups, we identified experimentation themes (i.e., curiosity, flavors, family/peer influence, easy access, and perceptions of e-cigarettes as "cool" and as a healthier/better alternative to cigarettes) and discontinuation themes (i.e., health concerns, loss of interest, high cost, bad taste, and view of e-cigarettes as less satisfying than cigarettes). The survey data showed that the top reasons for experimentation were curiosity (54.4%), appealing flavors (43.8%), and peer influences (31.6%), and the top reasons for discontinuation were responses related to losing interest (23.6%), perceiving e-cigarettes as "uncool" (16.3%), and health concerns (12.1%). Cigarette smokers tried e-cigarettes because of the perceptions that they can be used anywhere and to quit smoking and discontinued because they were not as satisfying as cigarettes. School level differences were detected., Conclusions: E-cigarette prevention efforts toward youth should include limiting e-cigarette flavors, communicating messages emphasizing the health risks of use, and changing social norms surrounding the use of e-cigarettes. The results should be interpreted in light of the limitations of this study., (© The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: There is limited evidence on electronic cigarette (e-cigarette) use among U.S. adolescents., Methods: Cross-sectional, anonymous surveys conducted in 4 high schools (HS; n = 3,614) and 2 middle schools (MS; n = 1,166) in Connecticut in November 2013 examined e-cigarette awareness, use patterns, susceptibility to future use, preferences, product components used (battery type, nicotine content, flavors), and sources of marketing and access., Results: High rates of awareness (MS: 84.3%; HS: 92.0%) and of lifetime (3.5% MS, 25.2 % HS) and current (1.5% MS, 12% HS) use of e-cigarettes was observed. Among those who had not tried e-cigarettes, 26.4% of MS and 31.7% of HS students reported being susceptible to future use. Males (OR = 1.70, p < .01), older students (OR = 1.39, p < .05), Caucasians (OR = 2.01, p < .001), ever cigarette smokers (OR = 13.04, p < .001), and current cigarette smokers (OR = 65.11, p < .001) were more likely to be lifetime e-cigarette users and to report greater future susceptibility (males: OR = 1.30; Caucasians: OR = 1.14; ever cigarette smokers; OR = 3.85; current cigarette smokers; OR = 9.81; ps < .01-.001). Among MS students who were lifetime e-cigarette users, 51.2% reported that e-cigarette was the first tobacco product they had tried. E-cigarettes that were rechargeable and had sweet flavors were most popular. Smokers preferred e-cigarettes to cigarettes. Current cigarette smokers were more likely to initiate with nicotine-containing e-cigarettes, and ever and never cigarette smokers to initiate with e-cigarettes without nicotine. Primary sources for e-cigarette advertisements were televisions and gas stations and, for acquiring e-cigarettes, were peers., Conclusions: Longitudinal monitoring of e-cigarette use among adolescents and establishment of policies to limit access are imperatively needed., (© The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Menthol cigarette and marijuana use among adolescents is high; however, little is known about dual use in this age. Thus, we examined these rates among 2 samples of adolescents in Connecticut., Methods: Study 1 examined a school-wide survey assessing variables related to cigarettes and marijuana among high school students (N = 837 [13% smokers]), and Study 2 examined these factors using baseline data of high school-aged, treatment-seeking, daily cigarette smokers prior to quitting (N = 132)., Results: In Study 1, lifetime marijuana use among all adolescents was 33% and past 30-day marijuana use was 21%. Among cigarette smokers, 55% reported smoking menthol cigarettes, 84% reported lifetime marijuana use, and 66% reported past 30-day marijuana use. Multivariate-adjusted logistic regression models indicated that cigarette smokers, when compared with nonsmokers, had greater rates of lifetime (odds ratio [OR] = 10.91) and past 30-day marijuana use (OR = 10.44). Among smokers, use of menthol cigarettes, when compared with use of nonmenthol cigarettes, was associated with greater lifetime (OR = 5.05) but not past 30-day marijuana use. In Study 2 with daily smokers, 59% of adolescents reported use of menthol cigarettes and 66% reported past 30-day marijuana use. Compared with nonmenthol cigarette smokers, menthol cigarette smokers were more likely to report past 30-day marijuana use (OR = 2.44)., Conclusions: Cigarette smoking is associated with marijuana use, and among smokers, menthol cigarette smoking further increased the odds of marijuana use. More research on the dual use of marijuana and tobacco is needed to inform prevention and treatment of substance use.

Aim: Emerging racial/ethnic disparities in tobacco use behaviors and resulting long-term health outcomes highlight the importance of developing culturally tailored/targeted tobacco prevention and cessation interventions. This manuscript describes the efficacy and the components of prevention and cessation interventions developed for minority adolescents., Methods: Thirteen studies focused on culturally tailoring and targeting tobacco prevention/cessation interventions were selected and information on intervention design (type, number of sessions), setting (school or community), theoretical constructs, culture-specific components (surface/deep structures), and treatment outcomes were extracted., Results: Of the 13 studies, 5 focused on prevention, 4 on cessation, and 4 combined prevention and cessation, and most of the studies were primarily school-based, while a few used community locations. Although diverse minority groups were targeted, a majority of the studies (n = 6) worked with Hispanic adolescents. The most common theoretical construct examined was the Social Influence Model (n = 5). The overall findings indicated that culturally tailoring cessation interventions did not appear to improve tobacco quit rates among minority adolescents, but culturally tailored prevention interventions appeared to produce lower tobacco initiation rates among minority adolescents than control conditions., Conclusions: The results of review suggest that there is a critical need to develop better interventions to reduce tobacco use among minority adolescents and that developing a better understanding of cultural issues related to both cessation and initiation of tobacco use among minority populations is a key component of this endeavor.

Introduction: Psychosocial stress and impulsivity are each associated with smoking in adolescents. There is also evidence that stress can increase impulsive responding, and impulsive adolescent smokers attempting cessation are at greater risk of relapse. We performed a pilot investigation to examine stress-induced changes in response inhibition, inattention, and risk taking as related to smoking status and posttreatment smoking abstinence., Methods: Twelve adolescent smokers participating in a smoking cessation intervention and 15 adolescent nonsmokers completed a 2-session protocol assessing stress-related change in response inhibition and inattention (on the Conners' Continuous Performance Test-II), risk taking (on the Balloon Analogue Risk Task), nicotine withdrawal symptoms, and self-reported stress., Results: At baseline, smokers had greater inattentive responding and risk taking when compared with nonsmokers. Stress exposure led to significant increases in stress, anger, and depression in all participants and also increased nicotine craving (on the Minnesota Nicotine Withdrawal Scale item) and impulsive responding in smokers. After covarying for baseline differences in impulsivity/risk taking, smokers who were not abstinent at the end of treatment experienced greater stress-induced risk taking when compared with those who were abstinent., Conclusions: In all, it appears that response inhibition and risk taking may be differentially altered by stress exposure in adolescent smokers and nonsmokers and that adolescent smoking cessation success may be associated with less risk taking in the face of stress.

Introduction: Nicotine and tobacco smoking administration have demonstrated antinociceptive effects that are mediated by the nicotinic acetylcholine receptor containing the beta2* subunit (beta(2)*-nAChR). In this study, we examined the relationship between beta(2)*-nAChR availability and nociception during acute withdrawal in human tobacco smokers using [(123)I]5-IA-85380 ([(123)I]5-IA) and single photon emission computed tomography (SPECT) brain imaging., Methods: Tobacco smokers (n = 24, aged 34 +/- 11 years) participated in the cold pressor task during acute withdrawal (up to 3 hr) and a second cold pressor task following 7-13 days of smoking abstinence on the day they were imaged with [(123)I]5-IA SPECT. The cold pressor task is used to measure pain sensitivity (when subjects first feel pain) and pain tolerance (when subjects cannot withstand pain)., Results: Following 7-13 days of tobacco smoking abstinence, increased pain sensitivity, for example, shorter time to first feel pain, was significantly associated with higher beta(2)*-nAChR availability in the thalamus (r = -.43), parietal (r = -.50), frontal (r = -.55), anterior cingulate (r = -.44), temporal (r = -.43), and occipital (r = -.48) cortices. The percent change in pain sensitivity from the first to second cold pressor task was significantly correlated with beta(2)*-nAChR availability in the thalamus (r = -.57), cerebellum (r = -.50), striatum (r = -.057), parietal (r = -.46), anterior cingulate (r = -.48), temporal (r = -.55), and occipital (r = -.57) cortices. Similar associations were not observed with pain tolerance., Discussion: This suggests that beta(2)*-nAChRs play a role in pain sensitivity but not pain tolerance during tobacco smoking withdrawal. If individuals are more likely to relapse in response to painful stimuli, lower beta(2)*-nAChR availability during acute abstinence may be protective.

Introduction: Given the prevalence of alcohol use among adolescents and its negative consequences, it is important to learn more about correlates of alcohol-related problems in this population. Cigarette smoking appears to be associated with alcohol-related problems in adolescents. The purpose of this study was to assess cigarettes smoked per day and nicotine dependence (ND) severity as predictors of alcohol-related problems in cross-sectional models, using data from a smoking cessation clinical trial for adolescents., Method: Data obtained at intake were used to assess smoking-related variables as cross-sectional predictors of alcohol-related problems in models along with drinks per week and key demographics, using hierarchical multiple regression., Results: ND severity, as measured using the modified Fagerström Tolerance Questionnaire, significantly predicted alcohol-related problems, both when this score included and did not include an item concerning cigarettes smoked per day. A separate continuous item capturing cigarettes per day did not predict alcohol-related problems., Discussion: ND severity predicted alcohol-related problems in cross-sectional regression models, holding constant alcohol consumption and key demographics. This suggests that ND severity may be a clinical indicator of alcohol-related problems among adolescent smokers. To our knowledge, this is the first analysis of associations between smoking and alcohol involvement in a sample of adolescent smokers participating in a clinical trial.

Little is known about the impact of alcohol involvement on smoking cessation relapse or possible mechanisms for these associations. We addressed these issues using data from a randomized clinical trial of two types of framed messages (gain vs. loss) in conjunction with open label sustained-release (SR) bupropion (Toll et al., 2007) (N = 249). Participants were categorized according to whether or not they were diagnosed with a lifetime alcohol use disorder (AUD; i.e., current or past alcohol abuse or past alcohol dependence) and according to three levels of alcohol use: abstinence, moderate, or hazardous use. Alcohol use categories were established for drinking at baseline, during the 6-week treatment period and through 12 weeks post-quit. There were few significant differences by baseline alcohol use level or AUD history for a series of predictors of smoking cessation failure (e.g., depressive symptoms). During treatment and follow-up, the probability of any smoking on heavy drinking days was significantly higher than the probability of smoking on moderate drinking or abstinent days. AUD history did not predict smoking cessation relapse in any analysis, nor were any alcohol usexAUD history interactions significant. Moderate alcohol users and, to a lesser extent, abstainers from alcohol at baseline were less likely than hazardous drinkers to have relapsed at 12 weeks post-quit. Based on these findings, it appears that risk of any smoking and of relapse was associated primarily with heavy drinking days and a hazardous pattern of use respectively, rather than with moderate drinking.

Contingency management (CM) is a powerful behavioral intervention shown to reduce the use of a variety of substances including tobacco. Use of CM techniques for smoking cessation has been restricted by the use of multiple daily measurements of breath CO as the objective indicator to reinforce abstinence. Cotinine, with its longer half-life, may be a better marker. We evaluated the use of urinary cotinine (determined using once-daily semiquantitative immunoassay test strips and verified using quantitative GC/HPLC techniques) as an abstinence indicator in treatment-seeking adult and adolescent smokers participating in a CM-based intervention program. Both techniques of determining urinary cotinine were highly sensitive and moderately specific at detecting abstinence, and they were highly concordant. However, specificity was somewhat lower during the first few days of a quit attempt and improved over time. The results were similar in adults and adolescent smokers, and suggest that during the first few days of a quit attempt it would be advisable to continue to use daily multiple CO measurements to verify abstinence. However, once abstinence is achieved, once-daily immunoassay test strips could be used for continued monitoring of urinary cotinine levels. Immunoassay testing can identify individuals who relapse to smoking, though this study cannot evaluate whether the strips can identify resumption of abstinence. These results suggest that the use of cotinine as an abstinence indicator, by reducing the number of daily appointments, could significantly enhance the feasibility and utility of CM-based interventions for smoking cessation.

Tobacco withdrawal symptoms have been shown to play a significant role in mediating relapse to smoking in adult smokers; however, few prospective studies have examined the course of tobacco withdrawal symptoms over time and their connection to lapse in adolescent smokers. Withdrawal symptoms were assessed weekly for 4 weeks in a sample of adolescent smokers participating in a pilot cessation intervention. Adolescent smokers experienced an exacerbation in overall withdrawal symptoms, particularly of cravings and restlessness, although symptoms were generally mild. The course of symptoms was different for boys and girls: Girls generally experienced a peak and subsequent decline in symptoms early in the establishment of abstinence, whereas boys experienced a constant level of symptoms that did not decline over the 4 weeks. Finally, withdrawal symptoms experienced on quit day were not related to lapse to smoking during the course of treatment for either boys or girls. These results suggest that although withdrawal symptoms may be uncomfortable, they may not be the most salient to a lapse to smoking for adolescent smokers attempting to quit. These findings have direct implications for the design and implementation of treatment of nicotine dependence in adolescent smokers.

An inability to maintain abstinence is a key indicator of tobacco dependence. Unfortunately, little evidence exists regarding the ability of the major tobacco dependence measures to predict smoking cessation outcome. This paper used data from four placebo-controlled smoking cessation trials and one international epidemiological study to determine relations between cessation success and the Fagerström Test for Nicotine Dependence (FTND), the Heaviness of Smoking Index, the Nicotine Dependence Syndrome Scale, and the Wisconsin Inventory of Smoking Dependence Motives. Results showed that much of the predictive validity of the FTND could be attributed to its first item, time to first cigarette in the morning, and this item had greater validity than any other single measure. Thus the time-to-first-cigarette item appears to tap a pattern of heavy, uninterrupted, and automatic smoking and may be a good single-item measure of nicotine dependence.

We examined the relationship between self-reported in utero tobacco exposure and gender on smoking initiation, progression of cigarette use (i.e., telescoping), and current levels of nicotine dependence in adult treatment-seeking smokers. Subjects (N = 298) who reported "yes" (28% of the original sample) or "no" (50% of the original sample) to in utero tobacco exposure were included in the analyses. Telescoping was calculated as the difference between the age respondents smoked their "first full cigarette" and the age when they started smoking daily. Females who reported being exposed in utero transitioned from initial to daily cigarette use more rapidly than females not exposed. The opposite effect was found for males, which may be related to our finding that in utero exposure lowered the age of cigarette experimentation in exposed compared with unexposed males. Measures of current cigarette use and dependence (i.e., Fagerström Test for Nicotine Dependence, prior withdrawal, number of past year quit attempts) were significantly associated with reported in utero exposure, gender, or interactions of exposure and gender. In utero tobacco exposure may accelerate the progression from experimentation to daily use in girls, result in early tobacco experimentation among boys, and produce higher levels of nicotine dependence among adult smokers.

Different vulnerabilities are launched or play a more active role at different developmental stages and different ages. Furthermore, the interplay between developmental and biological, psychosocial, and environmental vulnerabilities is expected to differ across stages of smoking. This article focuses on the intersection of vulnerability associated with adolescence with tobacco-use vulnerability resulting from biological, psychological, and environmental characteristics of an adolescent. Recommendations include the following: (a) Effectively treat childhood and adolescent behavioral and emotional disorders that place adolescents at risk; (b) target programs toward specific high-risk subgroups; (c) incorporate training in self-control, affect regulation, and healthy coping strategies into educational programs and extracurricular activities; (d) encourage youth to develop healthy sources of success and satisfaction; (e) encourage communities and states to launch environmental, policy, and regulatory initiatives to protect youth from tobacco; (f) consider bold initiatives that will require fundamental changes in public attitudes, including monetary rewards for nonsmoking, heightened penalties for facilitating and engaging in underage smoking, and government subsidies for substitute pharmacological agents.

The complexity of public health problems, including the problem of tobacco use behaviors, calls for formal efforts to train transdisciplinary scientists. These scientists can approach problems by using new conceptual frameworks and methodological tools that integrate different disciplinary perspectives. Transdisciplinary training focuses on developing strong scientists with superb core skills while protecting against creating scientists who are "jack of all trades, master of none." Transdisciplinary training is relatively new, with no accepted training model in place. In this paper, we provide a general framework for transdisciplinary training at the advanced graduate and postgraduate levels, with particular reference to tobacco use behaviors. We identify the core attitude, knowledge, and skills competencies that are essential to conducting tobacco use research with a transdisciplinary approach. We outline the structural components of transdisciplinary training that allow for the development of the competencies and discuss what facilitates the transdisciplinary training process. We also discuss the numerous challenges and obstacles to transdisciplinary training. These include the readiness of early-career trainees to undergo transdisciplinary training, professional development risks taken by trainees, administrative and budgetary obstacles inherent in traditional academic institutional structures, and the limited opportunities established scientists have for transitioning their research programs in a transdisciplinary direction. If these obstacles can be overcome, the potential exists for a new generation of transdisciplinary scientists to be trained and be well positioned to make important and unique advances in our understanding of tobacco use and other public health problems.

This preliminary study evaluated the potential efficacy of 50 mg of opioid antagonist naltrexone or placebo in combination with nicotine replacement therapy for smoking cessation, in a small sample of 32 smokers using one to one and a half packs of cigarettes per day. Addition of naltrexone resulted in an increase in continuous abstinence rates (9/16 for naltrexone vs. 5/16 for placebo). Naltrexone reduced the likelihood of relapse among participants who smoked during the first week of treatment, reduced desire to smoke, and prevented weight gain following smoking cessation. These preliminary results suggest that naltrexone augmentation of nicotine patch therapy using procedures designed to optimize the concurrent use of these two medications may be beneficial for smoking cessation.