Search

There is considerable interest in using propensity score (PS) statistical techniques to address questions of causal inference in psychological research. Many PS techniques exist, yet few guidelines are available to aid applied researchers in their understanding, use, and evaluation. In this study, the authors give an overview of available techniques for PS estimation and PS application. They also provide a way to help compare PS techniques, using the resulting measured covariate balance as the criterion for selecting between techniques. The empirical example for this study involves the potential causal relationship linking early-onset cannabis problems and subsequent negative mental health outcomes and uses data from a prospective cohort study. PS techniques are described and evaluated on the basis of their ability to balance the distributions of measured potentially confounding covariates for individuals with and without early-onset cannabis problems. This article identifies the PS techniques that yield good statistical balance of the chosen measured covariates within the context of this particular research question and cohort. (Contains 2 figures and 2 tables.)

Introduction: A mosaic of evidence links risk perceptions with drug use in adolescence, including population summaries to guide public health campaigns, as well as subject-specific estimates on preventing an adolescent's drug use by manipulating that individual's prior risk perceptions. We re-visit these issues with a public health perspective, asking whether population-level cannabis risk perceptions of school-attending adolescents at one grade level might predict cannabis use prevalence two and four grade levels later.Methods: From 1991 to 2014, each year's United States "Monitoring the Future" (MTF) study population included 8th-, 10th-, & 12th-graders. Two and four years later, statistically independent school samples of the same cohorts were drawn and assessed (n ~ 16,000/year). Population-level modeling estimated cannabis use prevalence at time "t" (12th-grade) regressed on that same cohort's cannabis risk perceptions as had been measured at time "t-4" (8th-grade) and time "t-2" (10th-grade).Results: Higher cannabis risk perception levels for 10th-graders predict lower cannabis use prevalence when 10th-graders have become 12th-graders (β̂=-0.12), and higher cannabis risk perception levels of 8th-graders predict lower cannabis prevalence when 8th-graders have become 10th-graders (β̂=-0.27); p-values < 0.05. Across four-year spans, the prediction is null (p-value = 0.619).Conclusions: This within-cohort across-grade population-level prediction prompts questions for drug prevention specialists, including "Would a relatively small upward shift in a local area population's appraisal of risk perceptions be followed, two years later, by reduced population prevalence of cannabis use?" Future randomized trial designs, health education, or prevention efforts focused on altering early adolescent cannabis risk perceptions might provide the most convincing and definitive evidence. [ABSTRACT FROM AUTHOR]

This article proposes a new type of latent class analysis, joint latent class analysis (JLCA), which provides a set of principles for the systematic identification of the subsets of joint patterns for multiple discrete latent variables. Inferences about the parameters are obtained by a hybrid method of expectation-maximization and Newton–Raphson algorithms. We apply JLCA in an investigation of adolescent violent behavior and drug-using behaviors. The data are from 4,957 male high-school students who participated in the Youth Risk Behavior Surveillance System in 2015. The JLCA approach identifies the different joint patterns of 4 latent variables: violent behavior, alcohol consumption, tobacco cigarette smoking, and other drug use. The JLCA uncovers 4 common violent behaviors and 3 representative behavioral patterns for each of 3 other latent variables. In addition, the JLCA supports 3 common joint classes, representing the most probable simultaneous patterns for being violent and being a drug user among adolescent males. [ABSTRACT FROM AUTHOR]

Abstract: Background: A recent research focus is a set of hypothesized adult-onset mental health disturbances possibly due to early-onset cannabis use (EOCU, onset <18years). We seek to estimate the suspected EOCU-associated excess odds of experiencing an incident depression spell during adulthood, with comparisons to never cannabis smokers and those with delayed cannabis onset (i.e., not starting to smoke cannabis until adulthood). Methods: The National Surveys on Drug Use and Health (NSDUH) assess non-institutionalized community-dwelling residents of the United States after probability sampling each year. In aggregate, the NSDUH analytical sample included 173,775 adult participants from survey years 2005–2009 (74–76% of designated respondents). Standardized computer-assisted interviews collected information on background determinants, age of first cannabis use, and depression spell onset. Logistic regression was used to estimate EOCU-depression spell associations in the form of odds ratios, with statistical adjustment for sex, age, race/ethnicity, years of cannabis involvement, tobacco cigarette onset, and alcohol onset. Results: About 1 in 10 experienced a depression spell during adulthood, and both early-onset and adult-onset cannabis smokers had a modest excess odds of a depression spell compared to never cannabis smokers, even with covariate adjustment (OR=1.7 and 1.8, respectively; both p<0.001). Estimates for early- and adult-onset cannabis smokers did not statistically differ from one another. Limitations: Shared diathesis that might influence both EOCU and adult-onset depression spell is controlled no more than partially, as will be true until essentially all known early-life shared vulnerabilities are illuminated. Conclusion: Cannabis smoking initiated at any age signals a modest increased risk of a spell of depression in adulthood, even when adjusted for suspected confounding variables studied here. Delaying cannabis onset until adulthood does not appear to diminish the cannabis-associated risk. [Copyright &y& Elsevier]

Copyright of Substance Use & Misuse is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Objectives: Models of drug use etiology and prevention require precise information concerning the expression of population-based risk factors across the continuum of drug use. However, the majority of previous epidemiologic research on this topic has not addressed transitions between specific drug stages. The present investigation examined the sociodemographic predictors of progression across six stages of drug use in the National Comorbidity Survey Replication (NCS-R), a nationally representative household survey of the U.S. population conducted between February, 2001 and April, 2003. Methods: Lifetime history of opportunity to use illicit substances, initial drug use, and DSM-IV drug use disorders were collected using in-person structured diagnostic interviews. Results: The median age of first opportunity to use drugs as well as drug use, abuse and dependence each occurred prior to age 20, while the median remission from abuse and dependence occurred at 26 and 30 years, respectively. Most sociodemographic variables, in particular sex and ethnicity, demonstrated highly differential associations with transitions depending on the stage examined. Conclusions: The findings may partially explain the effectiveness of strategies designed to reduce drug use, abuse and dependence, and indicate that increased correspondence is needed between available epidemiologic data and existing models of etiology or prevention. [Copyright &y& Elsevier]

Social role impairment and other forms of maladaptation are referenced explicitly in the case definitions for the drug use disorders within DSM-IV-TR, but there is continuing debate about whether and how to include these manifestations of ‘clinical significance’ in diagnostic criteria and assessment protocols. When a ‘gated’ approach (based on impairment or other maladaptation) has been taken during recent large scale psychiatric surveys with coverage of drug dependence (e.g. to reduce participant fatigue or burden), the net effect may include (a) a reduced number of identified cases, and (b) biases in the estimates of association linked to the occurrence of drug dependence. In this report focused on alcohol dependence, we probe these issues, making use of data from the cross-sectional US National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a household survey with 44,093 adult participants. NESARC alcohol dependence assessments were ‘ungated’, but allowed simulation of a ‘gated’ approach; the end result was a robust decrement in the estimated prevalence of this condition. Nonetheless, patterns of association linking suspected background characteristics to prevalence of alcohol dependence were not appreciably different when the gated and ungated estimates were contrasted. In summary, there are reasons to take the ungated approach in detailed research on alcohol use and dependence. Nevertheless, in panoramic mental health surveys, the inefficiency of an ungated approach must be balanced against the anticipated yield of cases who have experienced alcohol dependence without alcohol related social role impairments or other maladaptation, particularly when the dependence syndromes without these consequences are sometimes thought to lack clinical significance. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The present study uses latent class methods and multiple regression to shed light on hypothesized cocaine dependence syndromes experienced by community residents, who initiated cocaine use within 24 months of survey assessment, and explores possible variation in risk. Identified within public use data files from the United States National Household Surveys on Drug Abuse (NHSDA), and with assessments completed between 1995 and 1998, the study sample consists of 927 recent-onset cocaine users, defined as having initiated cocaine use no more than 24 months prior to assessment (approximate median elapsed time since onset of use ∼12–13 months). The NHSDA included items to assess seven clinical features often associated with cocaine dependence, which were used in latent class modeling. Empirically derived latent classes, in conjunction with prior theory, tend to support a three-class solution, according to which 4% of recent-onset users are members of a class that resembles the DSM-IV cocaine dependence syndrome (mean: 5.4 clinical features (CF)); 16% might be in a cocaine dependence prodrome (mean: 2.4 CF); 80% of recent-onset cocaine users had few or no clinical features (mean<1 CF). Results from latent class regressions indicate that susceptibility to rapid transition from first cocaine use to onset of the LCA-assigned cocaine dependence syndrome might depend upon whether the user starts smoking crack-cocaine and, independently, age at first cocaine use.Neuropsychopharmacology (2006) 31, 2055–2064. doi:10.1038/sj.npp.1301037; published online 8 February 2006 [ABSTRACT FROM AUTHOR]

In this paper, we present new estimates for the risk of becoming cocaine dependent within 24 months after first use of the drug, and study subgroup variation in this risk. The study estimates are based on the National Household Survey on Drug Abuse conducted during 2000-2001, with a representative sample of US residents aged 12 years and older (n = 114241). A total of 1081 respondents were found to have used cocaine for the first time within 24 months prior to assessment. Between 5 and 6% of these recent-onset users had become cocaine dependent since onset of use. Excess risk of recent cocaine dependence soon after onset of cocaine use was found for female subjects, young adults aged 21-25 years, and non-Hispanic Black/African-Americans. Use of crack-cocaine and taking cocaine by injection were associated with having become cocaine dependent soon after onset of use. These epidemiologic findings help to quantify the continuing public health burden associated with new onsets of cocaine use in the 21st century. [ABSTRACT FROM AUTHOR]

The epidemiologic case-crossover method is a powerful tool for research on suspected hazards of illegal drug use, the advantage being a subject-as-own-control approach that constrains stable individual-level susceptibility traits. here, we use the case-crossover method to estimate the magnitude of excess occurrence of panic attacks during months of cocaine use vs. months of no cocaine use, motivated by a prior estimate that cocaine users have three-fold excess risk of panic attack. The self report data on cocaine and panic are from assessments of a nationally representative sample of 1071 recent panic cases age 18 years or older identified as part of the National household Surveys on Drug Abuse conducted in the United States during 1994 1997. Based on case-crossover estimates, cocaine use is associated with a three- to- four-fold excess occurrence of panic attack (estimated relative risk (RR) = 3.3, p = 0.049; 95% confidence interval: 1.0, 13.7). Year-by-yeas; the RR estimates from four independent yearly replicates (1994 1997) are 5.0, 2.0, 3.0, and 3.0. While there are several important limitations, this study adds new evidence about a previously reported suspected causal association linking cocaine use to occurrence of panic attacks, and illustrates advantages of the epidemiologic case-crossover approach and new directions in research on hazards of illegal drug use. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate suspected behavioral autarcesis. Autarcesis refers to a mechanism of non-specific shielding from or immunity to infection or disease. Here, suspecting that some facets of the adolescent behavioral repertoire (ABR) might shield youths from early drug involvement, we studied recent-onset occurrence of first chances to try a drug and first actual drug use, expressed as a function of five observed ABR dimensions: religious, socializing, sports-related, gender socialization, and home-based activities. Nationally representative samples of school-attending youths were drawn in Panama, the five Spanish heritage countries of Central America and the Dominican Republic ( n = 12 797). Drug involvement and ABR were assessed via anonymous self-administered questionnaires. A religious activity dimension and a separate sports dimension were associated inversely with recent onset of adolescent drug experiences, and a socializing activity dimension was related to an increased occurrence of these experiences. For example, for each unit increase of the religious activity dimension of the ABR, there was an associated reduced occurrence of the first chance to try tobacco (OR = 0.75, 95% CI: 0.63–0.90, P = 0.002). Adolescents at higher levels of sports activities and home-based activities were less likely to experience recent-onset actual use of marijuana (OR = 0.45, 95% CI: 0.30–0.67, P < 0.001; OR = 0.56, 95% CI: 0.32–0.99, P = 0.048, respectively). The study evidence lends some support for behavioral autarcesis. Manipulation of selected ABR dimensions might help prevent or reduce adolescent drug involvement, enhancing autarcesis as a protective mechanism. [ABSTRACT FROM AUTHOR]

To investigate the role of religiosity in the earliest stages of drug involvement, the authors studied recent-onset occurrence of first chances to try a drug and first actual drug use, expressed as a function of religious practice behaviors, levels of religious devotion, and religious affiliation. Based upon standardized questionnaire assessments of nationally representative samples of school-attending youths drawn in Panama, the five Spanish heritage countries of Central America, and the Dominican Republic (n = 12,797), the 1999–2000 study estimates indicate that higher levels of religious practice are inversely associated with the earliest stages of tobacco and cannabis experiences (i.e., the first chance to try and the first actual use) but not so for alcohol. To illustrate, for each unit increase in levels of religious practice behaviors, there was an associated reduced occurrence of the first chance to try tobacco (odds ratio = 0.76, 95% confidence interval: 0.62, 0.94). Occurrence of first actual use of tobacco and cannabis was not associated with levels of religious practice behaviors among youths exposed to the opportunity to try these drugs. As such, these behaviors apparently have not strengthened resistance. Rather, autarcesis may be at work, functioning to shield youths from drug exposure opportunities. [ABSTRACT FROM AUTHOR]

Rationale. To estimate the risk of experiencing clinical features of cocaine dependence within 1–2 years of starting cocaine use, and to examine whether crack smoking might increase this risk. Methods. A national sample of recent-onset cocaine users was identified within public data files of the National Household Surveys on Drug Abuse (NHSDA) for the years 1995 through 1998. The sample included 572 recent-onset users of cocaine HCl powder but not crack, and 190 recent-onset users of crack, some of whom had also started use of cocaine powder no more than 23 months prior to assessment. A separate group of 93 recent-onset crack users was identified; this comparison group had started using cocaine HCl powder 2+ years before assessment. Cocaine dependence was assessed via seven standardized questions about clinical features experienced within 12 months of assessment, such as feeling unable to cut down. Multivariate response regressions were used to evaluate crack-associated excess risk and clinical profiles of cocaine dependence. Results. Among persons who had recently started to use cocaine HCl powder but not crack cocaine, about 5–12% experienced clinical features of cocaine dependence. Most clinical features occurred 2–3 times more often among crack smoking users as compared to those using powder only, even with statistical adjustment for frequency of cocaine use (P<0.01). This crack-associated excess risk is more prominent for several clinical features of cocaine dependence, including tolerance associated with cocaine use and narrowed behavioral repertoire attributed to cocaine use. Conclusions. This new epidemiological evidence suggests that crack-smoking may increase risk of cocaine dependence once cocaine use starts, but we cannot rule out the possibility that crack users start out with a greater susceptibility to become cocaine dependent. [ABSTRACT FROM AUTHOR]

Copyright of Substance Use & Misuse is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Published epidemiologic survey statistics do not allow direct cross-national comparison of drug dependence in the US and the UK, primarily because of a lack of uniformity across case definitions and methods of case ascertainment. Aims: The current study sought to re-estimate these prevalence values after calibration of case definitions (i. e., imposing methodological constraints to unify case definitions), to identify suspected determinants, and also to investigate symptom profiles among active cases. Method: Analyses of data from the US National Household Survey on Drug Abuse and the UK Survey of Psychiatric Morbidity were conducted. Prevalence of active drug dependence symptoms was estimated. Logistic regression analysis was used to estimate the magnitude of the association between suspected socio-demographic variables and drug dependence. Results: The prevalence of drug dependence was an estimated 1.4 % in the US and 0.5 % in the UK. This difference was somewhat attenuated when the effect of living in an urban setting was controlled. Symptom profiles among active cases were very similar. In both countries, being male, non-married, of a low socio-economic status (SES), and living in an urban setting were associated with an increased occurrence of drug dependence. Conclusion: There are US-UK differences in prevalence of active drug dependence beyond what available statistics imply and some of this difference can be explained by variations associated with living in urban and rural conditions. [ABSTRACT FROM AUTHOR]

Copyright of Substance Use & Misuse is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Drawing upon an “exposure opportunity” concept described by Wade Hampton Frost, the authors studied two mechanisms to help account for prior observations about the “stepping-stone” or “gateway” sequences that link the use of alcohol, tobacco, marijuana, and cocaine. Data were obtained from four nationally representative and independent cross-sectional samples of US household residents (n = 44,624 persons aged 12–25 years). Data were gathered using standardized self-report methods and were analyzed via survival methods. Results indicated that users of tobacco and alcohol were more likely than nonusers to have an opportunity to try marijuana and were more likely to actually use marijuana once a marijuana opportunity had occurred. Opportunity to use cocaine was associated with prior marijuana smoking. Among young people with a cocaine opportunity, those who had used marijuana were more likely to use cocaine than were those with no history of marijuana use. The observed associations did not seem to arise solely as a result of young drug users' seeking out opportunities to use drugs. Applying Frost's epidemiologic concept of exposure opportunity, the authors offer new epidemiologic evidence on the sequences that link earlier use of alcohol and tobacco to later illegal drug involvement. [ABSTRACT FROM PUBLISHER]

Recent studies in the United States suggest that male-female differences in the prevalence of drug use may result from sex differences in opportunities to use drugs rather than from differences in the likelihood of making a transition into drug use once an opportunity has occurred. That is, men have more opportunities to try drugs, but women appear to be just as likely as men to initiate drug use when given the opportunity to do so. This paper examines whether this general observation holds for subgroups defined by age or birth cohort, race/ethnicity, geographic region, and urban status. We analyzed data from the 1991, 1992, and 1993 National Household Surveys on Drug Abuse. We found general consistency across the subgroups studied. Males were more likely than females to have opportunities to use drugs, but the sexes were equally likely to make a transition into drug use once an opportunity had occurred to try a drug. The implications of this evidence are discussed in relation to the epidemiology and prevention of drug use and with respect to future research on sex and gender differences in drug involvement. [ABSTRACT FROM AUTHOR]

Examines the association between school dropout and injecting drug use among young White non-Hispanic American adults. Use of the data from the National Household Survey on Drug Abuse; Utilization of conditional logistic regression; Comparison of potential for injecting drug use among high school dropouts than graduates.

This study examined the prevalence of drug use in a nationally representative sample of 1989 recipients and 6840 nonrecipients of four welfare programs. Data from the 1995 National Household Survey on Drug Abuse (NHSDA) were analyzed using the conditional form of multiple logistic regression with matching of respondents on neighborhood of residence. Weighted proportions and variances accounting for the complex sample design of the NHSDA survey were estimated using the Taylor series linearization method. The results indicate that drug use is 50% more common in households with welfare recipients than in nonwelfare households. Programs making welfare eligibility contingent on the recipient working toward a drug-free lifestyle are worth examining, although a vigilant eye must be kept on the potential unintended consequences. [ABSTRACT FROM AUTHOR]

Aims. To examine whether male-female differences in rates of drug use could be traced back to differences in rates of exposure to initial opportunities to try drugs, rather than to sex differences in the probability of making a transition to use, once opportunity has occurred. Design. Cross-sectional sample survey research with nationally representative samples and retrospective assessments. Setting. United States, 1979-94. Participants. Respondents were 131 226 residents aged 12 years and older, recruited for the National Household Surveys on Drug Abuse by multi-stage probability sampling at nine time points. Measurements. Estimated proportion of males and females with an opportunity to use marijuana, cocaine, hallucinogens and heroin; proportions reporting use among those having an opportunity to use each drug; proportion making a "rapid transition" from initial opportunity to initial use. Findings. For each survey year, males were more likely than females to have an initial opportunity to use drugs. However, few male-female differences were observed in the probability of making a transition into drug use, once an opportunity had occurred. Conclusions. Previously documented male excess in rates of drug use may be due to greater male exposure to opportunities to try drugs, rather than to greater chance of progressing from initial opportunity to actual use. This suggestes that sex differences in drug involvement emerge early in the process. Implications of these findings are discussed in relation to the epidemiology and prevention of drug use, and future research on sex differences in drug involvement. [ABSTRACT FROM AUTHOR]

Objectives. Based on an epidemiologic field survey of community households in Puerto Rico, this study estimates the frequency of illicit drug use and clinically defined drug abuse and/or dependence syndromes. Results are compared with those from surveys on the United States mainland. Suspected risk factors are studied as well, with a special focus on childhood misbehavior. Methods. Trained lay interviewers administered a Spanish Diagnostic Interview Schedule to 912 respondents aged 17 to 68 years who were selected by multistage probability sampling of island households. Results. An estimated 8.2% of the population had a history of illicit drug use and 1.2% qualified for a standardized lifetime diagnosis of drug abuse, dependence, or both. An estimated 18.4% of the male drug users and 7.7% of the female drug users met criteria for drug abuse and/or dependence. A history of drug use was related to the diagnoses of alcohol abuse and/or dependence and antisocial personality, but few persons who had used illicit drugs at least once in their lifetime reported a history of receiving treatment for alcohol, drug, or mental health problems. Conclusions. The data were consistent with a suspected association between level of childhood misbehavior and occurrence of illicit drug use, even after statistical control for potentially confounding variables. [ABSTRACT FROM AUTHOR]

Abstract: This study examined the hypothesized predictive association between illicit drug use and the onset of prescribed psychotherapeutic medicine use. The effect of psychiatric symptoms on this relationship was also explored. Data were gathered retrospectively, through standardized household interviews conducted in 1981 for the Baltimore site of the National Institute of Mental Health Epidemiologic Catchment Area Program. For this analysis, the sample was restricted to 1,716 respondents ages 18-44 at the time of interview, drawn by probability sampling area household residents of all adult ages. Using Cox proportional hazards models, the onset of psychotherapeutic medicine use was modeled as a function of illicit drug use and psychiatric symptoms, both defined as time-dependent covariates. Newly observed in this analysis was an independent association of illicit drug use with psychotherapeutic medicine use, which was unexplained by psychiatric symptoms (relative hazard = 2.61, 95% confidence interval (CI) = 2.15, 3.18). Adjustment for age of onset of alcohol intoxication did not alter the impression that illicit drug users were more likely to initiate use of prescribed psychotherapeutic medicines (relative hazard = 2.52, 95% CI = 2.02, 3.11). (Am J Public Health 1990;80:61-65.) [ABSTRACT FROM AUTHOR]

Examines whether parental supervision and monitoring in middle childhood might have a sustained impact on risk of drug use later in childhood and adolescence. Method of study; Drug use at earlier ages of children in the lowest quartile of parent monitoring; Supervision and monitoring in middle childhood by parents and delay or prevention of drug use among youths.

Looks at a study which attempts to probe the meaning of reported racial and ethnic differences in the prevalence of crack cocaine smoking and to estimate the degree to which crack cocaine smoking is associated with personal factors specific to race/ethnicity. Finding that crack use does not strongly depend on race-specific (eg biologic) personal factors; Reanalysis of data from the 1988 National Household Survey of Drug Abuse; Details.

This paper reviews issues related to the measurement of drug use and other behaviors in studies of human immunodeficiency virus (HIV) infection in intravenous drug users. These issues include: (1) choice of variables, (2) study design, (3) time frame of measurement, (4) categories of measurement, (5) interviewer effects, and (6) validity of measurement. Difficulties and approaches for measuring drug use and other intimate behaviors in intravenous drug users are discussed. Attempts to come to terms with these measurement issues in the context of HIV infection in intravenous drug users should lead to the further development of methods for use in the general context of drug abuse research. [ABSTRACT FROM AUTHOR]

Presents a study which focused on inhalant drug use among adolescents in the United States. Epidemiology of inhalant drug use; Examination of age, sex, and race or ethnicity variations in the occurrence of inhalant use; Transitory nature of inhalant use among adolescents; Analysis of data collected from the National Household Survey on Drug Abuse from 1990 through 1995; Results of this study.

This study examined the extent to which self-report of human immunodeficiency virus (HIV) risk behaviors might depend upon socially desirable response tendencies, and whether socially desirable responding might serve as a confounding variable in the study of risk behaviors and HIV serostatus. The subjects were 2885 intravenous drug users participating in the ALIVE study in Baltimore, Maryland. Participants completed an interview and were tested for HIV serostatus. The interview covered HIV risk behaviors, and included established scales to measure 'self-deception' and 'impression management' two separate dimensions of socially desirable responding. Seven items for each scale were scored true/false, with a summary score used for analysis. Scores on self-deception and impression management were inversely related to self-reports of sharing injection equipment, injecting at shooting galleries, and injecting more than once a day. Neither self-deception nor impression management was associated with cocaine use. Self-reported receptive anal intercourse was associated inversely with self-deception but not with impression management. HIV serostatus was not associated with social desirability, and statistically controlling for social desirability had a negligible impact on the magnitude of associations between risk behaviors and HIV serostatus. The results indicate that measures of social desirability may be used to ascertain sensitive areas of inquiry in interviews of intravenous drug users. [ABSTRACT FROM AUTHOR]

Abstract: Background: A specific facet of parental monitoring is known as ‘limiting time with friends’ (LTF). Here, we aim to learn whether LTF-associated differences in adolescent risk of starting to use tobacco, alcohol, and other drugs now might be as large as observed male–female risk differences. Methods: Data are from the US National Surveys on Drug Use and Health, with annual large scale nationally representative samples of community-dwelling civilian age 12 years and older, conducted 2002–2009. Focus is on 12–17-year-old participants, assessed via computerized self-interviews. Risk differences are estimated for all 12–17 year olds, males and females separately, and in relation to the LTF facet of parenting. Results: Contingency table analyses disclose a female excess risk of initiating use of tobacco, alcohol, cocaine, opioids, and EMIRD, with male–female risk differences ranging from 0.1% (cocaine) to 1.6% (alcohol). LTF-associated risk differences were of similar magnitude for young people whose parents ‘always’ limit time with friends versus those with parents who are more relaxed about the LTF facet of parenting [e.g., RD=0.4% (cocaine); 1.5% (alcohol)]. Conclusions: Not just for tobacco, but also for other drugs, there now is female excess risk of extra-medical drug use. Drug-by-drug, observed LTF-associated risk differences are about the same size as the female excess risk. This evidence provides a rationale to sustain focus on the LTF facet of parenting if the goal is to enhance prevention of precocious drug involvement and to delay its onset until later in the adolescent or adult years. [Copyright &y& Elsevier]

The article comments on the paper "B. Cannabis and schizophrenia: model projections of the impact of the rise in cannabis use on historical and future trends in schizophrenia in England and Wales," by M. Hickman and colleagues. The paper presents estimates from a simulation exercise to project the effect of the use of cannabis on future incidence of schizophrenia. The projections are based upon the assumption that cannabis smoking causes newly incident cases of schizophrenia.

Presents a letter to the editor regarding the concept of behavioral autarcesis published in the August 2004 issue of "Addiction."

Abstract: Analyzing self-report interview data from a multi-site collaborative study of mental disorders in the community, we examined suspected differences between 611 cocaine users and 126 heroin users in relation to indicators of drug dependence. Cocaine users were less likely to report dependence-related problems as compared to heroin users. These epidemiologic sample data underscore concerns about the generalizability of published clinical sample data on self-reported cocaine dependence. [ABSTRACT FROM AUTHOR]

Abstract: In this discussion of contributed papers for the special issue of DAD, the author draws attention to early American laws concerning cannabis and to statements made about the epidemiology of cannabis smoking and other drug use between 1858 and the contemporary scene, with coverage of opium, heroin, tobacco, alcohol, cocaine, kava, and other drugs. He discusses these steppingstone and gateway processes in relation to political environment and in relation to scientific challenges such as uncontrolled confounding. He provides a critique of between-individual research designs, including co-twin and co-sib designs of behavior genetics, as well as imaging research, where uncontrolled confounding often exists. He highlights the epidemiologic case-crossover design and prevention research experiments as potentially valuable approaches in new directions for research on the steppingstone and gateway processes. [Copyright &y& Elsevier]

Abstract: There is substantial evidence that alcohol, tobacco, and cannabis dependence problems surface more quickly when use of these drugs starts before adulthood, but the evidence based on other internationally regulated drugs (e.g., cocaine) is meager. With focus on an interval of up to 24 months following first drug use, we examine drug-specific and age-specific variation in profiles of early-emerging clinical features associated with drug dependence. Based upon the United States National Surveys on Drug Use and Health (NSDUH) conducted in 2000–2002, the risk of experiencing drug dependence problems was robustly greater for adolescent recent-onset users of cocaine, psychostimulant drugs other than cocaine, analgesics, anxiolytic medicines, inhalants drugs, and cannabis, as compared to adult recent-onset users (odds ratio=1.5–4.3, p <0.05). This was not the case for the NSDUH hallucinogens group (e.g., LSD). The adolescent onset associated excess risk was not constant across all clinical features. Our evidence suggests promoting earlier detection and interventions, as well as greater parent and peer awareness of drug dependence clinical features that may develop early among young people who have just started using drugs. [Copyright &y& Elsevier]

Abstract: Background: There is a need for large-scale epidemiological surveys to be (a) faithful to diagnostic specifications and (b) constrain time and participant burden associated with each section of a possibly lengthy interview. Objective: To examine whether one “gating” approach devised for recent large-scale international psychiatric surveys results in a reduced number of identified cases of drug dependence and/or biases in estimated associations with background characteristics. Design and setting: Data from a recently released cross-sectional, nationally representative household survey, the United States National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) were analysed. Participants: Forty-three thousand ninety-three English speaking adults aged 18 years and over. Main outcome measures: Dependence upon cocaine and other illegal drug dependence, defined in two ways: “ungated” and “gated”. “Ungated” dependence included all persons meeting criteria for DSM-IV dependence, without regard for DSM-IV drug abuse clinical features. “Gated” dependence required at least one feature of DSM-IV drug abuse. Results: There was no statistically robust decrement in the estimated prevalence of cocaine or other drug dependence using a “gated” assessment. Patterns of association of cocaine dependence with background characteristics were not appreciably different when the gated and ungated approaches were applied. Conclusions: In panoramic mental health surveys, the inefficiency of an ungated approach must be balanced against the anticipated number of cases of dependence without associated social role impairments or harm. In this study, the reduction in the number of identified cocaine dependence cases appeared to be so small that even in a sample of over 40,000 participants, attenuation in population prevalence would prove difficult to detect. [Copyright &y& Elsevier]

Abstract: In this study, we estimate a hypothesized link from early onset inhalant use to later use of opiates by young adulthood, with data from an epidemiological sample of 2311 first graders who entered an urban mid-Atlantic public school system in 1985 or 1986 (49.8% male; 67.1% ethnic minority), and who were studied longitudinally to young adulthood. An estimated 9% had initiated inhalant use before the age of 14 and at follow-up in young adulthood an estimated 3% (n =66) of the sample had tried opiates at least once. Youth who used inhalants prior to age 14 were twice as likely to initiate opiate use, as compared to those who had never tried (relative risk 2.2; 95% CI=1.4, 3.3). Statistical adjustment for other covariates attenuated but did not dissolve this relationship. These findings help confirm previously reported evidence that the use of inhalants might be an early marker of vulnerability for future involvement with illegal drugs such as heroin, but an exploratory analysis suggests that there may be no direct inhalants–opiate link once a general early onset susceptibility trait is taken into account. [Copyright &y& Elsevier]

The aim of this study is to shed light upon an observed association between the use of marijuana and hallucinogens (e.g. LSD), with a specific focus on the idea that two separate mechanisms might link marijuana use to hallucinogen use: (1) greater hallucinogen exposure opportunity for marijuana users versus nonusers; (2) increased probability of hallucinogen use for marijuana users versus nonusers, once the opportunity to use hallucinogens has occurred. This work is based on a novel analysis of retrospective, self-report data from more than 40 000 young participants in the 1991–1994 National Household Surveys on Drug Abuse (NHSDA), with discrete time survival analysis models. Youths who had used marijuana were substantially more likely than nonusers to have the opportunity to use hallucinogens (estimated unadjusted relative risk, uRR=16.3; 95%. Confidence interval (CI)=14.3–18.6). Once an opportunity to use hallucinogens occurred, marijuana users were more likely than nonusers to initiate hallucinogen use (uRR=12.6; 95% CI=9.0–17.6). This evidence provides a more complete view of interconnections between marijuana use and hallucinogen use, and helps to clarify the pivotal role for drug exposure opportunities. Important next steps will be to understand what accounts for variation in the exposure opportunities experienced by marijuana users, and to understand why some marijuana users do not progress even when they have a chance to do so. [Copyright &y& Elsevier]

Background: Validity of responses in surveys is an important research concern, especially in emerging market economies where surveys in the general population are a novelty, and the level of social control is traditionally higher. The Randomized Response Technique (RRT) can be used as a check on response validity when the study aim is to estimate population prevalence of drug experiences and other socially sensitive and/or illegal behaviors.Aim: To apply RRT and to study potential under-reporting of drug use in a nation-scale, population-based general population survey of alcohol and other drug use.Methods: For this first-ever household survey on addictive substances for the Country of Georgia, we used the multi-stage probability sampling of 18-to-64-year-old household residents of 111 urban and 49 rural areas. During the interviewer-administered assessments, RRT involved pairing of sensitive and non-sensitive questions about drug experiences.Results: Based upon the standard household self-report survey estimate, an estimated 17.3% [95% confidence interval, CI: 15.5%, 19.1%] of Georgian household residents have tried cannabis. The corresponding RRT estimate was 29.9% [95% CI: 24.9%, 34.9%]. The RRT estimates for other drugs such as heroin also were larger than the standard self-report estimates.Discussion and Conclusions: We remain unsure about what is the "true" value for prevalence of using illegal psychotropic drugs in the Republic of Georgia study population. Our RRT results suggest that standard non-RRT approaches might produce 'under-estimates' or at best, highly conservative, lower-end estimates. [ABSTRACT FROM AUTHOR]

Abstract: Background: It is unclear whether the normative sequence of drug use initiation, beginning with tobacco and alcohol, progressing to cannabis and then other illicit drugs, is due to causal effects of specific earlier drug use promoting progression, or to influences of other variables such as drug availability and attitudes. One way to investigate this is to see whether risk of later drug use in the sequence, conditional on use of drugs earlier in the sequence, changes according to time-space variation in use prevalence. We compared patterns and order of initiation of alcohol, tobacco, cannabis, and other illicit drug use across 17 countries with a wide range of drug use prevalence. Method: Analyses used data from World Health Organization (WHO) World Mental Health (WMH) Surveys, a series of parallel community epidemiological surveys using the same instruments and field procedures carried out in 17 countries throughout the world. Results: Initiation of “gateway” substances (i.e. alcohol, tobacco and cannabis) was differentially associated with subsequent onset of other illicit drug use based on background prevalence of gateway substance use. Cross-country differences in substance use prevalence also corresponded to differences in the likelihood of individuals reporting a non-normative sequence of substance initiation. Conclusion: These results suggest the “gateway” pattern at least partially reflects unmeasured common causes rather than causal effects of specific drugs on subsequent use of others. This implies that successful efforts to prevent use of specific “gateway” drugs may not in themselves lead to major reductions in the use of later drugs. [Copyright &y& Elsevier]

Abstract: Background: In epidemiology, it always has been important to study local area patterns of disease occurrence. New methods to quantify local area and household clustering of disease emerged late in the 19th century and were refined during the 20th century. Nonetheless, multi-level models to estimate local area clustering of illegal drug use did not appear until the 1990s, and to date, there is just one study with estimates of local neighbourhood clustering of cannabis use, based on a United States sample. Here, seeking the first replication of that single prior study, we estimate the degree to which cannabis use might cluster within neighbourhoods of New Zealand (NZ), and we also study higher level clustering and suspected individual-level determinants of recent cannabis use. Methods: A national probability community sample (n =12,992) of adults aged 16 years or more with standardized assessment of cannabis use. Alternating logistic regression produced estimates for cannabis clustering. Results: In NZ, use of cannabis was common: 41.6% had ever used it and 13.1% had used it in the past year. There was clustering within the smallest local areas (pairwise odds ratio=1.3–1.5) but not within larger government districts (PWOR=1.02). Age, male sex, ethnicity, education, and marital status were all associated with cannabis use, but did not account for observed clustering. Conclusions: Neighborhood clustering of recent cannabis use has emerged in New Zealand, as in the US. Standard individual-level characteristics explain only some of this clustering. Other explanations must be sought, perhaps including personal networks and local supply. [Copyright &y& Elsevier]

Abstract: In this report from a longitudinal study, the main aim was to evaluate the long-term predictive strength of a novel cartoon-based risk-taking trait assessment, which might prove to have utility in future research on mechanisms leading toward illegal drug involvement. The study population originated as 2311 first-graders entering 19 elementary schools during two successive school years. The assessments started soon after the children entered primary school. The key response variable was participants'' use of cocaine by the time of a young adult assessment. We found that for each standard deviation increase in the risk-taking scale there was a two-fold increase in the risk of becoming a cocaine user by young adulthood (estimated relative risk, RR=1.9; 95% confidence interval, CI=1.3, 2.7). Independently, onset of cannabis use by young adulthood was also predicted by risk-taking scale values, but use of legal drugs (alcohol and tobacco) was not. These long-span associations provide support for new research on very early risk-taking mechanisms that lead toward illegal drug involvement. [Copyright &y& Elsevier]

Abstract: Background: In 1994, epidemiological patterns of extra-medical drug use in the United States were estimated from the National Comorbidity Survey. This paper describes such patterns based upon more recent data from the National Comorbidity Survey Replication (NCS-R). Methods: The NCS-R was a nationally representative face-to-face household survey of 9282 English-speaking respondents, aging 18 years and older, conducted in 2001–2003 using a fully structured diagnostic interview, the WHO Composite International Diagnostic Interview (CIDI) Version 3.0. Results: The estimated cumulative incidence of alcohol use in the NCS-R was 92%; tobacco, 74%; extra-medical use of other psychoactive drugs, 45%; cannabis, 43% and cocaine, 16%. Statistically robust associations existed between all types of drug use and age, sex, income, employment, education, marital status, geography, religious affiliation and religiosity. Very robust birth cohort differences were observed for cocaine, cannabis, and other extra-medical drug use, but not for alcohol or tobacco. Trends in the estimated cumulative incidence of drug use among young people across time suggested clear periods of fluctuating risk. Conclusions: These epidemiological patterns of alcohol, tobacco, and other extra-medical drug use in the United States in the early 21st century provide an update of NCS estimates from roughly 10 years ago, and are consistent with contemporaneous epidemiological studies. New findings on religion and religiosity, and exploratory data on time trends, represent progress in both concepts and methodology for such research. These estimates lead to no firm causal inferences, but contribute to a descriptive epidemiological foundation for future research on drug use and dependence across recent decades, birth cohorts, and population subgroups. [Copyright &y& Elsevier]