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There is substantial evidence for the assumption that particularly heavy cannabis usett is associated with a variety of psychopathologic conditions. Little is known about the relationship between cannabis and anxiety. Prior studies have concluded that cannabis use alone is not sufficient for the development of long-term anxiety, and it has been suggested that cannabis is simply a risk factor that operates in conjunction with other risk factors. One such risk factor may be an individuals' genetic vulnerability. The present study examines the relationship between cannabis use and symptoms of anxiety by taking a developmental molecular-genetic perspective with a focus on a polymorphism involved in the regulation of serotonin. Specifically, we concentrated on changes in cannabis use and symptoms of anxiety over time and differences herein for individuals with and without the short allele of the 5-HTTLPR genotype. Data were from 1424 adolescents over a period of 5 years. We used different statistical analyses to test co-development of cannabis use and symptoms of anxiety throughout adolescence and the possible role of the 5-HTTLPR genotype in this process. Results from different analyses showed that cannabis use is associated with an increase in symptoms of anxiety, but only in carriers of the short allele of the 5-HTTLPR genotype, not in non-carriers. The findings of the present study show first evidence that the links between cannabis use and symptoms of anxiety are conditional on the individuals' genetic make-up., (© 2016 Society for the Study of Addiction.)

Objectives: The present study examined whether the relation of parental solicitation, parental control, and child disclosure with adolescent alcohol and cannabis use is similar for native and non-Western immigrant Dutch adolescents., Design: Questionnaire data from two study-samples were used with a combined sample of 705 adolescents (mean age 16.2 years; 47.2% female; 25.2% non-Western immigrant background)., Results: Native Dutch adolescents reported more weekly alcohol use than immigrant adolescents, while rates of cannabis use by native and immigrant adolescents were similar. Immigrant females reported lower levels of parental solicitation and child disclosure, but higher levels of parental control than native females. There were no differences in the sources of parental knowledge between native and immigrant males. Regression analyses showed no significant interaction effects of parental solicitation, parental control, or child disclosure with ethnic background for both alcohol and cannabis use (all p values > .05)., Conclusion: Despite mean level differences in various factors, we did not find evidence of an interaction effect of the sources of parental knowledge with ethnic background on alcohol and cannabis use. This suggests that theories and prevention strategies focusing on these sources of parental knowledge in relation to substance use can be applicable to both native and immigrant Dutch adolescents.

Introduction: Higher prevalence rates of cannabis abuse/dependence and abuse/dependence criteria in 18-24year old versus older cannabis users and in males versus females might reflect true differences in the prevalence of these disorders across age and gender or, alternatively, they could arise from age- and gender-related measurement bias. To understand differences in endorsement across important subgroups, we examined the influence of age and gender simultaneously on the likelihood of endorsement of the various abuse/dependence criteria., Method: The sample consisted of 1603 adult past year cannabis users participating in the National Epidemiological Survey on Alcohol and Related Conditions (NESARC), a U.S. population study (39.6% aged 18-24; 62.1% male). Past year DSM-IV cannabis abuse/dependence criteria and withdrawal were assessed with the AUDADIS-IV. A restricted factor analysis with latent moderated structures was used to detect measurement bias., Results: Although cannabis abuse and dependence diagnoses and various individual abuse/dependence criteria showed different prevalence rates across younger and older male and female cannabis users, none of the items showed uniform or non-uniform measurement bias with respect to age or gender., Conclusion: The results indicate that, although prevalence rates of cannabis abuse/dependence criteria differ across age and gender, past year abuse/dependence criteria function similarly across these groups. It can thus be concluded that the criteria are applicable to younger and older, as well as male and female, adult cannabis users., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Aims: To examine whether early onset of tobacco or alcohol use, and continued use of tobacco or alcohol in early adolescence, are related to a higher likelihood of developing a cannabis use disorder during adolescence., Design and Setting: Data were used from four consecutive assessment waves of the TRacking Adolescents' Individual Lives Survey (TRAILS), a general Dutch population study. TRAILS is an ongoing longitudinal study that will follow the same group of adolescents from the ages of 10 to 24 years., Participants: The sample consisted of 1108 (58% female) adolescents (mean ages at the four assessment waves are 11.09, 13.56, 16.27 and 19.05 years, respectively), Measurements: Cannabis use disorders were assessed using the Composite International Diagnostic Interview 3.0 (CIDI). Adolescent tobacco and alcohol use were assessed using self-report questionnaires., Findings: Early-onset tobacco use [odds ratio (OR) = 1.82, confidence interval (CI) = 1.05-3.14, P < 0.05], but not early-onset alcohol use (OR = 1.33, CI = 0.84-2.12, P > 0.05), was associated with a higher likelihood of developing a cannabis use disorder. Similarly, adolescents who reported continued use of tobacco (OR = 2.47, CI = 1.02-5.98, P < 0.05), but not continued use of alcohol (OR = 1.71, CI = 0.87-3.38, P > 0.05), were more likely to develop a cannabis use disorder., Conclusions: Early-onset and continued tobacco use appear to predict the development of a cannabis use disorder in adolescence, whereas early onset and continued alcohol use do not., (© 2013 Society for the Study of Addiction.)

Background: Several studies have shown that early cannabis use is correlated with poor educational performance including high school drop-out. The predominant explanation for this relationship is that cannabis use causes disengagement from education. Another explanation is that the association between early cannabis use and educational attainment is not causal, but the result of overlapping risk factors that increase the likelihood of both early cannabis use and disengagement from education. These confounding factors could be of genetic and/or environmental origin., Methods: Here we use data from a large community-based sample of adult twins (N=3337) who completed a comprehensive semi-structured telephone interview. We first apply the classical twin-design to determine whether genetic and/or environmental influences underlie the relationship between early-onset cannabis use (prior to age 18) and early school leaving. Next, with a co-twin control design we investigate whether the relationship between the two variables is more likely due to direct causality or overlapping risk factors., Results: We find a significant phenotypic correlation between early-onset cannabis use and early school leaving (r=0.26), which could be explained by familial influences (of genetic and/or shared environmental origin). The pattern of odds ratios found in the co-twin control design is not consistent with direct causation, but rather suggests that the association is due to shared environmental factors influencing both variables., Conclusion: Our findings suggest that the relationship between early-onset cannabis use and school leaving is due to shared environmental risk factors influencing both the risk of early-onset cannabis use and early school leaving., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Aims: To examine the direction of the longitudinal association between vulnerability for psychosis and cannabis use throughout adolescence., Design: Cross-lagged path analysis was used to identify the temporal order of vulnerability for psychosis and cannabis use, while controlling for gender, family psychopathology, alcohol use and tobacco use., Setting: A large prospective population study of Dutch adolescents [the TRacking Adolescents' Individual Lives Survey (TRAILS) study]., Participants: A total of 2120 adolescents with assessments at (mean) age 13.6, age 16.3 and age 19.1., Measurements: Vulnerability for psychosis at the three assessment points was represented by latent factors derived from scores on three scales of the Youth Self-Report and the Adult Self-Report, i.e. thought problems, social problems and attention problems. Participants self-reported on cannabis use during the past year at all three waves., Findings: Significant associations (r = 0.12-0.23) were observed between psychosis vulnerability and cannabis use at all assessments. Also, cannabis use at age 16 predicted psychosis vulnerability at age 19 (Z = 2.6, P < 0.05). Furthermore, psychosis vulnerability at ages 13 (Z = 2.0, P < 0.05) and 16 (Z = 3.0, P < 0.05) predicted cannabis use at, respectively, ages 16 and 19., Conclusions: Cannabis use predicts psychosis vulnerability in adolescents and vice versa, which suggests that there is a bidirectional causal association between the two., (© 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.)

Background: Both environmental risk and genetic variation is believed to play a role in substance use. A candidate environmental variable is parenting. Recent studies have found support for the idea that the dopamine system affects the susceptibility to environmental influences. In the present study we will examine the interplay between effects of parental monitoring and the presence of the DRD4 7-repeat allele in adolescent lifetime cannabis use and the developmental course of cannabis use., Methods: A total of 311 adolescents participated in a five-wave longitudinal design. First, we conducted logistic regression analyses to examine the prospective associations between parental monitoring, the DRD4 polymorphism, their interaction and lifetime cannabis use. Second, individual growth parameters were calculated for frequency of cannabis use. Linear regression was used to assess the relationship between parental monitoring, the DRD4 polymorphism, their interaction, and the frequency of cannabis use., Results: There were no significant main effects of parental monitoring or the DRD4 polymorphism. However, both analyses showed that over a period of four years, a) when experiencing low levels of parental monitoring, individuals with the 7-repeat allele were more likely to show lifetime cannabis use and a stronger increase in frequency of cannabis use than individuals without this allele; b) when experiencing high levels of parental monitoring, individuals with the 7-repeat allele were less likely to show lifetime cannabis use and they showed a smaller increase in frequency of cannabis use than individuals without the 7-repeat allele., Conclusions: This study shows that carriers of the DRD4 7-repeat allele are disproportionally affected by the negative and positive effects of parental monitoring such that carriers of the DRD4 7-repeat allele, as compared to non-carriers, are more likely to use cannabis when levels of parental monitoring are low, and less likely to use cannabis when parental monitoring levels are high.

Aims: To investigate the relationship of life-time and repeated cannabis use with hypothalamic-pituitary-adrenal (HPA) axis reactivity to social stress in a general population sample of adolescents., Design: Adolescents who reported life-time or repeated cannabis use, life-time or repeated tobacco use and never use of either cannabis or tobacco were compared with respect to their HPA axis reactivity during the Groningen Social Stress Task (GSST), which was based on the Trier Social Stress Task., Setting: A large prospective population study of Dutch adolescents [the TRacking Adolescents' Individual Lives Survey (TRAILS) study]., Participants: A total of 591 adolescents (51% male) who participated in the GSST, which was an additional measurement during the third assessment wave., Measurements: HPA axis stress-reactivity was indexed by four cortisol samples collected before, during and after the GSST. Furthermore, all adolescents in our study completed self-reported questionnaires on life-time and repeated cannabis and tobacco use. Models were adjusted for sex, recent alcohol use, experimental session risk status, socio-economic status, mood and time of the experimental session., Findings: Life-time cannabis users had significantly lower stress-reactivity levels when compared to abstainers [odds ratio (OR) = 0.68, confidence interval (CI) = 0.55-0.85, P < 0.01] and life-time tobacco users (OR = 0.79, CI = 0.64-0.98, P < 0.05). In addition, repeated cannabis users also exhibited lower stress-reactivity levels when compared to life-time ever users of either tobacco or cannabis (OR = 0.74, CI = 0.53-0.98, P < 0.05)., Conclusions: Lower hypothalamic-pituitary-adrenal-axis stress-reactivity in adolescents is related specifically to life-time and repeated cannabis use., (© 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.)

Purpose: There is substantial research linking tobacco and alcohol use to subsequent cannabis use, yet the specificity of this relationship is still under debate. The aim of this study was to examine which substance use model--the gateway hypothesis, the common liability (CL) model and/or the route of administration model--best explains the relationship between early onset of tobacco and alcohol use and subsequent cannabis use initiation., Methods: We used data from 2,113 (51% female) Dutch adolescents who participated in three consecutive assessment waves (mean age: 11.09, 13.56, and 16.27 years, respectively) of the TRacking Adolescents' Individual Lives Survey study. (Pre)adolescent cannabis, tobacco and alcohol use was assessed using the Youth Self-Report and a TRacking Adolescents' Individual Lives Survey developed questionnaire., Results: We found that, during adolescence, early onset of tobacco use does not pose a significantly higher risk of initiating cannabis use than early onset alcohol use. Therefore, we can rule out the route of administration model. Moreover, we found that adolescents who reported early onset comorbid use of both tobacco and alcohol have a higher likelihood to initiate cannabis use than adolescents who have tried either tobacco or alcohol. The gateway hypothesis is not broad enough to explain this finding. Therefore, the CL model best predicts our findings., Conclusion: Future research on adolescent cannabis initiation should focus on testing the robustness of the CL model. Furthermore, identifying adolescents who use both tobacco and alcohol, before the age of 13, may help to curtail the onset of cannabis use., (Copyright © 2011 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Aims: The aim of the present study was to determine the mediating role of affiliation with cannabis-using peers in the pathways from various dimensions of temperament to life-time cannabis use, and to determine if these associations also contributed to the development of regular cannabis use., Methods: Objectives were studied using data from 1300 participants of the Tracking Adolescents' Individual Lives Survey (TRAILS), a large, general population study of Dutch adolescents. We used parent-reports on the Early Adolescent Temperament Questionnaire to assess the dimensions of high-intensity pleasure, shyness, fearfulness, frustration and effortful control at age 10-12 years. By means of self-reports, life-time and regular cannabis use were determined at age 15-18 years, and proportion of substance-using peers was determined at ages 12-15 and 15-18 years. Models were adjusted for age, sex, intelligence and parental cannabis use., Results: High-intensity pleasure [odds ratio (OR) = 1.09, 95% confidence interval (CI) = 1.05-1.13] and effortful control (OR = 0.92, 95% CI = 0.89-0.96) affected the risk for life-time cannabis use through their influence on affiliation with cannabis-using peers. Shyness affected this risk independently from peer cannabis use. Only the pathway from effortful control was associated additionally with the development of regular cannabis use (OR = 0.93, 95% CI = 0.89-0.98)., Conclusions: Peer cannabis use and, to a lesser extent, certain temperamental characteristics affect an adolescent's risk of cannabis use, and should be considered in prevention programmes. We recommend future research to focus upon factors that potentially modify the association between temperament, affiliation with cannabis-using peers and cannabis use.

Objective: To examine externalizing behavior problems and cigarette smoking as predictors of subsequent cannabis use., Method: Dutch adolescents (N = 1,606; 854 girls and 752 boys) from the TRacking Adolescents' Individual Lives Survey (TRAILS) ongoing longitudinal study were examined at baseline (ages 10-12 [T1]) and at two follow-up assessments (ages 12-15 [T2] and 15-18 [T3]). The analysis focused on DSM-IV externalizing behavior (conduct, attention deficit hyperactivity, and oppositional) problems at T1, assessed by the Youth Self Report and the Child Behavior Check List, on self-reported ever smoking at T2, and on cannabis use at T3., Results: All associations of parent-rated externalizing behavior problems with cannabis were mediated by earlier smoking. Considering self-reported problems, none of these associations with cannabis were mediated by smoking, except the influence of self-reported conduct problems in girls. Interestingly, even after adjusting for externalizing problems, earlier smoking independently and consistently predicted cannabis use. The adjusted odds ratios for smoking varied in boys from 4.8 to 5.2 (ever) from 10 to 12 (daily) and from 22 to 23 (early-onset) whereas in girls from 4.9 to 5.0, 5.6 to 6.1, and 27 to 28, respectively (p <.001 for all)., Conclusions: Our findings challenge the view that externalizing behavior problems directly predict cannabis initiation. Such associations were inconsistent across informants and sexes and were often mediated by earlier smoking. Early smoking onset is a powerful predictor of later cannabis initiation independent of preceding externalizing behavior problems. Although externalizing behavior problems are important as a starting point for substance use trajectories, early-onset smoking should be identified as an important marker of cannabis use risk.

Objective: Cannabis is the most commonly consumed illicit drug among pregnant women. Intrauterine exposure to cannabis may result in risks for the developing fetus. The importance of intrauterine growth on subsequent psychological and behavioral child development has been demonstrated. This study examined the relation between maternal cannabis use and fetal growth until birth in a population-based sample., Method: Approximately 7,452 mothers enrolled during pregnancy and provided information on substance use and fetal growth. Fetal growth was determined using ultrasound measures in early, mid-, and late pregnancy. Additionally, birth weight was assessed., Results: Maternal cannabis use during pregnancy was associated with growth restriction in mid-and late pregnancy and with lower birth weight. This growth reduction was most pronounced for fetuses exposed to continued maternal cannabis use during pregnancy. Fetal weight in cannabis-exposed fetuses showed a growth reduction of -14.44 g/week (95% confidence interval -22.94 to -5.94, p = .001) and head circumference (-0.21 mm/week, 95% confidence interval -0.42 to 0.02, p = .07), compared with nonexposed fetuses. Maternal cannabis use during pregnancy resulted in more pronounced growth restriction than maternal tobacco use. Paternal cannabis use was not associated with fetal growth restriction., Conclusions: Maternal cannabis use, even for a short period, may be associated with several adverse fetal growth trajectories.

Aims: To ascertain demographic, emotional and social determinants of cannabis use in early pregnancy., Design: This study was embedded in the Generation R study, a multiethnic population-based cohort of parents and their children, followed from pregnancy to childhood., Setting: Rotterdam, The Netherlands., Participants: Mothers enrolled in pregnancy who answered questions about their own and their partners substance use before and during pregnancy (n=7610)., Measurements: Using self-report questionnaires, information was collected on maternal demographics, psychopathology, delinquency, childhood trauma, social stress, family functioning, and parental alcohol, tobacco and substance use. Multinomial logistic regression analysis was used, with non-using women as reference., Findings: 246 (3.2%) women used cannabis before pregnancy and 220 (2.9%) women used cannabis both before and during pregnancy. The strongest determinant for maternal cannabis use during pregnancy was cannabis use by the biological father of the child (OR=38.56; 95%CI=26.14-58.88). Maternal cannabis use during pregnancy was also independently associated with being single (OR=4.25; 95%CI=2.33-7.75) or having a partner without being married (OR=2.75; 95%CI=1.56-4.85), childhood trauma (OR=1.39; 95%CI=1.22-1.57) and delinquency (OR=3.37; 95%CI=1.90-5.98), but not with maternal age, ethnicity, psychopathology, family functioning and perceived stress. Being religious was protective (Islam: OR=0.25; 95%CI=0.09-0.65) for maternal cannabis use during pregnancy. Additionally, lower educational level determined continued cannabis use in ever-users (OR=3.22; 95%CI=1.54-6.74)., Conclusions: Our results showed that multiple demographic, emotional and social characteristics were associated with maternal cannabis use. These characteristics should be considered when investigating offspring exposed to cannabis in utero, as they may play an important role in mother-child interaction and child development.

Aims: To identify early onset cannabis users by measuring basal hypothalamic-pituitary-adrenal (HPA) axis activity, which may be a risk factor for early onset substance use when showing low activity., Design: In a prospective cohort study, adolescents who initiated cannabis use at an early age (9-12 years), those who initiated at a later age (13-14 years) and those who did not use cannabis by the age of 14 were compared with respect to HPA axis activity., Setting and Participants: Data were used from the first and second assessment wave of the TRacking Adolescents' Individual Lives Survey (TRAILS), that included 1768 Dutch young adolescents aged 10-12 years who were followed-up across a period of 2 years., Measurements: Cortisol was measured in saliva samples at awakening, 30 minutes later and at 8 p.m. at age 10-12. Self-reported age at first cannabis use was used., Findings: The early onset group had lower cortisol levels 30 minutes after awakening than the late onset group (OR = 0.93, 95% CI: 0.86-0.99). Furthermore, compared to non-users, the early and late onset cannabis users had higher levels of cortisol at 8 p.m. (OR = 1.25, 95% CI: 1.03-1.53 and OR = 1.21, 95% CI: 1.01-1.45, respectively)., Conclusions: Some evidence was found for HPA axis hypo-activity at awakening in adolescents with early onset of cannabis use compared to late onset users, which might indicate an increased risk for early onset users of seeking stimulation to restore arousal levels by using substances.

Abstract: Interest in fetal origins of adverse offspring outcomes has grown extensively in the last decade. This has resulted in many published studies focusing on exposure in utero to substances and human offspring outcomes. Exposure to maternal substance use in pregnancy is believed to be a preventable hazard, and is therefore a main issue for public health concern and policy. However, an important question in human studies remains whether prenatal substance use exposure has an aetiological role in pathways to adverse developmental and behavioural outcomes via teratological effects. Recent insights and developments in research methodology will aid the adequate and more refined testing of associations between prenatal substance use and offspring outcomes. In particular, novel approaches could assist in disentangling the exposure to substance effects from correlated risk factors. The purpose of this manuscript is therefore to provide an overview of methodological issues involved in studies that focus on the association between maternal substance use during pregnancy and offspring''s outcomes, to describe novel approaches to test these associations, and present some examples of new and well-designed studies and discuss their findings. [Copyright &y& Elsevier]

Abstract: Background: Although use of illicit drugs shows varying degree of heritability, the influence of shared and unique environmental factors predominate among adolescents. We explored factors predicting use of cannabis and other illicit drugs among Finnish adolescent twins. Methods: We used longitudinal data from the FinnTwin12–17 study with baseline at age 11–12 and follow-up at ages 14 and 17½, including 4138 individuals. The outcome was self-reported ever use of cannabis or other illicit drugs at age 17½. The potential predictors were measures reported by the twins, their parents or teachers. As individual factors we tested smoking, alcohol use, behavioral and emotional problems; as peer factors: number of smoking friends and acquaintances with drug experience; as family factors: parental substance use, socio-economic status and pre-natal exposure to nicotine. We used logistic regression models, controlling for twinship, age and sex, to compute odds ratios (OR) for each potential predictor. To adjust for within-family confounds, we conducted conditional logistic regressions among 246 twin pairs discordant for drug use. Results: 13.5% of subjects had initiated use of cannabis or other illicit drugs by age of 17½. When adjusted for within-family confounds, smoking, drinking, and aggressiveness, as well as smoking and drug use among peers predicted use of illicit drugs. In the final regression model, the significant predictors were female sex, early smoking onset, drinking to intoxication, having smoking peers and acquaintances with drug experience, father''s weekly drinking to intoxication, and aggressive behavior among boys. Smoking initiation by age of 12 was the most powerful predictor among individuals (OR=26, p <0.001) and within discordant pairs (OR=22, p <0.001). Conclusions: Early onset smoking is a powerful predictor for subsequent use of illicit drugs among Finnish adolescents, but the causal nature of this relationship needs to be clarified. [Copyright &y& Elsevier]

Objective: Increased knowledge about the mechanisms by which some individuals are at risk for early onset of cannabis use might contribute to the improvement of prevention efforts. We focus on the roles of early-adolescent high-intensity pleasure, disruptive behavior, and their interplay in the prediction of onset of cannabis use 2 years later. Method: Data from 81% (n = 1,804) of the participants (51.9% girls) of the Tracking Adolescents' Individual Lives Survey (TRAILS), a prospective general population study in the north of The Netherlands, were analyzed. Measures included parent-reported high-intensity pleasure, and parent and self-reported general disruptive behavior, attention-deficit hyperactivity, oppositional problems, and conduct problems (Child Behavior Checklist/6-18 and Youth Self-Report) at ages 10-12. Onset of cannabis use was assessed at age 12-14 by means of self-reports. Analyses were carried out in Mplus. Results: Early adolescent high-intensity pleasure and disruptive behavior, mainly conduct problems and to some extent attention-deficit hyperactivity, predicted the onset of cannabis use in adolescence. Although we found some mediation by general disruptive behavior, conduct problems, and attention-deficit hyperactivity, the contribution of high-intensity pleasure in predicting the onset of cannabis use was found to be mainly independent from disruptive behavior. Conclusions: The unique contribution of both high-intensity pleasure and disruptive behavior points in the direction of different pathways toward onset of cannabis use. [ABSTRACT FROM AUTHOR]

Abstract: Background: While temperamental characteristics have been related to the onset of cannabis use, it is not clear at what point(s) along the trajectory from early onset of tobacco use (EOT) to early onset of cannabis use (EOC) these characteristics exert their impact. This study examined if (1) temperamental characteristics predispose to EOT that on its turn predisposes to EOC, and (2) temperament moderates the importance of EOT on the progression to EOC. Methods: Data from 1848 (83%) participants in the TRacking Adolescents’ Individual Lives Survey (TRAILS), a prospective population study of Dutch adolescents, were analyzed. We used parent-reports on the Early Adolescent Temperament Questionnaire to assess the dimensions of high-intensity pleasure, frustration, effortful control, shyness and fearfulness at age 10–12. EOT and EOC were defined as use at least once before the ages of 12 and 13 years, respectively, assessed by means of self-reports. We performed mediation and moderation analyses in Mplus. Results: High levels of high-intensity pleasure predisposed to entrance in the trajectory from EOT to EOC. Once tobacco use had been initiated at early age, low levels of shyness and high levels of high-intensity pleasure increased the risk of progression to EOC. Conclusions: Besides a common liability for EOT and EOC based on temperament, the risk of transition from tobacco to cannabis use is modified by temperamental characteristics. Differences in interplay with other risk factors may explain the impact of temperament on distinct points along the substance use trajectory. [Copyright &y& Elsevier]