2011

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.

Aims The aims of the present study were to determine the direct effect of DRD2 and DRD4, as well as their interaction with parenting (i.e. rejection, overprotection and emotional warmth), on the development of regular alcohol and cannabis use in 1192 Dutch adolescents from the general population. Methods Information was obtained by self-report questionnaires. Perceived rejection, overprotection and emotional warmth were assessed at age 10-12. Regular alcohol and cannabis use were determined at age 15-18 and defined as the consumption of alcohol on 10 or more occasions in the past four weeks, and the use of cannabis on 4 or more occasions in the past four weeks. Models were adjusted for age, sex, parental alcohol or cannabis use, and externalizing behavior. Results Carrying the A1 allele of the DRD2 TaqIA polymorphism, or the 7 repeat DRD4, was not directly related to regular alcohol or cannabis use. In addition, adolescent carriers of these genetic risk markers were not more susceptible to the influence of less optimal parenting. Main effects for parenting indicated that overprotection increased the risk of regular alcohol use, whereas the risk of cannabis use was enhanced by parental rejection and buffered by emotional warmth. Conclusions Our findings do not support an association between DRD2/DRD4 and regular alcohol and cannabis use in adolescents. Given the substance-specific influences of rejection, overprotection and emotional warmth, these parenting factors might be promising candidates for prevention work.

Aim. To examine the prospective relationship between externalizing and internalizing problems and cannabis use in early adolescence. Materials and Methods. Data were used from the TRAILS study, a longitudinal cohort study of (pre)adolescents (n = 1,449), with measurements at age11.1(T1), age13.6(T2)and age16.3(T3).Internalizing (with drawn behaviour, somatic complaints and depression) and externalizing (delinquent and aggressive behaviour) problems were assessed at all data waves, using the Youth Self Report. Participants reported on cannabis use at the second and third wave. Path analysis was used to identify the temporal order of internalizing and externalizing problems and cannabis use. Results. Path analysis showed no associations between cannabis use(T2-T3) and internalizing problems (T1-2-3). However, cannabis use and externalizing problems were associated (r ranged from.19–.58); path analysis showed that externalizing problems at T1 and T2 preceded cannabis use at T2 and T3, respectively. In contrast, cannabis use(T2) did not precede externalizing problems(T3). Conclusions. These results suggest that in early adolescence, there is no association between internalizing behaviour and cannabis use. There is an association between externalizing behaviour and cannabis use, and it appears that externalizing behaviour precedes cannabis use rather than the other way around during this age period.

Objective.This study examined (a) the predictive value of observed versus reported measures of impulsivity on the onset of cannabis use and determined if lifetime tobacco and cannabis users can be differentiated by their level of impulsivity and (b) the predictive value of observed versus reported measures of impulsivity on repeated cannabis use and determined if repeated tobacco and cannabis users can be differentiated by their level of impulsivity. Method. The present study involves 667 (50.5% female) adolescents assessed at two time points of the TRacking Adolescents' Individual Lives Survey (TRAILS). Adolescents in our study participated in the Bangor Gambling Task (BGT), as well as completed self-report questionnaires assessing cannabis use behavior (Mage = 16.11 years) and the Behavioral Inhibition System (BIS)/Behavioral Activation System (BAS) questionnaire (Mage = 13.56 years). Results. Higher levels of BAS functioning increased the likelihood that adolescents would ever use substances such as tobacco or cannabis during their lifetime. In contrast, low BIS functioning increased the likelihood of repeated cannabis use. Repeated tobacco users did not significantly differ from lifetime users by their BIS functioning. The BGT measures were not significant in relation to lifetime or repeated use of cannabis or tobacco. Conclusions. High BAS seems to be more important for experimental substance use, whereas low BIS seems to be more important for progression into regular cannabis use specifically. In contrast to the BIS/BAS, our laboratory test of impulsivity, the BGT, is not correlated with early-onset tobacco/cannabis use. Furthermore, the BGT is not correlated with the BIS/BAS measures.

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 assessmentwave. 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 stressreactivity 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.

Cannabis use has been associated with several problematic outcomes, such as educational problems, use of other (illicit) drugs, deviant peer affiliations and mental health problems. Because of these adverse outcomes, it seems crucial to identify risk factors of cannabis use. In the present study we investigated whether multiple social skills (cooperation, assertion and self control) are possible risk factors of cannabis use during adolescence.
Social skills were assessed by teachers, in a longitudinal cohort of (pre-) adolescents, with measurements at average ages 11.1 (baseline) and 16.3 years (follow-up). Prospective associations with participants’ self-reported use of cannabis, (age of) onset of cannabis use, and frequency of use at follow-up were examined using multinomial logistic regression analyses.
Social skills predicted different aspects of cannabis use independent of better-known factors such as presence of externalizing behavior and use of other substances. The direction of associations depended on the type of social skill. Good cooperation skills during early adolescence were associated with a reduced risk of lifetime cannabis use and a reduced risk of using cannabis on a regular basis. On the other hand, assertion at age 11 increased the risk of lifetime cannabis use and of using cannabis on an experimental basis.
Concluding, the present study showed that specific social skills are differentially related to cannabis use. Positive results regarding prevention of cannabis are obtained by stimulating or suppressing social behavior, depending on the type of social behavior and its context.

Objective. To study the prospective relationship between maternal smoking during pregnancy (MSP) and behavioral problems, heavy alcohol use, daily smoking, and ever use of cannabis in the offspring and to assess the role of confounding and mediating factors in a systematic way. Methods. Population based cohort study of 2,230 respondents, starting in 2001 when respondents were around the age of 11 years, and two follow-up measurements at intervals of about 2.5 years (response rates of 96.0% and 81.4%). Results. Almost one third of the respondents’ mothers had smoked tobacco during pregnancy. These respondents were at an increased the risk for all outcomes except internalizing behavioral problems (significant odds ratios ranged from 1.40 to 2.97). The successive models showed that the potential confounding factors reduced the strength of all relationships. In the full model, the strongest relationship was found for mothers who smoked more than 10 cigarettes a day during pregnancy and daily smoking in early adolescence (odds ratio: 1.56), but none of the relationships was statistically significant. Conclusions. MSP is a marker for future behavioral outcomes in the offspring, but reducing the prevalence of MSP is unlikely to make a meaningful contribution to the prevention of these problems in adolescents.