2009

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.

 Aims. We examined within a prospective longitudinal study whether cortisol levels were associated with smoking or drinking behaviors, taking parental substance use into account.
Design The influence of parental substance use on cortisol levels of their adolescent offspring at age 10-12 was examined. Next, cortisol levels of adolescents who initiated smoking or drinking at the first data collection (age 10-12) were compared to non-users. Finally, we examined whether cortisol levels could predict new onset and frequency of smoking and drinking two years later. Setting and participants. First and second assessment data of the TRacking Adolescents’ Individual Lives Survey (TRAILS) were used, including 1,768 Dutch adolescents aged 10-12 years, who were followed up across a period of two years. Measurements. Cortisol was measured in saliva samples at awakening, 30 minutes later, and at 8 p.m. at age 10-12. Self-reported substance use at age 10-12 and 13-14, and parental self-reported substance use were used. Findings. Only maternal substance use was related to slightly lower adolescent cortisol levels at 8 p.m. Both maternal and paternal substance use were associated with adolescent smoking and drinking at age 13-14, although fathers’ use only predicted the amount used and not the chance of ever use. Finally, higher cortisol levels were moderately related to current smoking and future frequency of smoking, but not to alcohol use. Conclusions. In a general population, parental heavy substance use does not seem to consistently affect cortisol levels in their offspring. We found some evidence for higher, instead of lower, HPA axis activity as a predictor of smoking in early adolescence.

 Background/Aims. Increased knowledge about the mechanisms by which some individuals are at-risk of 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 two years later. Methods. Data from 81% (N=1804) 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 (Early Adolescent Temperament Questionnaire; EATQ-R), and parent- and self-reported general disruptive behavior, attention-deficit hyperactivity (ADH), oppositional problems (OP) and conduct problems (CP) (Child Behavior Checklist/6-18 and Youth Self-Report) at age 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 CP and to some extent ADH, predicted the onset of cannabis use in adolescence. Although we found some mediation by general disruptive behavior, CP and ADH, 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 towards onset of cannabis use.