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.

We investigated the temperamental traits high-intensity pleasure (temperamental activation) and shyness (temperamental inhibition) in relation to autonomic function as measured by heart rate (HR), respiratory sinus arrhythmia (RSA), and baroreflex sensitivity (BRS) in 938 10–13-year-old preadolescents from a population cohort. Temperament was evaluated by parent reports on the Revised Early Adolescent Temperament Questionnaire. Autonomic measurements were obtained in supine and standing position. High-intensity pleasure was negatively associated with supine HR and positively with supine RSA and BRS in both genders. Shyness was positively related to supine BRS in girls only. Orthostatic-based autonomic reactivity (difference) scores adjusted for supine values were unrelated to temperamental measures. It appeared that higher scores on temperamental activation and inhibition are associated with higher cardiac vagal activity (RSA) and/or flexible regulation of autonomic balance (BRS), implicating healthy physiological functioning. Moreover, results suggest a physiological basis promoting the tendency towards engagement in high-intensity activities.

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.