Externalizing Behavior Problems and Cigarette Smoking as Predictors of Cannabis Use: The TRAILS Study

Accepted 23 September 2009.

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.

Key Words: externalizing problems, cigarette smoking, cannabis, adolescents

a National Institute of Health and Welfare & University of Helsinki, Helsinki, Finland

b Erasmus Medical Center, Rotterdam, The Netherlands

c University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

d Interdisciplinary Center for Psychiatric Epidemiology (ICPE), University Medical Center Groningen and University of Groningen, The Netherlands, and the Graduate School for Experimental Psychopathology, The Netherlands

e University of Amsterdam, The Netherlands

Correspondence to Dr. Tellervo Korhonen, University of Helsinki, Department of Public Health, P.O.Box 41, FIN - 00014 Helsinki

This research is part of the TRacking Adolescents' Individual Lives Survey (TRAILS). Participating centers of TRAILS include various departments of the University Medical Center and University of Groningen, the Erasmus University Medical Center Rotterdam, the University of Utrecht, the Radboud Medical Center Nijmegen, and the Trimbos Institute, all in the Netherlands. Principal investigators are Prof.dr. J. Ormel (University Medical Center Groningen) and Prof.dr. F.C. Verhulst (Erasmus University Medical Center). TRAILS has been financially supported by various grants from the Netherlands Organization for Scientific Research NWO (Medical Research Council program grant GB-MW 940-38-011; ZonMW Brainpower grant 100-001-004; ZonMw Risk Behavior and Dependence grants 60-60600-98-018 and 60-60600-97-118; ZonMw Culture and Health grant 261-98-710; Social Sciences Council medium-sized investment grants GB-MaGW 480-01-006 and GB-MaGW 480-07-001; Social Sciences Council project grants GB-MaGW 457-03-018, GB-MaGW 452-04-314, and GB-MaGW 452-06-004; NWO large-sized investment grant 175.010.2003.005); the Sophia Foundation for Medical Research (projects 301 and 393), the Dutch Ministry of Justice (WODC), and the participating universities. We are grateful to all adolescents, their parents, and teachers who participated in this research and to everyone who worked on this project and made it possible. The present analysis was also supported in part by the Netherlands Organization for Scientific Research (NWO) – Vidi scheme, Netherlands (452-06-004 to ACH, TK, and APvL).

Disclosure: Dr. Verhulst is author and head of the department of child and adolescent psychiatry at Erasmus MC, which publishes the Achenbach System of Empirically Based Assessment (ASEBA) and from which he receives remuneration. Drs. Korhonen, Reijneveld, Ormel, and Huizink, and Ms. van Leeuwen report no biomedical financial interests or potential conflict of interest.

PII: S0890-8567(09)00003-3

doi:10.1016/j.jaac.2009.09.001

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