Developmental trajectories into substance use in adolescence

Abstract

The present study examined cross-sectional and longitudinal developmental characteristics of the association between mental health and substance use. N=1182 adolescents aged between 11 and 20 years were recruited from schools in Australia. Participants completed the Youth Self Report (YSR) (Achenbach, 1991a) and reported on their use of alcohol, tobacco, and marijuana, their social ability, their motivation for using substances, their ability to regulate emotion, and the influences of their parents and peers on their substance use. N=561 of time one participants were retained for testing one year later to assess the potential to predict substance use at time two from mental health at time one. Results indicated a clear and consistent cross-sectional association between externalising scores on the YSR and use of the three substances, regardless of gender. The relation between internalising scores and substance use was non-significant. When the relation between externalising scores and substance use was assessed for mediation, only the influence of parents and peers was found to be significant. A cross-sectional structural model developed to account for this association was demonstrated to be invariant across the three substances of interest, and across gender, but not age category. There was no evidence that social skills, emotion regulation, or substance use motives, had roles in mediating the relationship between mental health and substance use. A model was developed to assess the potential to predict substance use at time two from externalising scores at time one. Results showed that externalising scores predicted increases in alcohol use via parent and peer attitudes. Thus, externalising disposition, in the context of a facilitative social environment, was predictive of an increase in alcohol use over time. Structural models developed to account for the predictive relation between externalising scores and use of cigarettes and marijuana

proved unstable and could not be tested. Substance use at time one was not predictive of externalising scores at time two. The results of the present research are discussed in relation to their potential to inform the developmental substance use literature, and efforts directed against the development of substance use problems. Limitations of the present research are noted.