Psychiatric and psychosocial predictors of substance use disorders among adolescents: longitudinal study.

Background: Few studies have prospectively examined psychosocial and psychiatric predictors of adolescent substance use disorders simultaneously.

Aims: To identify psychosocial and psychiatric predictors of substance use disorders in adolescence.

Method: School children aged 12 years (s.d.=0.3) free from any substance use disorder at grade 7 (n=428) were assessed in three consecutive years, using a standardised psychiatric interview. Their baseline psychosocial information was also collected. The outcome was the onset age of a substance use disorder. The Cox regression model was used for data analysis.

Results: The most significant predictive factors for adolescent substance use disorder included male gender, attention-deficit hyperactivity disorder, conduct disorder and sibling use of tobacco. Three protective factors against such morbidity included living in a household with two parents, a good academic grade at grade 7 and objection to the use of substances.

Conclusions: Early intervention for disruptive behaviour disorders and specific psychosocial risk factors might prevent substance use disorders in early adolescence.