Psychiatric morbidity and substance use in young people aged 13–15 years: results from the Child and Adolescent Survey of Mental Health

Abstract
Background Psychoactive substance use is strongly associated with psychiatric morbidity in both adults and adolescents. Aims To determine which of alcohol, nicotine and cannabis is most closely linked to psychiatric disorders in early adolescence. Method Data from 2624 adolescents aged 13–15 years were drawn from a national mental health survey of children. The relationship between psychiatric morbidity and smoking, drinking and cannabis use was examined by logistic regression analyses. Results Having a psychiatric disorder was associated with an increased risk of substance use. Greater involvement with any one substance increased the risk of other substance use. Analyses of the interactions between smoking, drinking and cannabis use indicated that the relationship between substance use and psychiatric morbidity was primarily explained by regular smoking and (to a lesser extent) regular cannabis use. Conclusions In this sample, links between substance use and psychiatric disorders were primarily accounted for by smoking. The strong relationship is likely to be due to a combination of underlying individual constitutional factors and drug-specific effects resulting from consumption over the period of adolescent development and growth.