Substance misuse and psychiatric comorbidity in adolescents.

PURPOSE OF REVIEW: Many young people are misusing and becoming dependent on multiple substances (especially nicotine, alcohol, and cannabis), with a complex variety of psychological effects. RECENT FINDINGS: Analysis of interactions between smoking, drinking, and cannabis use indicates that the relationship between substance use and psychiatric comorbidity is primarily explained by regular smoking. In some studies the use of cannabis on a regular basis was associated with an increased risk of psychiatric illness. This is by no means the case for all studies, so this area of work remains controversial. Children with attention deficit hyperactivity disorder who are substance misusers have a poorer prognosis than those without it so there is concern about treatment with stimulant drugs: this fear appears not to be substantiated by one study. Young people with anxiety disorders are at increased risk of substance use disorders. Clinical trials for adolescent substance abuse treatment have provided support for the benefits of cognitive behavioural interventions. There is an accumulating evidence base for pharmacological treatment for adult substance misusers that can inform treatment for younger patients. It is estimated that, of those adolescents who were likely to be in need of help, only about 9% received treatment. SUMMARY: Since psychiatric disorders beginning in childhood may continue into adult life, there is an opportunity to intervene to prevent or reduce conditions complicated by substance misuse, if services are accessible. The need for longitudinal work is vital to explore the patterns of comorbidity, and implement and evaluate appropriate treatment interventions.