Understanding comorbidity between substance use, anxiety and affective disorders: broadening the research base.

In this paper, we argue that the research base for understanding comorbidity between substance use and other mental disorders needs to be broadened. We specifically advocate for: 1) more prospective epidemiological studies of relationships between alcohol and other drug use disorders and anxiety and mood disorders; 2) greater use of twin study designs to disentangle shared genetic and environmental contributions to comorbidity; 3) prospective neuroimaging studies of the effects of early and sustained alcohol and drug use on the developing adolescent brain; 4) a greater focus on the effects on comorbidity of primary and secondary prevention interventions for substance use, anxiety, affective and conduct disorders among children and adolescents; and 5) better evaluations of the impact of treatment upon persons with comorbid substance use and other mental disorders.