A literature review on community studies of adolescent substance use, abuse, or dependence (SU/AID) and psychiatric comorbidity yielded 22 articles from 15 studies with information on rates, specificity, timing, and differential patterns of comorbidity by gender, race/ethnicity, and other factors. Results revealed that 60% of youths with SU/A/D had a comorbid diagnosis, and conduct disorder (CD) and oppositional defiant disorder (not attention-deficit/hyperactivity disorder) were most commonly associated with SU/A/D, followed by depression. Child psychopathology (particularly CD) was associated with early onset of substance use and abuse in later adolescence. The authors suggest that available data relevant to SU/A/D and psychiatric comorbidity can be used to better address such questions.