Multiple Problem Youth addresses the complex connections among drug abuse, delinquency, and mental health problems as they apply to adolescents and young adults. Interrelationships in this area exist in a vast variety of ways, further complicated by extraneous factors such as demographics, sex, and time. The authors incorporate these factors and analyze the correlations among substance use, delinquency, and mental health problems, as well as discussing developmental patterns and reviewing theories of deviant behavior.