A burgeoning of research into child and adolescent substance use in the 1990s has significantly advanced our understanding of adolescent substance use disorders (SUDs) and of effective treatment approaches (Muck et al., 2001; Drug Strategies, 2003). Developmental research has demonstrated that adolescents who present for drug treatment have a broad range of behavioral problems, skills deficits, academic difficulties, and family and mental health problems, which have generally been shaped by a series of environmental adversities and biological vulnerabilities from early childhood (Dawes et al., 2000; Hops et al., 2000; Tarter, 2002; Tims et al., 2002). Developmental research has also supported the development of a number of manual-guided, behavioral, cognitive–behavioral, and family-based modalities that integrate treatment across multiple problem domains (Deas & Thomas, 2001; Muck et al., 2001; Riggs & Whitmore, 1999). A growing research and clinical consensus indicates that substance treatment is most effective when it attends to the multiple psychosocial problems and medical and mental health needs of adolescents in addition to their drug abuse. Such multimodal treatment, including the concurrent assessment and treatment of psychiatric comorbidity, is recommended by the leading research and clinical professional organizations in the field (AACAP, 1997; Drug Strategies, 2003; NIDA, 1999). Despite these recommendations, implementation of integrated treatment of comorbidity in substance treatment programs has lagged behind the integration of other treatment services owing to a number of barriers, including a lack of research evaluating the safety and efficacy of psychotropic medications in adolescents with SUD (Sohlkhah & Wilens, 1998).