Magidson, Jessica FDespite the prevalence of depression among substance users and the negative impact of depressive symptoms on substance abuse treatment outcomes, few interventions targeting depression have been developed to meet the needs of depressed substance users, particularly in low-income urban areas. The current study aimed to replicate and expand upon promising preliminary findings for the use of a brief behavioral activation approach [Life Enhancement Treatment for Substance Use (LET'S ACT; Daughters et al., 2008)] to treat depression in the context of inner-city residential substance abuse treatment. Main extensions to the previous study include a comparison of LET'S ACT to a contact-time matched control treatment, Supportive Counseling (SC), and a more definitive evaluation of the effect of LET'S ACT on substance abuse treatment dropout. Results indicated that compared to SC, participants receiving LET'S ACT evidenced significantly lower rates of substance abuse treatment dropout and depressive symptoms, as evidenced by a significant treatment x time interaction with the change in self-reported and clinician-rated depressive symptoms from baseline to the 2-week follow up, as well as significantly higher rates of behavioral activation, as evidenced by a significant treatment x time interaction with scores on the Behavioral Activation for Depression Scale (BADS) from pre- to post-treatment. This study builds on preliminary evidence for LET'S ACT as a short-term behavioral treatment for depression in residential substance abuse treatment and offers initial support for the effect of LET'S ACT on substance use outcomes.ThesisPsychology, ClinicalPsychology, BehavioralHealth Sciences, Public Healthbehavioral activationdepressionsubstance usetreatment dropout