Collado, AnahiMajor depressive disorder (MDD) is highly prevalent among U.S. Spanish-speaking Latinos. Although MDD is very treatable, the lack of empirically-supported treatments precludes this population's access to quality mental health care. Following the promising results of a small open-label pilot study in which we tested the efficacy of Behavioral Activation Treatment for Depression (BATD) in a sample Latinos with Spanish-speaking preference, we conducted a randomized control trial (RCT; N = 46) that compared BATD (N = 23) to supportive counseling (N = 23) across various domains, including depression, BATD proposed mechanisms (activity level and environmental reward), and non-specific psychotherapy factors. Results indicated that relative to SC, BATD led to greater decreases in depressive symptoms over time (p = 0.04) and greater MDD remission at the end of treatment and at the one-month follow-up (p = 0.01). Activity level (p = 0.01) and environmental reward (p = 0.05) showed greater increases over time among participants who received BATD compared to SC. Further, proposed BATD mechanisms of change did not correspond over time with depressive symptomatology. Treatment adherence, therapeutic alliance, and treatment satisfaction did not differ between the groups (ps > 0.17). The one-month follow-up suggested sustained clinical gains across therapies. The current study adds to a limited treatment research literature and suggests that BATD, a time-limited and straightforward intervention, is efficacious in reducing depression and increasing activity level and environmental reward in this important, yet underserved population of the U.S. The current study sets the stage for a larger RCT to examine BATD against an empirically-supported treatment, with additional moderators of treatment and mechanisms of change.enEvaluating the Efficacy of Behavioral Activation Among Spanish-Speaking LatinosDissertationPsychologyBehavioral ActivationDepressionHealth disparitiesLatinosTreatment development