The present study describes the adaptation and open trial of The Unified Protocol for Transdiagnostic Treatment of Emotional Disorders in Adolescents (UP-A; Ehrenreich-May et al., 2018) adapted as a group-based intervention in a Chicago Public High School among predominantly low-income Black and Latine adolescents experiencing elevated depression symptoms (i.e., "Healthy Minds, Happy Lives program," HMHL). This study utilized qualitative and quantitative analyses to evaluate: (1) the systematic adaptation process that aimed to balance fidelity (to the original UP-A intervention) and flexibility (e.g., the school-based group delivery, and community partner engagement) (2) the initial feasibility and acceptability of the HMHL intervention by analyzing salient themes from focus groups and (3) pre- to post-intervention changes in symptoms, in order to inform intervention refinement and methodological considerations for a pilot clinical trial. Our adaptation process utilized the Framework for Reporting Adaptations and Modifications to Evidence-based Interventions and relied on the engagement of key school-staff partners (N=8) and student-trial participants with elevated depression symptoms (N=16). Focus group content was coded and thematically analyzed. Outcome trends were evaluated using reliable change indices. Preliminary findings were promising, such that participants attended an average of seven out of eight HMHL sessions. Retention was excellent with 100% of participants completing the program. Additionally, a majority of trial participants demonstrated a clinically meaningful reduction in depression symptoms and increased emotional state awareness following the intervention. Overall, HMHL may be a feasible and acceptable intervention for increasing access to care for youth who may otherwise not have the opportunity for evidence-based services. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]