## Abstract ## **Background:** Adolescent depression and anxiety symptoms are prevalent in Sub-Saharan African countries, yet treatment options are scarce, and stigma limits help-seeking. Brief, computerized single-session interventions (SSIs) that contain empirically supported stigma-reducing elements may help expand access to treatment. We developed and evaluated such an intervention for Kenyan adolescents. **Method:** High school students (N=103, age 13-18) were randomized to a digital SSI Shamiri-Digital (Shamiri means “thrive” in Kiswahili) or a study-skills control intervention. Shamiri-Digital consisted of reading and writing activities about three concepts: growth mindset, gratitude, and value affirmation. Both Shamiri-Digital and the study-skills control condition were delivered electronically in schools. **Results:** Compared to the control, Shamiri-Digital produced greater reduction in adolescent depression symptoms in both the full sample (p = 0.028, d = 0.50) and a sub-sample of youths with moderate-to-severe depression symptoms (p = 0.010, d = 0.83) from baseline to two-week follow-up. The effects exceed the mean effects reported in meta-analyses of full-length, face-to-face psychotherapy for youth depression. There were no significant effects on anxiety symptoms, well-being, or happiness. **Conclusion:** This is the first report that a brief, computerized SSI may reduce depressive symptoms in adolescents in Sub-Saharan Africa. Replication trials with extended follow-ups will help gauge the strength and durability of these effects. **Trial Registration Number:** PACTR201906810558181. Pan African Clinical Trials Registry (PACTR). ---------- ## Public Health Significance ## This study provides evidence that a brief single-session positive-psychology intervention may help reduce depressive symptoms of adolescents living in Sub Saharan Africa, where there are few mental health professionals, and stigma limits help-seeking