Exploring the Mechanisms and Cost-Effectiveness of Mobile Phone-Based Tele-Support Psychotherapy Delivered by Lay Counselors for Depression Among Youth in Uganda: Secondary Analyses of a Pilot Randomized Controlled Trial

Background: Depression is a critical public health issue among youth in Uganda, with limited access to mental health services. We conducted secondary analyses of a pilot randomized controlled trial (RCT) to explore the mechanisms and cost-effectiveness of mobile phone-based Tele-Support Psychotherapy (TSP) delivered by lay counselors for youth with depression in Kampala. Methods: We conducted secondary analyses of a pilot RCT in which 300 youth aged 15–30 with mild to moderate depression were randomized (1:1) to engage with a mobile phone-based TSP service combined with Standard Mental Health Services (SMHS) or SMHS alone. Assessments at baseline, 6, and 12 months measured depression using the Self-Reporting Questionnaire-20 (SRQ-20), stigma, and income generation. Generalized structural equation modeling (GSEM) explored mediation pathways, and a provider-perspective cost-effectiveness analysis calculated the incremental cost-effectiveness ratio (ICER) using disability-adjusted life years (DALYs). Results: TSP significantly reduced depressive symptoms in 6 and 12 months after initiation of the sevice. Single-mediator analyses identified improvements in perceived social support: β= -0.218; 95% CI (-0.405, -0.031) and self-esteem: β= -0.325; 95% CI (-0.527, -0.124) as significant independent mediators of the intervention effect during the first six months. Exploratory sequential mediation analyses identified the perceived social support–self-esteem pathway as the only pathway with a significant overall indirect effect: β= -0.433; 95% (-0.855, -0.012); however, the sequential indirect effect was not statistically significant. The incremental cost-effectiveness ratio (ICER) was US$2,293 per disability-adjusted life year (DALY) averted, demonstrating that tele-support psychotherapy was cost-effective relative to Uganda's GDP per capita threshold (US$1,002). Conclusions: Mobile phone-based TSP is a promising and potentially cost-effective intervention for youth depression in low-resource settings. The identified mechanisms can inform intervention refinement before evaluation in a fully powered definitive randomized controlled trial.