Implementation Outcomes Associated with Task-Shifting Mental Health Interventions in Sub-Saharan Africa: A Systematic Review

The treatment gap in sub-Saharan Africa (SSA) may limit access to mental health care delivered by trained non-specialist providers; however, implementation evidence has not been systematically mapped across the full Proctor framework.On September 2, 2026, we reran searches in PubMed, ScienceDirect, and Google Scholar for publications dated January 1, 2016 to December 31, 2025.Quantitative, qualitative, and mixed-methods primary studies conducted in SSA that evaluated a task-shifted mental health intervention and reported at least one implementation outcome or implementation determinant; a clinical mental health outcome was not required.Risk of bias was assessed with RoB 2 for randomized trials and ROBINS-I for non-randomized intervention studies.No protocol was prospectively registered.The available evidence set comprised fourteen studies from eight SSA countries.Appropriateness (n = 12), fidelity (n = 12), acceptability (n = 11), and feasibility (n = 10) were the outcomes most often measured, whereas adoption (n = 3), implementation cost (n = 2), penetration (n = 1), and sustainability (n = 1) were rarely assessed.Attendance, cultural adaptation, and service integration were not treated as sufficient evidence of acceptability, appropriateness, or sustainability unless the primary study explicitly linked them to those constructs.The evidence supports the feasibility of delivering selected interventions under supported research conditions, but does not establish successful routine implementation, cost-effectiveness, or long-term scale-up.Policy inference is limited by sparse data on adoption, cost, penetration, and sustainability; unavailable full texts; and the restriction to English-language peer-reviewed reports.