Mental health policy interventions in Nigeria: A scoping review of development, implementation and outcomes

Approximately 20% of Nigerians experience a mental health condition, yet fewer than 10% receive minimally adequate care. This scoping review synthesises the development, implementation and outcomes of mental health policies in Nigeria from 1916 to 2025. Using Arksey and O'Malley's framework, systematic searches were conducted across PubMed, Web of Science, PsycINFO, AJOL and Google Scholar (inception-December 2024), supplemented by grey literature from governmental and non-governmental sources. The Walt and Gilson Policy Triangle guided the analysis of policy context, content, processes and actors. Nigeria's policy trajectory demonstrates normative progress, transitioning from custodial approaches under the Lunacy Ordinance (1916) to a rights-based orientation in the Mental Health Act (2023). However, implementation outcomes remain constrained. Workforce expansion has been modest (psychiatrists increased from 250 in 2018 to approximately 350 in 2024), treatment coverage remains low (10-15%) and budget allocation is insufficient (3.3% of the health budget). Barriers include inadequate financing, weak coordination across federal and state levels, limited stakeholder engagement and insufficient integration of community, traditional and faith-based providers. Comparative analysis highlights that Ghana's autonomous Mental Health Authority, South Africa's provincial directorates and Kenya's community health volunteer model provide governance and implementation structures absent in Nigeria. Findings indicate that Nigerian mental health policies, while necessary, are insufficient alone for system strengthening. Effective policy translation requires increased and protected financing (target: 5% of health budget by 2027), task-shifting strategies, establishment of a National Mental Health Information System, federal incentives for state-level adoption, integration into primary healthcare (5,000 PHCs by 2028) and inclusive governance that incorporates service users and traditional healers.