Mental Health Policy Interventions in Nigeria: A Scoping Review of Development, Implementation, and Outcomes

Mental health policy reforms in Nigeria exemplify a broader low-and middle-income country challenge: translating progressive legislation into equitable, scalable service delivery within resource-constrained, decentralised systems.This scoping review maps policy evolution from the custodial Lunacy Ordinance (1916) to the rights-based Mental Health Act (2023), analysing implementation using the Walt and Gilson Policy Triangle framework (context, content, processes, actors).Findings reveal persistent policy-practice gaps.Although Nigeria has enacted comprehensive mental health legislation, implementation remains constrained by chronic underinvestment (3.3% of health budget), severe specialist shortages (0.15 psychiatrists per 100,000 population), and fragmented federal-state-local governance.Legislative adoption lacks commensurate budgetary