Government-led scale-up of task-shifted mental health services in Lagos State, Nigeria: a mixed-methods...

Mental health conditions remain a leading contributor to global disability; however, treatment coverage in low- and middle-income countries (LMICs) stays below 20%; in Nigeria, services are underfunded and largely excluded from primary health care (PHC). This study documents the institutional processes through which the Transition-to-Scale phase of the Mental Health in Primary Care (MeHPriC) initiative scaled up task-shifted mental health services across Lagos State, Nigeria. A retrospective, mixed-methods descriptive-explanatory case study was conducted across 57 PHCs and five general hospitals. The intervention delivered care for five priority mental, neurological, and substance use conditions using the Mental Health Gap Action Programme (mhGAP) framework; 890 health workers were trained, comprising 400 Community Health Extension Workers (CHEWs), 250 nurses, 150 medical officers, 85 lay counsellors, and 5 district psychiatrists, under structured district-level supervision. Data from service registers, supervision checklists, stock audits, provider and client surveys, key informant interviews, focus groups, and policy documents were analysed using descriptive statistics and hybrid deductive-inductive thematic coding organized around the World Health Organization (WHO) Health System Building Blocks and selected Consolidated Framework for Implementation Research (CFIR) constructs. The initiative was associated with institutional changes across governance (establishment of a Mental Health Desk and a multisectoral Stakeholders Council), workforce supervision (fidelity rising from 13% to 92.3% of facilities conducting weekly case reviews), medicines (six psychotropic medications added to the Essential Medicines List; stockouts reduced by 42%), financing (₦75 million allocated through routine government budgeting), service delivery (64 107 clients screened and 9138 initiated on treatment), and health information systems. Interpreted as incremental strengthening within the mental health subsystem, these findings reinforce the feasibility of mhGAP-aligned task-shifted care when supported by structured supervision and governance, while persistent fiscal and operational constraints underscore the fragility of institutional gains.