Investigating the Social Determinants of Treatment Gaps in Severe Mental Illness in Northern Nigeria Through a Multilevel Epidemiological Lens

Treatment gaps in severe mental illness across Northern Nigeria are profound, yet the multilevel social determinants driving these gaps have not been rigorously examined. This study applies a multilevel epidemiological framework to investigate individual, household, community, and health system determinants of treatment gaps in severe mental illness across Kano, Sokoto, Zamfara, and Adamawa States in Northern Nigeria. A multilevel cross-sectional design will recruit 1,200 adults with evidence of severe mental illness identified through community psychiatric case finding in 40 communities. The MINI will confirm diagnoses, and treatment receipt will be established through structured interview and health record linkage. Individual predictors will include gender, socioeconomic status, and illness insight. Household predictors will include family stigma and caregiver literacy. Community predictors will include distance to psychiatric facility, community attitudes (CAMI), and traditional healer density. Health system predictors will include facility-level mental health resource availability. Three-level hierarchical logistic regression models will partition variance across levels. This study generates original multilevel evidence to support targeted health system strengthening and community mental health investment in Northern Nigeria. Keywords: treatment gap, severe mental illness, multilevel epidemiology, Northern Nigeria, social determinants