Baseline mental health knowledge, diagnostic accuracy, treatment, and referral skills among primary healthcare workers in Kano, Northern Nigeria: a cross-sectional study

Mental health integration into primary health care (PHC) is widely advocated as the most feasible strategy to address the large treatment gap in low- and middle-income countries. However, baseline clinical decision-making skills of frontline primary healthcare workers (PHCWs) in the assessment, management, and referral of common mental, neurological, and substance use (MNS) disorders remain poorly documented, particularly in Northern Nigeria. This study assessed mental health knowledge, diagnostic accuracy, treatment, and referral skills among PHC workers in Kano, Nigeria. A cross-sectional study was conducted among 180 PHC workers selected through simple random sampling. Mental health knowledge was evaluated using the Mental Health Knowledge Questionnaire. Clinical decision-making skills were assessed with four culturally adapted clinical vignettes. Data were analysed using descriptive statistics, independent t-tests, ANOVA, and multivariable linear regression in IBM SPSS version 26, with statistical significance set at p < 0.05. The mean (SD) mental health knowledge score was 12.27 (2.62) out of 20 (61.35%), indicating moderate knowledge. The mean (SD) clinical decision-making score was 4.99 (2.72) out of 12. Diagnostic accuracy was highest for depression (77.7%) and lowest for substance use disorders (12.8%), while treatment and referral decisions were generally suboptimal. In multivariable analyses, higher educational attainment was independently associated with better mental health knowledge, whereas higher educational attainment and professional cadre became independently associated with better clinical decision-making. PHC workers in Kano demonstrated moderate mental health knowledge but limited clinical decision-making skills, particularly for substance use disorders. Higher educational attainment and professional cadre were associated with better performance. These findings support targeted mhGAP-based training and supportive supervision to strengthen mental health service integration in PHC in Kano State.