Validation of short screening tools for common mental disorders in Nigerian general practices

Abstract Objective The objective was to examine the psychometric properties of two brief screening questionnaires for common mental disorders in general practices in areas speaking the three main Nigerian languages. Method Consecutives attendees of selected general practices in Ibadan, Enugu and Kaduna were screened with the General Health Questionnaire 12-item version (GHQ12) and K6. We selected all cases and 50% of noncases for second-stage interview with the Composite International Diagnostic Interview. The receiver operating characteristic curves were generated for both questionnaires, and optimal cutoffs were determined. Exploratory factor analysis was done for both questionnaires. Results The K6 had an area under the curve (AUC) of 0.62 for depression and 0.58 for anxiety disorder. The GHQ12 had an AUC of 0.74 for depression, while that for generalized anxiety disorder was 0.6. The GHQ12 was able to correctly classify 75% of the subjects with or without depression, while the K6 was able to correctly classify 56% of the subjects with or without depression. The optimal cutoff for both questionnaires was 4, selecting the point of best balance of sensitivity and specificity. Conclusion The findings suggest that the GHQ12 will be a useful tool in screening for common mental disorders in general practice in Nigeria.