Current prevalence, comorbidity and associated factors for symptoms of depression and generalised anxiety in the Lagos State Mental Health Survey (LSMHS), Nigeria

Abstract Background Depression and anxiety are very prevalent, highly co-morbid, burdensome with huge treatment gaps in low and middle-income countries (LMICs). This study aimed to estimate the current prevalence of symptoms of depression and generalised anxiety, examine co-morbid conditions and associated sociodemographic factors in Lagos state, Nigeria. Methods A face to face household survey completed by 11,246 adult participants (age 18–75 years). Clinically significant symptoms of depression, generalised anxiety and somatic symptoms were assessed using the specific modules of the Patient Health Questionnaire (PHQ) respectively. Alcohol use, substance use and disability were assessed with the Alcohol Use Disorders Identification Test-short form (AUDIT-C), the Mini International Neuropsychiatric Interview (M.I.N.I) and the WHO Disability Assessment Schedule (WHODAS 2.0) respectively. Results The mean age was 36.75 (sd 12.3) years and there were 6525 (58.0%) females. The weighted current prevalence of symptoms of depression, generalised anxiety and combined depression/generalised anxiety were 5.5% (se 0.3), 3.5% (se 0.2) and 1.2% (se 0.1) respectively. About 20.9% of all cases of depressive symptoms have co-morbidity with symptoms of generalised anxiety. Symptoms of depression and generalised anxiety had high co-morbidity with somatic symptoms, alcohol use problems and disability but not substance use disorders. Being female, not married (especially separated/divorced or widowed) and unemployment were significantly associated with presence of either symptoms of depression or generalised anxiety. Conclusion Our findings suggest that despite the popularity of cross-national surveys, there is need for individual countries and states to generate complimentary local data to plan effective local response to close the huge treatment gap for common mental disorders.