Prevalence of Depression and Associated Factors in Adults aged 18-69 years in Tanzania: Results from the 2023 National STEPS Survey

Background: Depression is an important contributor to morbidity and is increasingly recognized as a public health concern in low- and middle-income countries. Nationally representative estimates and associated factors are needed to inform integration of preventive and treatment services for mental health into primary care in Tanzania. Methods: We analyzed data from the 2023 Tanzania National STEPS Survey, a cross-sectional, household-based survey conducted in all regions of mainland Tanzania and Zanzibar among adults aged 18–69 years. Depressive episodes in the past 12 months was assessed using the WHO STEPS mental health module, which is based on the PHQ9 tool. Weighted descriptive analyses of estimated national prevalence. Associations between depression and sociodemographic and health-related factors were examined using modified Poisson regression to estimate incidence rate ratios (IRRs). Results: Overall, 20.3% of adults reported a depressive episode in the past 12 months. Prevalence was higher among women than men (27.6% vs 18.4%) and increased with age, reaching 29.9% among adults aged 46–69 years. In multivariable models, male sex was associated with lower prevalence of depression (adjusted IRR 0.78). Being separated/divorced/widowed was associated with higher prevalence compared with being married/cohabiting (adjusted IRR 1.42). Depression prevalence varied substantially by geographic zone, and participants with high cardiovascular risk had higher prevalence than those without high cardiovascular risk. Conclusions: One in five Tanzanian adults aged 18–69 years reported depressive episode in the past year, with higher prevalence among women, older adults, and those without partners, and with marked geographic variation. These findings support strengthening and targeting depression screening and psychosocial support within primary health care and within services for chronic conditions.