Prevalence and Sociodemographic Correlates of Depression and Thoughts of Self-Harm Among Adolescents in Five Low- and Middle-Income Countries: Evidence from the Demographic and Health Survey Program

Background Adolescence is a critical period for the onset of depression and self-harm, yet comparable, nationally representative estimates from low- and middle-income countries (LMICs) remain scarce. Existing evidence relies heavily on school-based samples, excluding out-of-school adolescents. The recently available data from Demographic and Health Surveys (DHS) Mental Health Module offers an opportunity to address this gap. Methods and findings We analysed data from 16,269 adolescents aged 15–19 years across five DHS surveys: Bangladesh (2022), Lesotho (2023–24), Mozambique (2022–23), Nepal (2022), and Zambia (2024). Probable depression was defined as a PHQ-9 score ≥10, and thoughts of death or self-harm as any endorsement of PHQ-9 item 9. We estimated survey-weighted prevalence by country, sex, and age, examined symptom profiles, and used sex- and country-specific modified Poisson regression to identify sociodemographic correlates. The country-normalised pooled prevalence was 3.9% (95% CI 3.4–4.5) for probable depression, ranging from 0.6% in Zambia to 6.5% in Mozambique, and 7.0% (95% CI 6.4–7.7) for thoughts of death or self-harm, ranging from 3.1% to 10.2%, respectively. Girls had higher prevalence than boys for both depression (4.9% vs 1.9%) and thoughts of death or self-harm (8.6% vs 3.9%), although sex differences varied across countries. No consistent age gradient emerged. Associations with household composition, marital and parental status, urban residence, education, and wealth were heterogeneous across settings. Interpretation is limited by the lack of population-specific PHQ-9 validation and cross-country measurement invariance testing, the inability of item 9 to distinguish passive death wishes from suicidal ideation, the restriction to ever-married girls in Bangladesh, and the cross-sectional design. Conclusions Across five LMICs, PHQ-9-defined probable depression was relatively uncommon, while thoughts of death or self-harm affected approximately one in fourteen adolescents, particularly in girls. Substantial cross-country variation highlights the need for context-sensitive adolescent mental health surveillance and prevention, including out-of-school populations, supported by repeated household surveys and locally validated measures.