How depressed are we? Prevalence of depression in Sri Lanka (2018-2019)

Abstract

Depression is a leading cause of disease burden and continues to be an ever-growing concern worldwide. While rates of depression are well studied in high-income countries, prevalence in low- and middle-income countries remains less understood. In Sri Lanka, the 2007 National Mental Health Survey (NMHS), which excluded the North and East due to ongoing civil conflict at the time, remains the most comprehensive source on Sri Lanka's depression prevalence, However, the MNHS is almost two decades old. More recent smaller cohort studies would suggest that rates of depression vary significantly across different sub-populations. Yet, due to inconsistencies in study design, assessment tools, and diagnostic criteria, whether these differences reflect true variation or are methodological artifacts is unclear. Furthermore, the recent national crises (e.g., the COVID-19 pandemic and the economic collapse) affected large segments of the population. However, due to the absence of robust baseline data, it has been difficult to assess the mental health impact of these events. This study reports pre-crisis baseline statistics on depression, which can inform future research. Using data from a nationally representative sample of 6,627 participants from the first wave of the Sri Lanka Health and Ageing Study (SLHAS), conducted between mid-November 2018 and mid-November 2019, we assess rates of depression using the PHQ-9 scale. Multiple imputation was employed to address missing data. Our findings show overall depression rates lower than those reported in the NMHS. Descriptive statistics and logistic regression were used to explore subgroup variation, revealing significant differences in depression prevalence by region, gender, age, ethnicity, marital status, socioeconomic status, and certain health indicators. Results indicate that vulnerable populations experience disproportionately higher rates of depression, underscoring the need for targeted policy interventions that take these vulnerabilities into consideration and prioritize mental health support for at-risk groups.