Association between depressive symptoms and tuberculosis diagnosis stage in older adults: a 4-year longitudinal cohort study in rural South Africa.

Abstract

While tuberculosis (TB) is associated with increased depressive symptoms, the long-term mental health trajectory post-diagnosis in low-resource settings remains poorly understood. This study investigated the longitudinal progression of depressive symptoms among individuals diagnosed with TB and evaluated whether symptom severity persisted or attenuated over time. Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa. Population-based cohort study. Rural Agincourt subdistrict, Mpumalanga province, South Africa, a high-TB-burden, resource-constrained region. Adults aged 40 years and older who were permanent residents of the Agincourt subdistrict (N=5059 at baseline). Depressive symptoms were assessed using the Centre for Epidemiologic Studies Depression Scale (CES-D) 8 (Wave 1) and CES-D 20 (Wave 2), with standardised scores enabling cross-wave comparisons. TB diagnosis status (self-reported) was categorised as recently diagnosed, previously diagnosed or never diagnosed. At baseline, HIV prevalence was significantly higher (p<0.001) among those recently diagnosed (37.0%) and previously diagnosed (26.9%) compared with those never diagnosed (10.2%). Individuals recently diagnosed with TB had significantly higher standardised CES-D scores (unadjusted β=0.32, 95% CI 0.15 to 0.50, p<0.001) compared with those never diagnosed, a finding that remained robust after adjusting for socio-demographic and health covariates (β=0.31, 95% CI 0.14 to 0.49, p<0.001). The odds of moderate depressive symptoms (OR=1.70, 95% CI 1.22 to 2.36, p<0.001) and severe depressive symptoms (OR=1.77, 95% CI 1.23 to 2.55, p<0.001) were significantly elevated. By Wave 2 (4-year follow-up), individuals with a recent TB diagnosis remained at a significantly higher risk of severe depression (OR=1.52, 95% CI 1.05 to 2.22, p<0.05). A recent TB diagnosis is strongly associated with depressive symptoms at baseline, and with the persistence of severe depressive symptoms 4 years later. These results were robust to a number of sensitivity tests and do not seem to be driven by differences in healthcare utilisation. Integrating mental health support into TB care programmes at all phases of diagnosis and treatment, particularly in low-resource settings, may have significant benefits.