Depression among stroke survivors: a community-based, prospective study from Kolkata, India

Post-stroke depression (PSD) is a disabling entity among stroke survivors (SS). Longitudinal studies on PSD, essential to determine its prognosis, are lacking from developing countries. This prospective study was undertaken to assess the prevalence, natural history, and correlates of depression among SS in an Indian community.

From a community based stroke registry, SS were assessed annually for cognition, disability, and depression using Bengali validated scales. PSD was diagnosed if score on geriatric depression scale was greater than or equal to 21. Complex sample strategy was considered when calculating prevalence of post stroke depression. An age- and sex-matched case-control study was undertaken to determine the odds of depression in SS.

Prevalence of PSD was 36.98% (95% confidence interval [CI]: 31.89%-42.06%) among 241 patients assessed at baseline. About 17% developed depression annually and a similar proportion had spontaneous improvement. Peak rate of PSD was beyond 3 months and continued up to 18 months after stroke. Compared to the non-depressed group, PSD subjects were significantly older, had higher age at first stroke, less education, lower socioeconomic status, and greater cognitive impairment and disability. Education had a protective role. Mortality in PSD was nearly twice that in non-depressed patients, though not significant statistically (hazard ratio: 1.84; 95% CI: 0.90-3.77). Compared with controls, odds ratio of PSD was 19.95 (95% CI: 10.09-39.47).

Approximately one-third of SS develop PSD, similar to developed countries. Prevalence remains stable annually. Delayed peak of PSD suggested later realization of underlying disability. Predictors of PSD have been described and higher literacy was protective in this study.