Sex Differences in Post-Stroke Depression in the Elderly

Objective: Post-stroke depression (PSD) occurs in approximately one-third of ischemic stroke patients. However, there is conflicting evidence on sex differences in PSD. We sought to assess sex differences in risk and time course of PSD in US ischemic stroke (IS) patients. We hypothesized that women are at greater risk of PSD than men, and that a greater proportion of women experience PSD in the acute post-stroke phase. Materials and Methods: We conducted a retrospective cohort study of 100% de-identified data for US Medicare beneficiaries admitted for ischemic stroke from July 1, 2016 to December 31, 2017. We calculated Kaplan-Meier unadjusted cumulative risk of depression, stratified by sex, up to 1.5 years following index admission. We performed Cox regression to report the hazard ratio (HR) for diagnosis of depression up to 1.5 years post-stroke in females vs. males, adjusting for patient demographics, comorbidities, length of stay, and acute stroke interventions. Results: In elderly stroke patients, females (n=90,474) were 20% more likely to develop PSD than males (n=84,427) in adjusted models. Cumulative risk of depression was consistently elevated for females throughout 1.5 years of follow-up (0.2055 [95% CI 0.2013–0.2097] vs. 0.1690 [95% CI 0.1639–0.1741] (log-rank p < 0.0001). HR for PSD in females vs. males remained significant in fully adjusted analysis at 1.20 (95% CI 1.17-1.23, p < 0.0001). Conclusions: Over 1.5 years of follow-up, female stroke patients had significantly greater hazard of developing PSD, highlighting the need for long-term depression screening in this population and further investigation of underlying reasons for sex differences.