Association between selective serotonin reuptake inhibitors and mortality following COVID-19 among patients with Alzheimer's disease.

Background: Recent research suggests that selective serotonin reuptake inhibitors (SSRIs) may reduce mortality in COVID-19 patients; however, research into their benefits for elderly Alzheimer's disease (AD) patients remains limited.

Objective: To investigate the relationship between SSRIs therapy and the mortality risk after COVID-19 infection in elderly patients with and without AD.

Methods: This retrospective cohort study leveraged a large database containing over 100 million electronic health records in the US from the TriNetX platform to compare the hazard rates of mortality after COVID-19 infection in elderly AD patients prescribed SSRIs versus propensity-score matched individuals prescribed other antidepressants. This study was also conducted in separate cohorts of patients without AD to compare the findings.

Results: When compared with non-SSRI antidepressants, SSRIs were associated with lower risk for mortality after COVID-19 infection in elderly patients without AD over early, middle, and later stages of the pandemic with HRs of 0.84 (95% CI: 0.75-0.93), 0.86 (95% CI: 0.79-0.93), and 0.77 (95% CI: 0.71-0.33), respectively. When comparing SSRIs with non-SSRI antidepressants for mortality risk following COVID-19 among patients with AD, HRs of 0.95 (95% CI: 0.71-1.27), 0.80 (95% CI: 0.61-1.06), and 0.99 (95% CI: 0.75-1.32), were found respectively.

Conclusions: Our findings suggest that the use of SSRIs is significantly associated with reduced mortality risk following COVID-19 in elderly patients without AD compared to other antidepressants. While a lower mortality risk was also observed among AD patients, the association was not statistically significant.