Comparative Effectiveness of Second-Generation Antidepressants in Reducing the Risk of Dementia in Elderly Nursing Home Residents with Depression

Abstract

Study objective: Second-generation antidepressants have been shown to improve cognition and depression symptomatology, which are the major risk factors for dementia; however, little is known about the comparative effectiveness of antidepressants in reducing the risk of dementia. Thus, the objective of this study was to evaluate the long-term comparative effectiveness of different antidepressant classes in reducing the risk of dementia in elderly nursing home residents with depression.

Design: Propensity score-adjusted retrospective cohort study.

Data source: Multistate Minimum Data Set-linked Medicare Parts A, B, and D data files.

Patients: A total of 25,108 nursing home residents (65 years and older) with a diagnosis of depression and without a dementia diagnosis who were Medicare beneficiaries and new users of selective serotonin reuptake inhibitors (SSRIs; 19,952 [79.5%]), serotonin-norepinephrine reuptake inhibitors (SNRIs; 2381 [9.5%]), or tetracyclic antidepressants (2775 [11.1%]) between 2007 and 2010.

Measurements and main results: New users of SSRIs, SNRIs, and tetracyclics were followed over a 2-year period for the occurrence of dementia. A Cox proportional hazards regression model was used to evaluate the comparative effectiveness of SNRIs and tetracyclics in reducing the risk of dementia, with the SSRI class used as the reference category after controlling for propensity scores and their interactions terms. The unadjusted incidence of dementia was 8.2% for SSRI users, 6.0% for SNRI users, and 7.2% for tetracyclic users. The propensity score-adjusted Cox model did not find any significant difference in the risk of dementia in elderly nursing home residents who used SNRIs (hazard ratio [HR] 0.99, 95% confidence interval [CI] 0.84-1.19) or tetracyclics (HR 1.01, 95% CI 0.87-1.17) compared with the SSRI users.

Conclusion: This study did not find any significant differences in reducing the risk of dementia among the new users of second-generation antidepressant classes. Further studies are needed to evaluate the profiles of second-generation antidepressants on cognition in this vulnerable population.

Keywords: dementia; depression; elderly; nursing home residents; second-generation antidepressants; selective serotonin reuptake inhibitor; serotonin-norepinephrine reuptake inhibitor; tetracyclics.