Aspirin and incident depressive symptoms: A longitudinal cohort study over 8 years

Objective: Aspirin exhibits anti-atherosclerotic and anti-inflammatory properties--two potential risk factors for depression. The relationship between aspirin use and depression, however, remains unclear. We investigated whether the aspirin use is associated with a decreased incidence of depressive symptoms in a large North American cohort. Methods: Data from the Osteoarthritis Initiative dataset, a multicenter, longitudinal study on community-dwelling adults was analyzed. Aspirin use was defined through self-report in the past 30 days and confirmed by a trained interviewer. Incident depressive symptoms were defined as a score of >=16 in the 20-item Center for Epidemiologic Studies-Depression scale. Results: A total of 137 participants (mean age 65 y, 55.5% female) were using aspirin at baseline. Compared with 4003 participants not taking aspirin, no differences in Center for Epidemiologic Studies-Depression at baseline were evident (P =.65). After a median follow-up time of 8 years, the incidence of depressive symptoms was similar in those taking aspirin at baseline (43; 95% CI, 3-60) and in aspirin nonusers (38; 95% CI, 36-41) per 1000 y; log-rank test = 0.63). Based on Cox's regression analysis adjusted for 11 potential confounders, aspirin use was not significantly associated with the development of depressive symptoms (hazard ratio = 1.12; 95% CI, 0.78-1.62; P =.54). Adjustment for propensity scores or the use of propensity score matching did not alter the results. Conclusion: Our study found that prescription of aspirin offered no significant protection against incident depressive symptoms. Whether aspirin is beneficial in a subgroup of depression with high levels of inflammation remains to be investigated in future studies.