Comparing antidepressant treatment patterns in older and younger adults: a claims database analysis.

Objectives: To compare depressed older (≥65) and younger (25-64) adults with regard to antidepressant treatment patterns and to assess factors associated with 180-day nonpersistence.

Design: Retrospective matched cohort study.

Setting: U.S. managed care population.

Participants: Older and matched younger adults diagnosed with depression and treated with antidepressants.

Measurements: Sociodemographic characteristics, comorbidities, polypharmacy, and characteristics of antidepressant treatment at 180 days were compared between older and younger adults. Analyses were conducted before and after the implementation of Medicare Part D on January 1, 2006, to consider the effect of this policy.

Results: Few participants received psychotherapy, especially older ones; rates were constant before and after 2006. Before 2006, older adults more frequently received antidepressants at lower (odds ratio (OR)=5.38, 95% confidence interval (CI)=3.57-8.13) or intermediate dose (OR=2.42, 95% CI=1.93-3.02) and had poorer adherence to treatment (P<.001) than younger adults. After 2006, older adults received similar proportions of intermediate or high antidepressant doses as younger adults, but a lower dosage was still more likely to be prescribed (OR=1.87, 95% CI=1.09-3.20) and had higher treatment adherence (P<.001). Medication profile did not significantly affect the risk of nonpersistence, but increased with lower antidepressant dose (P<.001). Whereas nonpersistence was higher in older adults before 2006 (hazard ratio (HR)=1.25, 95% CI=1.22-1.46), the trend reversed after 2006 (HR=0.76, 95% CI=0.66-0.88).

Conclusion: More than half of participants with depression discontinued antidepressant treatment, and psychotherapy was rarely used. Implementation of Medicare Part D was associated with substantial changes in treatment of older adults with depression. The presence of comorbidities or polypharmacy was not associated with nonpersistence in depressed older adults.