National trends in the use of antidepressants between 1997 and 2009 and the role of medicare part d implementation

Objectives: This study examined national trends in antidepressant use before and after implementation of Medicare Part D and compared utilization among individuals with different types of insurance. Methods: The data source was the Medical Expenditure Panel Survey Household Component (1997- 2009), and logistic regression was used for the analysis. Results: The odds of antidepressant use among people with depression increased between 1997 and 2009 in each insurance group (Medicare: adjusted odds ratio [AOR]=3.30, 95% confidence interval [CI]=1.84- 5.92; Medicaid: AOR=2.97, CI = 2.01-4.40; dually eligible for Medicare and Medicaid: AOR=2.24, CI=1.11-4.54; and private coverage: AOR=6.63, CI=5.23-8.42). The odds of antidepressant use after implementation of Part D increased more among Medicare beneficiaries than among Medicaid beneficiaries (AOR=1.35, CI=1.05- 1.72). Conclusions: The use of antidepressants among people with depression increased in all insurance groups up to 2009; however, the patterns of utilization and the degree of increase over time differed by insurance type.