ObjectiveThe purpose of this study was to evaluate the treatment patterns and success rates with antidepressants utilized by patients in a managed care organization (MCO).MethodsData were extrapolated from a claims database from an MCO with 225 000 members. Treatment patterns were determined by creating episodes of care for each patient. Successful treatment was defined as a therapeutic dose for at least 180 days of continuous therapy. Success rates were stratified by the type of antidepressant used. Depression-related and total healthcare costs were analyzed in relation to whether a patient's treatment was successful.ResultsA minority of patients received continuous therapeutic doses for 180 days for their first treatment episode (26.5%) or all treatment episodes of depression (32.9%). Monotherapy was the most common treatment pattern. Treatment with a selective serotonin reuptake inhibitor (SSRI) was associated with a significantly higher success rate than treatment with a tricyclic antidepressant (TCA), in patients with depression (36.6 vs 13.3%). In patients with depression who were receiving SSRIs, the success rates were 37.2% with fluoxetine, 36.2% with paroxetine, and 36.1% with sertraline; there were no significant differences in the success rates among the SSRIs. Patients completing a successful treatment episode were associated with higher pharmacy, depression-related, and total healthcare costs.ConclusionsOnly a minority of patients with depression attained a satisfactory treatment episode with their antidepressant therapy. SSRI therapy was associated with a significantly higher success rate than TCAs. Although monotherapy regimens were the most commonly used treatment strategy, the multivariate analysis reveals that multiple regimen changes (defined as complex in this analysis) may be required to achieve successful treatment. Physicians and MCOs need to monitor patients and be open to necessary regimen changes. Physicians and MCOs must also work together to develop improved strategies to monitor and detect patients with depression who do not comply with their antidepressant regimen.