Cost-effectiveness of adjunctive therapy with atypical antipsychotics for acute treatment of major depressive disorder.

BACKGROUND

While the clinical utility of atypical antipsychotics has been established in patients with major depressive disorder (MDD) who are refractory to antidepressant therapy, their cost-effectiveness is unknown.

OBJECTIVE

To examine the cost-effectiveness of aripiprazole, quetiapine, and olanzapine/fluoxetine in adults with MDD who are refractory to antidepressant therapy.

METHODS

Using techniques of decision analysis, we estimated expected outcomes and costs over 6 weeks in adults with MDD receiving (1) aripiprazole 2-20 mg/day and antidepressant therapy; (2) quetiapine 150 mg/day or 300 mg/day and antidepressant therapy; (3) the fixed-dose combination of olanzapine 6, 12, or 18 mg/day with fluoxetine 50 mg/day; or (4) antidepressant therapy alone. Cost-effectiveness was assessed in terms of the cost per additional responder at 6 weeks, defined as the ratio of the difference in the cost of MDD-related care over 6 weeks versus antidepressant therapy alone to the difference in the number of patients achieving clinical response by 6 weeks. We estimated the model using data from Phase 3 clinical trials of atypical antipsychotics along with other secondary data sources.

RESULTS

With antidepressant therapy alone, the estimated clinical response rate at 6 weeks was 30%. Aripiprazole, quetiapine 150 mg/day, quetiapine 300 mg/day, and olanzapine/fluoxetine were estimated to increase clinical response at 6 weeks to 49%, 34%, 38%, and 45%, respectively. Costs of MDD-related care over 6 weeks were estimated to be $192 for antidepressant therapy, $847 for aripiprazole, $541 for quetiapine 150 mg/day, $672 for quetiapine 300 mg/day plus antidepressant therapy, and $791 for olanzapine/fluoxetine. Costs per additional responder (vs antidepressant therapy) over a 6-week period were estimated to be $3447 for aripiprazole, $8725 for quetiapine 150 mg/day, $6000 for quetiapine 300 mg/day, and $3993 for olanzapine/fluoxetine.

CONCLUSIONS

Atypical antipsychotics substantially increase clinical response at 6 weeks. Cost per additional responder is lower for aripiprazole than for quetiapine or olanzapine/fluoxetine.