Treatment patterns, health care resource utilization, and costs associated with use of atypical antipsychotics as first vs subsequent adjunctive treatment in major depressive disorder

BACKGROUND: Major depressive disorder (MDD) is a highly prevalent mental health condition associated with substantial economic burden. Inadequate response to first-line antidepressant monotherapy is common, with most patients requiring 1 or more changes in their treatment regimen. Adjunctive treatment with atypical antipsychotics (AAs) is a guideline-recommended treatment option in patients with inadequate response. However, patients often cycle through multiple treatments before receiving adjunctive AAs, and the economic impact of this delay is unknown. OBJECTIVE: To describe adjunctive treatment patterns among patients with MDD and compare health care resource utilization (HCRU) and costs between patients whose first adjunctive therapy included an AA and those who received an AA after other adjunctive treatments. METHODS: The Merative MarketScan Commercial Database (January 1, 2014, to June 30, 2019) was used to identify patients with administrative claims meeting the following inclusion criteria: adults with newly diagnosed MDD (first observed MDD diagnosis = index diagnosis date); continuous health insurance for at least 6 months preindex and at least 3 months post-index; and initiation of MDD treatment within 60 days post-index. Lines of therapy (LOTs), HCRU, and costs were analyzed in patients who received AA adjunctive therapy, including those who initiated AAs as the first adjunctive treatment and those who initiated AAs as subsequent adjunctive treatment. RESULTS: Of 508,830 patients meeting inclusion criteria, 121,060 (24%) received adjunctive treatment and 20,797 (4%) received an AA as adjunctive therapy. Mean time to adjunctive therapy initiation was approximately 7.3 months for AA adjunctive therapy. Patients who initiated an AA as their first adjunctive therapy compared with patients who initiated an AA as their subsequent adjunctive therapy had fewer LOTs on average (0.9 LOTs vs 3.9 LOTs) and shorter time between index diagnosis date and initiation of an AA (5 months vs 12 months). Subsequent AA initiators had significantly greater HCRU than first AA initiators (driven primarily by outpatient visits) and incurred significantly higher total health care costs, with mean all- cause and mental health-related health care cost differences per patient per year of $2,441 and $1,762, respectively (both P < 0.05). CONCLUSIONS: Less than 5% of patients in this study received an adjunctive AA as part of their MDD treatment regimen, suggesting underutilization of this recommended therapeutic approach. Patients who received an AA as their first adjunctive treatment regimen had lower HCRU and health care costs than subsequent AA initiators. Along with published evidence of clinical benefits, this potential impact on economic burden should be considered when making treatment choices for patients with inadequate response to antidepressants.