Introduction: There is little evidence regarding the most effective timing of augmentation of antidepressants (AD) with antipsychotics (AP) in patients with major depressive disorder (MDD) who inadequately respond to first-line AD (inadequate responders). The study's objective was to understand the association between timing of augmentation of AD with AP and overall healthcare costs in inadequate responders.
Methods: Using the Truven Health MarketScan® Medicaid, Commercial, and Medicare Supplemental databases (7/1/09-12/31/16), we identified adult inadequate responders if they had one of the following indicating incomplete response to initial AD: psychiatric hospitalization or emergency department (ED) visit, initiating psychotherapy, or switching to or adding on a different AD. Two mutually exclusive cohorts were identified on the basis of time from first qualifying event date to first date of augmentation with an AP (index date): 0-6 months (early add-on) and 7-12 months (late add-on). Patients were further required to be continuously enrolled 1 year before (baseline) and 1 year after (follow-up) index date. Patients with schizophrenia or bipolar disorder diagnoses were excluded. General linear regression was used to estimate adjusted healthcare costs in the early versus late add-on cohort, controlling for baseline demographic and clinical characteristics, insurance type, medications, and ED visits or hospitalizations.
Results: Of the 6935 identified inadequate responders, 68.7% started an AP early and 31.3% late. At baseline, before AP augmentation, patients in the early add-on cohort had higher psychiatric comorbid disease burden (47.3% vs. 42.5%; p < 0.001) and higher inpatient utilization [mean (SD) 0.41 (0.72) vs. 0.27 (0.67); p < 0.001] than in late add-on cohort. During follow-up, the adjusted total all-cause healthcare cost was significantly lower in the early vs. late add-on cohort ($18,864 vs. $20,452; p = 0.046).
Conclusion: Findings of this real-world study suggest that, in patients with MDD who inadequately responded to first-line AD treatment, adding an AP earlier reduces overall healthcare costs.
Funding: Otsuka Pharmaceutical Development and Commercialization, Inc. and Lundbeck.
Keywords: Antipsychotics; Augmentation therapy; Healthcare costs; Major depressive disorder; Neurology.