Economic burden of treatment-resistant depression among veterans in the United States.

Objective: Evidence is limited on the economic burden associated with treatment-resistant depression (TRD) among US veterans. We evaluated the economic burden among patients with major depressive disorder (MDD) with and without TRD, and those without MDD in the Veterans Health Administration (VHA).

Methods: Three cohorts were identified using VHA claims data (01APR2014-31MAR2018). Patients with MDD (aged ≥18) who failed ≥2 antidepressant treatments of adequate dose and duration were defined as having TRD; patients with MDD not meeting this criterion constituted the non-TRD MDD cohort (index: first antidepressant claim). The non-MDD cohort included those without MDD diagnosis (index: randomly assigned). Patients with psychosis, schizophrenia, manic/bipolar disorder, or dementia in the 6-month pre-index period were excluded. Patients with non-TRD MDD and non-MDD were matched 1:1 to patients with TRD based on demographic characteristics (age, gender, race, index year). Health care resource utilization (HRU) and costs were analyzed during the post-index period using a negative binomial model and ordinary least squares regression model, respectively.

Results: After 1:1 exact matching, 10,449 patients were included in each cohort (mean age: 48.9 years). Patients with TRD had higher per patient per year (PPPY) HRU than non-TRD MDD (all-cause inpatient visits: incidence rate ratio [IRR]: 1.70 [95% confidence interval: 1.57-1.83]) and non-MDD (IRR: 5.04 [95% confidence interval: 4.51-5.63]), and incurred higher total all-cause health care costs PPPY than non-TRD MDD (mean difference: $5,906) and non-MDD (mean difference: $11,873; all <.0001).

Conclusion: Among US veterans, TRD poses a significant incremental economic burden relative to non-TRD MDD and non-MDD.