OBJECTIVES: To examine the humanistic and economic burden of treatment-resistant depression (TRD) in Europe.

METHODS: A retrospective, cross-sectional analysis was performed using data from the 2017 Europe National Health and Wellness Survey. Amongst patients with major depressive disorder (MDD) (included: self-reported physician-diagnosed depression and currently taking ≥1 medication for depression; excluded: anticonvulsant/antipsychotic monotherapy, bipolar disorder, or schizophrenia), TRD was identified as ≥2 anti-depressant medications (≥3 months), or monoamine oxidase inhibitor monotherapy, or reported they did not respond to previous therapy, and moderate/severe depressive symptoms (PHQ-9 ≥10). TRD patients were compared to (1) non-TRD MDD 'nTRD' and (2) general population controls (without a diagnosis of depression). Outcomes including health-related quality of life (HRQoL) (SF-12v2, EQ-5D), Work Productivity and Activity Impairment (WPAI), and healthcare resource utilization (HRU) were assessed using generalized linear models adjusted for covariates. Differences between TRD and control groups were examined using adjusted differences (AD) or relative risks (RR) and 95% confidence intervals (CI).

RESULTS: Our study compared 622 TRD patients to 2686 nTRD patients and to 48,852 healthy controls. TRD compared to nTRD patients reported significant decrements in HRQoL, including the mental (AD=-5.65, 95% CI= -6.50–-4.81) and physical (AR=-2.27, 95% CI= -3.13–-1.41) component scores of the SF-12v2 and EQ-5D (AD=-0.13, 95% CI=-0.16–-0.11), increased in healthcare provider visits (RR=1.54, 95% CI=1.40–1.69), emergency department visits (RR=1.66, 95% CI=1.42–1.95), and hospital admissions (RR=1.47, 95% CI=1.20–1.79). All WPAI scores were higher for TRD than nTRD including, work productivity (RR=1.29, 95% CI=1.12–1.50) and overall activity (RR=1.28, 95% CI=1.17–1.40). Even greater differences were observed for all outcomes when compared to the general population (all statistically significant, p<0.05).

CONCLUSIONS: These results suggest that TRD represents a substantial additional burden even within the MDD population by having significant impact on quality of life and costs related to work and activity loss and HRU.