OBJECTIVES: Treatment-resistant depression (TRD) is characterized by an inadequate response of treatment within a specified time period. It is anticipated that the costs related to TRD are much greater compared to other types of depression. This review aims to summarize recent literature on epidemiology, healthcare resource utilization and direct and indirect costs of TRD.

METHODS: A targeted literature search of English publications from May 2009 to May 2019 was performed in PubMed, Cochrane Library and Embase databases.

RESULTS: Thirty articles were included in the review. The prevalence of TRD among patients diagnosed with depression varied from 13% (Denmark) to 55% (United Kingdom). Sixteen studies indicated a positive association between TRD and inpatient and outpatient visits. Annual health care costs for patients with TRD were much higher than for patients with other forms of depression. Average annual per person costs varied across studies from USD 3,075 (Brazil) to USD 24,543 (United States). Overall, patients with TRD incur significant annual healthcare expenditure. There was limited evidence on incidence (n=3), mortality (n=1) and indirect costs (n=4) of TRD. Additionally, the study results are limited by inconsistencies in definitions of TRD across studies.

CONCLUSIONS: The burden imposed by TRD on patients, payers, and society is considerable. However, due to limited availability of evidence, further studies are required to fully assess the overall burden of this disease.