Real-World Treatment Patterns, Outcomes, Resource Utilization and Costs in Treatment-Resistant Major Depressive Disorder: PATTERN, a Retrospective Cohort Study in Belgium.

Objective: Treatment-resistant depression (TRD), a subgroup of major depressive disorder (MDD) that does not adequately respond to treatment, has a substantial impact on the quality of life of patients and is associated with higher medical and mental health care costs. This study aimed to report real-world treatment patterns, outcomes, resource utilization, and costs in the management of TRD by psychiatrists in Belgium.

Methods: We conducted a retrospective, non-interventional cohort study of patients ≥ 18 years, with diagnosed MDD who are treatment-resistant, defined as not responding to two different antidepressant treatments in the current moderate to severe major depressive episode (MDE). Data obtained from medical records of patients included patient health state (MDE, response, remission, and recovery) and resource use (number of consultations and emergency room visits, non-drug and drug interventions, and hospitalizations).

Results: One hundred and twenty-five patients were enrolled in nine sites, with an average observation period of 34 months. During the MDE, 89.7% of patients were treated with selective serotonin reuptake inhibitors, 63.2% with serotonin-norepinephrine reuptake inhibitors, and 60.8% with anti-psychotics. Twenty-four percent of patients did not respond to any treatment; 76% responded, of whom 61% experienced a relapse; 28% of patients reached recovery, of whom 31.4% experienced recurrence. The average yearly direct cost of a TRD patient is €9012, mainly driven by hospitalization in the MDE. The observed absenteeism relates to a high indirect cost, representing 70% of the total MDE cost.

Conclusion: TRD is associated with a high unmet need and economic burden for patients and society, with highest costs in the MDE health state driven by absenteeism.