Quality of life across domains among individuals with treatment-resistant depression

Abstract

BackgroundTreatment-resistant depression affects millions of people worldwide and is a leading cause of disability and suicide. Studies of treatment-resistant depression outcomes have traditionally focused on depressive symptoms and functional impairment. Quality of life (QoL) has not been well described. We aimed to measure QoL in individuals with treatment-resistant depression and to determine how QoL was related to traditional measures of symptoms and social functioning. MethodsWe used a reliable, cross-culturally validated questionnaire, the abbreviated World Health Organization Quality of Life scale (WHOQOL-BREF), to prospectively measure QoL in 79 patients with treatment-resistant depression who were referred for electroconvulsive therapy at a United States tertiary-care medical center. QoL was characterized in four domains: physical, psychological, social, and environmental. QoL domains were examined for association with demographic variables, patient-reported depressive symptoms, functional impairment, and childhood adversity, as well as clinician-rated scales. ResultsRelative to published international norms, mean QoL scores were low in physical (standardized score, z = –2.0), psychological (z = –2.6), and social (z = –1.0) domains, but not in the environmental domain (z = 0.2). After controlling for age and income, patient-rated depressive symptoms correlated with physical (Pearson correlation, r = –0.26) and psychological (r = –0.43) QoL, whereas adverse childhood experiences correlated with environmental QoL (r = –0.33). Patient-rated functional impairment correlated modestly with all domains (r = –0.25 to –0.39). Surprisingly, QoL correlated very weakly with clinician-rated measures. These modest associations of QoL with other clinical scales were confirmed in multiple regression analyses. LimitationsWe used a single QoL instrument, which did not allow us to directly compare the WHOQOL-BREF scale with other commonly used instruments. Our sample was recruited from a single academic medical center in the Midwest region of the United States and was largely Caucasian. These factors may limit generalizability to other settings and ethnicities. ConclusionAmong individuals with treatment-resistant depression, QoL is lowest in the psychological and physical domains. QoL is only modestly correlated with patient-rated symptoms and functioning, and even more weakly correlated with clinician-rated scales, indicating that measures of symptoms and functioning cannot serve as QoL proxies. QoL should be assessed when caring for patients with treatment-resistant depression. When developing novel biological, psychological, and social interventions for treatment-resistant depression, QoL should be targeted as a distinct clinical outcome.