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

BACKGROUND

Treatment-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.

METHODS

We 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.

RESULTS

Relative 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.

LIMITATIONS: We 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.

CONCLUSION

Among 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.