Quality of life: the ultimate outcome measure of interventions in major depressive disorder.

BACKGROUND Quality-of-life (QOL) assessment and improvement have recently been recognized as important components of health care, in general, and mental health care, in particular. Patients with major depressive disorder (MDD) have a significantly diminished QOL. METHODS Using a Medline search of relevant keywords for the past 26 years, this article reviews the empirical literature to provide information regarding QOL measurement, impairment, impact of comorbidity, and treatment effects in MDD. RESULTS Studies showed that QOL is greatly affected by depression. Severity of depression is also a major contributor to further reduction in QOL when depression is comorbid with other psychiatric and medical disorders. Treatment for MDD has been shown to improve QOL in the acute treatment phase, but QOL remains low compared to healthy controls even when symptoms are in remission following treatment. CONCLUSIONS Patients with MDD suffer from poor QOL even after reduction of symptom severity. Clinicians should therefore include QOL assessment as an important part of treating depression. More research is needed to examine the factors contributing to poor QOL in MDD and to develop interventions to ameliorate it. Additionally, future treatment studies of MDD with or without comorbid disorders should track QOL as the ultimate outcome measure of treatment success.