Chinese patients with major depression. Do concomitant pain symptoms affect quality of life independently of severity of depression?

Objective. This study investigated whether painful physical symptoms (PPSs) influenced quality of life (QoL) when adjusting for severity of depression. Methods. Severity of depression, QoL and PPSs were assessed at baseline and 3 months among the Chinese cohort (n = 300) of a 3-month observational study of major depressive disorder (MDD) in East Asia. The presence of PPS was defined as a mean score of ≥2 on the Somatic Symptom Inventory pain-related items. Regression analyses determined predictors of QoL at 3 months, adjusting for age, sex, depressive symptoms, overall severity and QoL at baseline. Results. PPSs were present (PPS+) at baseline in 35.3% of patients. Over 3 months, in the whole sample, EuroQoL visual analogue scale (EQ-VAS) score improved from 45.5 (standard deviation [SD]: 20.9) to 81 (SD: 16.7), and EuroQoL 5-Dimension Questionnaire (EQ-5D) score improved from 0.52 (SD: 0.31) to 0.89 (0.16). At 3 months, mean EQ-VAS was 75.9 (SD: 17.7) for PPS+ versus 83.7 (SD: 15.6) for PPS-, and mean EQ-5D was 0.83 (SD: 0.17) versus 0.92 (SD: 0.14). PPS+ at baseline was a significant predictor of QoL at 3 months after adjusting for socio-demographic and baseline clinical variables. Conclusions. PPSs were associated with less improvement in QoL in patients receiving treatment for MDD, independent of severity of depression.