The relationship between quality of life and clinical phenotype in patients with treatment resistant and non-treatment resistant depression.

OBJECTIVE: The purpose of this investigation is to determine the differences in quality of life (QOL) and clinical phenotype between patients with treatment resistant (TRD) and non-treatment resistant depression (NTRD).

PATIENTS AND METHODS: The severity, QOL, and cognitive function of 107 TRD and 173 NTRD patients were evaluated and calculated by the Hamilton Depression Scale-17 (HAMD-17), the 36-Item Short Form Health Survey (SF-36), and the P300 component of event-related potentials (ERP), respectively.

RESULTS: The scores of HAMD-17 showed no significant statistical differences between TRD (28.8±6.7) and NTRD patients (29.3±8.2). The scores of anxiety/somatization (t=4.535, p=0.002), core item (t=3.514, p=0.005) and sleep item (t=6.079, p=0.000) were statistically significantly higher in TRD patients than in NTRD patients. The scores of physiological function (75.46±20.1, 88.23±21.4), body pain (61.39±17.1, 77.19±21.2) and social functioning (40.27±20.6, 58.82±22.1) in SF-36 were statistically significantly lower in TRD patients than in NTRD patients. The P300 latency of ERP was statistically significantly longer in TRD patients than in NTRD patients. Each item in the quality of life was negatively related to the items in HAMD-17 in TRD patients, especially for anxiety/somatization, and sleep items. The QOL was negatively related to core item and retardation item in NTRD patients, and the QOL was negatively related to the P300 latency of ERP in both groups, p<0.05. The sleep disorder, anxiety/somatization and core items were more serious in TRD patients than in NTRD patients, when the severity of depression was not significantly different. The QOL was significantly lower in TRD patients than in NTRD patients, the anxiety/somatization and sleep disorder were the main symptomatic factors that caused decreased QOL in TRD patients.

CONCLUSIONS: The abilities of abstract generalization, thinking transfer, and performing a function, were significantly lower in TRD patients than in NTRD patients, which were important factors which caused decreased QOL in TRD patients.