The mediating effects of depression on sleep disturbance and fatigue: symptom clusters in patients with hepatocellular carcinoma.

The purposes of this study were to (a) explore the relationships among sleep disturbance, fatigue, and depression and (b) test whether depression mediates the effect of sleep disturbance on fatigue in patients with hepatocellular carcinoma (HCC). A cross-sectional study was conducted with a total of 77 patients with HCC. All participants completed questionnaires that included the Brief Fatigue Inventory-Taiwan Form, the Pittsburgh Sleep Quality Index-Taiwan Form, and the depression subscale of the Taiwanese version of the Hospital Depression and Anxiety Scale. Path analysis was used to test the mediation role of depression. Fatigue, sleep disturbance, and depression are positively interrelated and co-occur in patients with HCC. Moreover, depression completely mediates the effects of sleep disturbance on fatigue. These findings suggest that depression is an important mechanism underlying the relationship between sleep disturbance and fatigue for patients with HCC. This is the first study to explore the phenomenon of symptom clustering in sleep disturbance, fatigue, and depression in patients with HCC and to investigate the mediating role of depression that underlies the relationship between sleep disturbance and fatigue. The current findings are of clinical importance because they suggest the need to consider simultaneous management of sleep disturbance, fatigue, and depression.