Affective and cognitive rather than somatic symptoms of depression predict 3-year mortality in patients on chronic hemodialysis

Depression is more common in many medical conditions than among the general population and is associated with an increased risk of mortality. We aimed to determine whether somatic symptoms of depression were more predictive of mortality than affective and cognitive symptoms in hemodialysis patients. We conducted a prospective cohort study in which the survival outcomes of 151 subjects were followed for more than 3 years. Depression was assessed with the Taiwanese Depression Questionnaire (TDQ). Subjects with TDQ scores 19-54 (correlated with clinically significant depressive symptoms) and those with scores 15-18 had higher 3-year mortality rates than the two groups with lower scores (40.0%, 46.7%, 16.0% and 19.6%, p = 0.021, ANOVA). Affective and cognitive symptoms, including sadness, tenseness, indecisiveness and low self-confidence, and one somatic item (bodily discomfort) were associated with mortality. Affective and cognitive symptoms affected quality of life more than somatic symptoms. The somatic subscale was associated with female gender, low income and education, dialysis vintage, and low serum creatinine and albumin levels, whereas the affective and cognitive subscale was associated with less education and a low serum albumin level. In conclusion, affective and cognitive symptoms of depression may better predict long-term mortality in patients undergoing chronic hemodialysis than somatic symptoms.