A prospective study to determine the association between physical symptoms and depression in patients with advanced cancer

Abstract

Depression is a common symptom in patients with advanced cancer and patients who are depressed may also have physical symptoms which are difficult to palliate and which improve as their depression is appropriately treated. This study was carried out to determine if there was an association between depression and physical symptoms in patients with advanced cancer and to establish whether a seven-item verbal rating scale asking patients to verbally rate the severity of physical symptoms together with low mood could be used to screen for depression. The scale was validated against a semi-structured clinical interview according to DSM IV criteria. Seventy-four patients participated with an age range of 28–92 years. All patients had an ECOG performance status of two or three. The prevalence of major depression in this study was found to be 27% (95% C.I. 17–37%). The mean score on the verbal rating scale was 28.77 (median score 29.5) (95% C.I., 26.23–31.31; range 0–65). A cut-off of ≥30 gave a sensitivity of 65% and specificity of 59%, with positive and negative predictive values of 37% and 82% respectively. The verbal mood item alone had an optimal cut-off point of 3, with a sensitivity of 80% and specificity of 43%. Patients diagnosed as being depressed according to psychiatric interview rated each symptom higher than nondepressed patients. The verbal mood item and total verbal rating score correlated with a high significance (rs=0.607, P<0.01), implying a relationship between a patient's subjective mood state and other symptoms. Both using the verbal scale and asking patients to verbally rate their mood alone had poor efficacy as a screening tool. However, there is a close association between physical symptoms and the presence of depression in palliative care patients.