Diagnosing depression in patients with physical diseases using the beck depression inventory (BDI)

Four-hundred-and-forty-three patients with a physical illness (355 with coronary heart disease and 88 with chronic pain), 150 unemployed persons and 623 subjects from the normal population in Jämtland, Sweden were tested using the BDI (Beck Depression Inventory). The aim of the study was to investigate whether scores on both the physical and non-physical components of the BDI differed between the patients and the other groups, or whether only the physical component was significantly higher in the patient group, and in such a case whether this could be interpreted as symptomatic of physical disease and not of depression. A cutoff score of ≥ 10 to determine mild depression and two different alternative physical and non-physical components were used. Forty-three percent of the patients with coronary heart disease and 50% of patients with chronic pain were categorized as being at least mildly depressed. Factor analyses indicated that a physical component comprising five items was the most meaningful and could best discriminate the physical symptoms. The patients' scores were significantly higher than those of the other two groups on the physical component but only higher than the normal population sample on the nun-physical component. This supports the idea that the items for physical symptoms in the BDI might be confounding when determining depression in patients with physical diseases. The non-physical component seems to be the best indicator of depression and is recommended as a complement to the total BDI scale when determining the degree of depression in patients suffering from a physical disease.