Depression, disease and disability: application to patients with traumatic spinal cord injury.

Depressive symptoms are common in medically ill patients. Methodological difficulties of many of the studies demonstrating this do not allow differentiation of depressive symptoms from depressive illness. This paper examines representative samples of studies in the medically ill to highlight these problems. Data from a study of patients with traumatic spinal cord injury are used to demonstrate (1) ways of overcoming some of these difficulties and (2) the means of differentiating depressive symptoms and depressive illness. Difficulties of detection and diagnosis of depression in the medically ill are discussed.