The association between physical illness and major depressive episode in general practice

Physical illness and depression are associated. However, it remains unclear whether this association is sufficiently strong to merit systematic screening for depression among primary care patients suffering from physical illness. In the present study, we investigated the strength of the association between physical illness and depression among patients in general practice.

Four thousand two hundred and seventy-one consecutive primary care patients completed a diagnostic depression questionnaire. The general practitioner evaluated the patients' physical health, which was then compared to their diagnostic status of depression.

Physical illness was associated with the presence of depression. Two hundred and thirty-six patients (5.5%) fulfilled diagnostic criteria for depression. Fourteen of these suffered from extreme physical illness, 27 from at least severe physical illness and 96 from at least moderate physical illness. The number needed to screen decreased with increasing severity and chronicity of the physical illness.

Depression is relatively common in primary care patients suffering from physical illness, particularly if the illness is severe and chronic. However, relatively few depressed patients suffer from a comorbid physical illness. Screening for depression among patients with physical illness may therefore only have a modest impact on the under-recognition of depression in general practice.