Physical symptom attributions: a defining characteristic of somatoform disorders?

We examined whether primary care patients were more likely to perceive a current health problem as 'physical illness only' as opposed to entailing psychological difficulties if they had a comorbid somatoform disorder compared to patients who had (a) both comorbid somatoform disorder and anxiety/depression or (b) comorbid anxiety and/or depression, and a reference group of (c) patients with well-defined physical disease. We examined whether attributions predicted future health expenditures.

A total of 1209 of 1785 patients completed questions on patient-perceived illness. The physicians diagnosed the current health problem. A stratified subsample was interviewed using the Schedules for Clinical Assessment in Neuropsychiatry. Health expenditure was obtained from registers for a 2-year period.

The belief that the current health problem was only physical was endorsed by 86% of patients presenting physical disease, 58% of patients with somatoform disorders, 29% of patients with both somatoform disorders and anxiety/depression and 24% of patients with anxiety or depressive disorders (χ2=269.2, df=3, P<.0001). In a multiple regression model, a 'physical illness only' perception predicted lower health expenditures [β = -0.31, 95% confidence interval (-0.55; -0.07), P=.013].

The prevalent assumption that physical symptom attributions are a central aspect in somatoform disorders is not supported by the current study.