Somatization increases disability independent of comorbidity.

BACKGROUND: Somatoform disorders are an important factor in functional disability and role impairment, though their independent contribution to disability has been unclear because of prevalent medical and psychiatric comorbidity.
OBJECTIVES: To assess the extent of the overlap of somatization with other psychiatric disorders and medical problems, to compare the functional disability and role impairment of somatizing and non-somatizing patients, and to determine the independent contribution of somatization to functional disability and role impairment.
DESIGN: Patients were surveyed with self-report questionnaires assessing somatization, psychiatric disorder, and role impairment. Medical morbidity was indexed with a computerized medical record audit. PARTICIPANTS: Consecutive adults making scheduled visits to their primary care physicians at two hospital-affiliated primary care practices on randomly chosen days. MEASUREMENTS: Intermediate activities of daily living, social activities, and occupational disability.
RESULTS: Patients with somatization, as well as those with serious medical and psychiatric illnesses, had significantly more impairment of activities of daily life and social activities. When these predictors were considered simultaneously in a multivariable regression, the association with somatization remained highly significant and was comparable to or greater than many major medical conditions.
CONCLUSIONS: Patients with somatization had substantially greater functional disability and role impairment than non-somatizing patients. The degree of disability was equal to or greater than that associated with many major, chronic medical disorders. Adjusting the results for psychiatric and medical co-morbidity had little effect on these findings.