Medically unexplained symptoms and somatoform disorders: diagnostic challenges to psychiatrists

Clinical limitations of the criteria of somatoform disorders (SDs) have been criticized. However, little objective evidence supports this notion. We aimed to examine the prevalence of SDs in a population with medically unexplained symptoms (MUS), which was expected to have higher probabilities meriting such diagnoses, and to evaluate factors that may influence the clinical judgment of psychiatrists.

Data of subjects with MUS (n = 101, 9.5%) as their chief consulting problems, of 1,068 consecutive ethnic Chinese adult medical inpatients referred for consultation-liaison psychiatry services, were reviewed. Psychiatric diagnoses including SDs and clinical variables were collected. Those with SDs were followed-up 1 year later, and structured interviews were applied.

Patients with MUS had a high level of psychiatric comorbidity, especially depression (35.6%) and anxiety disorder (29.7%), rather than SDs (9.9%). Most diagnosed with SDs suffered from persistent MUS at the 1-year follow-up. Pain was the most common presentation of MUS. Most of the subjects diagnosed with SDs were female and younger, with multiple painful sites at presentation, no past psychiatric diagnosis and no comorbid organic diagnoses. The diagnosis of SDs was seldom given in those with simultaneous MUS and mood symptoms.

A significant proportion (9.5%) of patients in psychiatric consultation suffered from MUS, and most were comorbid with depression and anxiety. The identification of SDs was made in only 9.9%. Because MUS are associated with a high rate of mental comorbidities, psychiatric consultations while facing such clinical conditions are encouraged.