Construct validity and clinical utility of current research criteria of DSM-5 somatic symptom disorder diagnosis in patients with fibromyalgia syndrome.

OBJECTIVE: The validity and clinical utility of current research criteria of the DSM 5 category somatic symptom disorder (SSD) needs to be tested outside the setting of psychiatry.

METHODS: Consecutive patients with an established diagnosis of fibromyalgia syndrome (FMS) were evaluated by medical examination, psychiatric interview and self-report questionnaires in an outpatient pain medicine center. The diagnosis of SSD was established using published research criteria. The discriminative concurrent criterion validity of SSD was tested by comparing FMS-patients with and without SSD as to the amount of impairment and of health care seeking. Two clinicians blinded as to the purpose of the study, assessed the medical reports of patients after the evaluation for the determination of the need for psychotherapy based on the German FMS - guideline recommendations (clinical utility).

RESULTS: 25.6% of 156 patients met the criteria of SSD. Patients meeting SSD criteria scored significantly higher in a self-report measure of disability. There were no significant differences in the number of patients on sick leave or applying for disability pension and in self-reported doctor visits and physiotherapy in the previous six months. 95.0% of patients with SSD and 71.6% of patients without SSD met the criteria of a current anxiety or depressive disorder as assessed by the psychiatric interview. 80.0% of patients with SSD and 66.7% of patients without SSD received a recommendation for psychotherapy.

CONCLUSIONS: The construct validity and clinical utility of current research criteria of DSM 5 category SSD were limited in German patients with FMS.