Functional (psychogenic) movement disorders associated with normal scores in psychological questionnaires: A case control study.

OBJECTIVE Functional movement disorders (FMDs) fall within the broader category called functional neurological symptom disorder (FNSD). New DSM-5 criteria for FNSD no longer require the presence of a 'psychological conflict' suggesting that some patients with FMD may not have obvious psychological comorbidity. We studied patients with FMD in comparison to patients with a neurological movement disorder (MD) and healthy controls (HC) to identify whether there is a subgroup of patients with FMD who have normal psychological test scores. METHODS We assessed self-rated measures of depression/anxiety (SCL-90), dissociation and personality disorder (PDQ-4) in patients attending neurological clinics and healthy controls. The proportion of patients scoring within normal ranges was determined, and the levels of somatic and psychological symptoms were compared between the three groups. RESULTS Among the FMD group, 39% (20/51) scored within the normal range for all measures compared to 38% (13/34) of MD subjects and 89% (47/53) of healthy controls. There were no differences in overall scores in the SCL-90 and PDQ-4 between FMD and MD patients. FMD patients also did not differ from controls on a self-rated measure of personality pathology. CONCLUSION Our data show that a substantial proportion of patients with FMD score within the normal range in psychological questionnaires, lending some support to the new DSM-5 criteria.