Antidepressant Treatment Outcomes of Psychogenic Movement Disorder

Background: Psychogenic movement disorder (PMD) is a subtype of conversion disorder. We describe the outcomes of a series of PMD patients following antidepressant treatment.

Method: Twenty-three outpatients with chronic PMD, diagnosed using Fahn and Williams’ criteria, underwent psychiatric assessment. The patients were referred for assessment and management from January 2003 to July 2004. Fifteen agreed to be treated with antidepressants. Patients received citalopram or paroxetine; those who did not respond after 4 weeks of taking an optimal dose were switched to venlafaxine. Concurrently, 3 had supportive psychotherapy, and 1 had family intervention. Assessments included the DSM-IV-based Mini-International Neuropsychiatric Interview and scales measuring depression, anxiety, and motor and global severity.

Results: Eighteen patients (78%) had at least 1 Axis I diagnosis in addition to the somatoform diagnosis, and 3 (13%) had somatization disorder. Five (22%) had previous psychiatric contact. Nine (39%) had previously been treated with antidepressants, but only 4 (17%) had adequate trials. No significant differences existed in patient characteristics between treated and untreated groups. Among treated patients, Montgomery-Asberg Depression Rating Scale scores improved from baseline (p < .01). Two treated subgroups were identified: 10 patients (67%) had primary conversion disorder, of whom 8 had marked motor and global improvements with 7 complete remissions, and 5 (33%) had primary hypochondriasis, somatization disorder, or probable factitious disorder/malingering, of whom none improved. All of the patients with primary conversion disorder had a current or previous depressive or anxiety disorder compared with 40% (N = 2) of the patients with additional somatoform diagnoses.

Discussion: Our preliminary findings suggest that chronic PMD with primary conversion symptoms and with recent or current depression or anxiety may respond to antidepressants. Further well-designed studies, now under way, are required to confirm these findings.