A randomised controlled clinical trial on the additional effect of hypnosis in a comprehensive treatment programme for in-patients with conversion disorder of the motor type

Background: The primary aim of this study was threefold: (1) to examine the additional effects of hypnosis aimed at symptom reduction, using symptom-oriented and expression- and insight-oriented techniques in a comprehensive clinical treatment programme for in-patients with a persistent conversion disorder of the motor type; (2) to assess whether the level of hypnotisability was predictive of treatment outcome, and (3) to explore the efficacy of the total clinical treatment programme.

Methods: The study population consisted of 45 in-patients between 18 and 65 years of age meeting the DSM-III-R criteria for conversion disorder of the motor type or somatisation disorder with motor conversion symptoms. A randomised controlled clinical trial was undertaken. The primary outcome measures were the Video Rating Scale for Motor Conversion Symptoms, the D(isabilities) code items from the International Classification of Impairments, Disabilities and Handicaps and the Symptom Checklist-90. Measures of the credibility of treatment and patient expectations of treatment outcome were used as manipulation checks. Hypnotisability was measured using the Stanford Hypnotic Clinical Scale.

Results: Significant treatment results for all outcome measures were found for the total sample. These effects proved to be clinically significant. The use of hypnosis had no additional effect on treatment outcome. Hypnotisability was not predictive of treatment outcome.

Conclusion: A comprehensive treatment programme, either with or without hypnosis, can be worthwhile for patients with long-standing conversion symptoms.