Clinical criteria for diagnosing conversion disorders

Conversion disorder proper consist of a loss or impairment of bodily function which mimics the symptomatology of a ''genuine'' organic illness. In clinical settings, it is often difficult to diagnose a conversion disorder. In this paper, empirical studies are reviewed where the validity of psychological or psychopathological criteria for the diagnosis of conversion disorder has been tested. Furthermore, the results of a study are presented, where all patients consecutively admitted for various psychogenic disorders were screened for conversion disorder. Of those, 22 patients met the DMS-III-R criteria for conversion disorder. After excluding a somatic origin of their complaints they were given a psychiatric examination and evaluated for sociodemographic data and personality traits. The results are discussed in the context of the reviewed studies. Although the data are limited to a comparatively small group of patients, some preliminary conclusions can be drawn: Conversion disorders are heterogeneous in regard to phenomenology and course. No specific psychopathological characteristics or personality traits could be determined. Thus, it seems advisable to follow the interpretation of conversion phenomena as symptoms rather than as independent psychiatric disorders. The most valid and reliable criterium of diagnosis is the impossibility to reconcile symptoms with anatomy and pathophysiology. In difficult cases, evidence of previous symptoms without a somatic explanation may be of additional help. Diagnosis of a conversion disorder can probably be regarded as definite if the symptom has occurred repeatedly under emotional stress or if the symptomatology remits lastingly after psychotherapy.