The misdiagnosis of conversion disorder in a psychiatric emergency service.

During a 1-year period, 8400 patient presentations to a psychiatric emergency service were screened for the conversion symptom of extremity paresis/paralysis. Of 4220 unduplicated presentations, three patients had this complaint. These cases were reviewed and followed up. All had received a DSM-III diagnosis of conversion disorder, but in each case the patient's conversion symptom was attributed to organic disease. This had medicolegal consequences in one case and threatened legal consequences in the others. Although the frequency of this alleged conversion symptom was 0.07%, in reality it was 0.0%. Guidelines for the management of the alleged conversion symptom of paresis/paralysis are discussed.