Organic syndromes diagnosed as conversion disorder: identification and frequency in a study of 85 patients.

BACKGROUND The percentage of patients initially diagnosed with a conversion disorder and later identified as having an organic disorder has been decreasing in recent studies. METHOD Consecutive patients with a diagnosis of conversion disorder were referred for psychiatric diagnosis and treatment. Research questions were: (1) What incidence of neurological disorder is revealed by neurological reassessment and by which diagnostic technique is the final diagnosis established? (2) What differences can be observed between true-positive and the false-positive results? RESULTS Ten (11.8%) of the 85 patients examined appeared to suffer from a neurological disorder. In this sample, variables discriminating between the true positives and false positives were: (1) prior suspicion of neurological disorder; (2) older age at referral; (3) older age at onset of symptoms; (4) longer duration of symptoms; and (5) use of medication. Three variables contributed significantly to the prediction of organic disorder: prior suspicion of neurological disorder; age at onset of symptoms; and duration of symptoms. CONCLUSIONS Although our results are in line with those of other recent studies, the percentage of false positives was still high. The data further emphasize the dangers of making a diagnosis of conversion disorder in the absence of positive evidence. It is important to continue to provide follow up for patients with a diagnosis of conversion disorder. Unfortunately, unreliable psychiatric indications, like certain behavioral characteristics, are still used in the diagnostic process. The results show that a general neurological examination is still a valuable diagnostic instrument in addition to modern diagnostic techniques.