Lack of specificity of the traditional criteria for conversion disorders.

Psychological and physical signs traditionally considered as indicators of conversion disorder had never been confirmed through empirical data. Nineteen of these signs were sought in 40 patients with proved neurological disorder and in 15 patients with conversion disorder. All neurological patients but one showed at least one of these signs and most presented several signs. All the signs but one were as frequent in neurological patients as in patients with conversion disorder. These signs are lacking specificity. Even when several signs are present, this finding has no diagnostic specificity.