The motor disorders of severe psychiatric illness: a conflict of paradigms.

The motor disorder of 100 patients with severe psychiatric illness is described and the contribution of previous treatment, hospitalization and possible neurological disorder is considered. The conflict of paradigms between the concept that this motor disorder has two distinct aetiologies, psychiatric and neurological, and the concept that both motor and mental disorder are an expression of underlying cerebral disorder is discussed. An attempt is made to resolve this conflict by description of motor disorder without reference to neurological or psychiatric diagnosis.