Tardive dyskinesia and informed consent: myths and realities.

Tardive dyskinesia is a potentially irreversible neurologic syndrome secondary to long-term neuroleptic drug use. It is characterized by slow. rhythmical. automatic stereotyped movements particularly in the buccolingual masticatory area. extremities. and trunk muscles in patients who have received neuroleptic drugs for at least three months. Unlike other neurologic side effects to neuroleptic drugs, tardive dyskinesia is resistant to treatment with anticholinergic drugs. There is no generally effective treatment of tardive dyskinesia. I The prevalence of tardive dyskinesia varies widely in different studies but most likely is in the range of 10 to 20 percent of patients on maintenance neuroleptics. Of the total to to 20 percent of patients with tardive dyskinesia, less than to percent of them have severe abnormal movements with a fourth to a third of patients with the disorder showing moderately severe movements. While early studies suggested as many as 60 percent of cases of tardive dyskinesia were irreversible, more recent studies are more optimistic that frequent reversibility may be possible with early detection and discontinuation or reduction of neuroleptic medication. Confounding the detection and management of tardive dyskinesia is the fact that the very cause of the syndrome, neuroleptic drugs, also serves to mask it. Thus tardive dyskinesia is frequently not detected until the drugs are stopped or the dosage reduced. It is not clear what the relationship is between so-called withdrawal emergent dyskinesias and tardive dyskinesia that appears on a steady dose of neuroleptic. I However, it is clear that tardive dyskinesia is today a major public health issue in psychiatry.2 We are talking about a sometimes irreversible. sometimes severe, sometimes grotesque neurologic disorder induced by longterm exposure to what is currently the best and. to many minds, the only effective treatment for schizophrenia. It is no small wonder then that tardive dyskinesia has aroused a great deal of concern in the psychiatric community. Some have attempted to deny its existence, its irreversibility or its etiologic connection to neuroleptic