Recognition and differential diagnosis of tardive dyskinesia.

Tardive dyskinesia (TD) is a consequence of chronic neuroleptic therapy. It is an irregular stereotyped movement disorder that is usually choreic in appearance, and is subject to temporary volitional control. Dystonia, akathisia, and tics are uncommon variants of the classic tardive syndrome. Characteristic clinical features including amelioration by action, augementation by distraction, partial volitional suppressibility, and lack of subjective distress help differentiate TD from other movement disorders such as resting tremor, Huntington's disease, spontaneous dyskinesias, and abnormal movements accompanying psychiatric illnesses.