Predictors of improvement in tardive dyskinesia following discontinuation of neuroleptic medication.

Forty-nine chronic psychiatric out-patients (ten were schizophrenic) with tardive dyskinesia (TD) were examined monthly for a mean of 40 weeks (range 1-59 months) after discontinuation of neuroleptic medication. Complete and persistent reversibility of TD was rare (2%), but many patients showed noticeable improvement in movements within the first year of discontinuation, which was sometimes interrupted by psychological relapse. Using three separate outcome measures and appropriate model-fitting techniques for each, we identified several predictors of improvement in TD, including an affective or schizoaffective psychiatric diagnosis, chronic (over 20 years) psychiatric illness, being employed, younger age, and increased neuroleptic dose before discontinuation. Consistent findings emerging from these analyses suggest that the type and history of psychiatric illness affect the course of TD.