Ezrin-Waters C, Seeman M V, Seeman P
J Clin Psychiatry. 1981 Jan;42(1):16-22.
All the patients (N = 94) of an outpatient clinic for schizophrenia were evaluated for the presence and severity of neuroleptic induced tardive dyskinesia. Fourty-four percent of the patients showed some degree of tardive dyskinesia. The proportion of patients with tardive dyskinesia increased directly with age and with number of years of neuroleptic treatment. Recent dose reduction exacerbated the syndrome. There were no gender differences in the clinic as a whole. Severity of dyskinesia correlated with anticholinergic drug use, with the piperazine/butyrophenone group of neuroleptics and with the use of depot-administered drugs. The depot correlation was highly significant in the under-30 age group.