Prevalence and risk factors for tardive dyskinesia: a study in an Italian population of chronic schizophrenics.

The aim of this study was to evaluate tardive dyskinesia (TD) (prevalence and possible risk factors, pharmacological and clinical), in a population of schizophrenic patients after prolonged institutionalization. A total of 148 patients (80 male, 68 female) aged between 28 and 87 years (mean 55, SD 11) diagnosed according to DSM III were included in the study and assessed for the presence and severity of TD using the Abbreviated Rockland Simpson Scale for TD. Of the examined population, 32% were found to be affected by TD. Patients over 55 years had a relative risk of TD that was 2.3 times higher than in subjects under 55 (P less than 0.05). The most frequent movements were orofacial (60%) and in the extremities (56.4%). No significant relationship between duration of neuroleptic treatments, illness or hospitalization, anticholinergic drugs and TD prevalence was found. Severity was related to age, since there was a positive linear relationship between age and Simpson Scale scores (r = 0.45, P less than 0.01).