OBJECTIVE: To examine the clinical characteristics of individuals with schizophrenia that develop tardive dyskinesia (TD) associated with antipsychotic treatment.
METHODS: Baseline data on 1460 patients with schizophrenia were collected as part of the Clinical Antipsychotic Trials of Intervention Effectiveness schizophrenia study. Subjects who met Schooler-Kane criteria for probable TD were compared to those without TD. Multiple regression analyses were used to examine the relationship between TD and clinical variables.
RESULTS: 212 subjects met the Schooler-Kane criteria for probable TD and 1098 had no history or current evidence of TD. Subjects with TD were older, had a longer duration of receiving antipsychotic medication, and were more likely to have been receiving a conventional antipsychotic and an anticholinergic agent. After controlling for important baseline covariates, diabetes mellitus (DM) and hypertension did not predict TD, whereas substance abuse significantly predicted TD. Differences in cognitive functioning were not significantly different after controlling for baseline covariates. The TD subjects also had higher ratings of psychopathology, EPSE, and akathisia.
CONCLUSION: Our results confirm the established relationships between the presence of TD and age, duration of treatment with antipsychotics, treatment with a conventional antipsychotic, treatment with anticholinergics, the presence of EPS and akathisia, and substance abuse. Subjects with TD had higher ratings of psychopathology as measured by the PANSS. We found no support for DM or hypertension increasing the risk of TD, or for TD being associated with cognitive impairment.