Familial occurrence of tardive dyskinesia

Objective: Familial occurrence of tardive dyskinesia (TD) and schizophrenia has been hypothesized to confer risk to the development of TD. We investig ated these hypotheses in a large patient sample applying standardized metho ds for phenotype characterization. Method: Two hundred and twenty-two patients with a diagnosis of schizophren ia or schizoaffective disorder were assessed for TD and for family history of schizophrenia or schizoaffective disorder. Thirty-nine patients had 40 a ffected first-degree family members, one patient having two first-degree re latives. Of these, 17 pairs and one triplet were personally examined. Results: 1) There was a tendency for TD in the affected relatives to be ass ociated with the TD status of the index-patient; this finding was unrelated to age and doses of neuroleptic medication. 2) No association between a fa mily history of schizophrenia or schizoaffective disorder and TD was found. Conclusion: A family history of TD might represent a risk factor for TD, wh ereas a family history of schizophrenia does not.