Familial occurrence of tardive dyskinesia

Tardive dyskinesia (TD) is a severe side effect of neuroleptic medication. Among other risk factors, genetic predisposition is thought to confer suscebtibility to TD. However, there is a substantial lack of studies addressing the question if TD runs in families. Besides sporadic reports, there have only been two studies to assess concordane for TD in first degree relatives [Yassa and Ananth, 1981; Youssef et al., 1989]. These samples comprised 11 and 8 patients-relative-pairs, respectively. Either study found concordance for the presence or absence of TD in all tested patient-relative pairs. We examined 288 patients receiving long-term neuroleptic medication for psychiatric diagnosis using SADS-LA interview and the presence or absence of TD according to RDC criteria. Patients with transient or developed TD and those with a DSM-IV diagnosis other than schizophrenia or schizoaffective disorder were excluded. Family history for psychosis was assessed by family history method. Thirty-two patients had first degree relatives with schizophrenia or schizoaffective disorders. We were able to examine 16 relative-pairs for the presence or absence of TD and psychiatric diagnosis using SADS-LA interview. Thirteen pairs showed concordance. This result confirms the findings of the previous reports. Interestingly, the majority of patients-relative-pairs is concordant for the absence of TD (11/13). In this sample of patient-relative-pairs only 22% display TD, whereas in the overall sample 43% display TD. This observation is in line with previous reports [Bartels et al., 1985; Wegner et al., 1985] which found TD to be more likely in patients without a familial component of schizophrenia.