Neurodevelopmental origins of tardivelike dyskinesia in schizophrenia patients and their siblings.

The question of whether dyskinesia of the type found in tardive dyskinesia (TD) related to schizophrenia has a neurodevelopmental background was studied in a sample of 60 younger schizophrenia patients (mean age 38 years) and 21 of their non-ill siblings. TD-like dyskinesia was studied in relation to selected risk factors in the patients, and to neurological abnormality and parkinsonism in both patients and siblings. One or more signs of TD-like dyskinesia in patients were predicted by male gender, a history of obstetric complications, shorter illness duration, and shorter neuroleptic exposure. One or more signs of TD-like dyskinesia were found in 28.5 percent of the siblings and tended to be associated with neurological abnormality. Little co-occurrence of TD-like dyskinesia was found in the sibling and the patient in the same family. Patients' TD-like dyskinesia was significantly associated with hard neurological signs (independent of involuntary movements) but not with soft signs or primitive reflexes per se. TD-like dyskinesia showed a significant positive relationship to parkinsonism in patients. TD-like dyskinesia in younger schizophrenia patients appears to have neurodevelopmental antecedents and seems to represent one aspect of the total neurological abnormality associated with schizophrenia.