Spontaneous dyskinesia in first-degree relatives of chronically ill, never-treated people with schizophrenia.

BACKGROUND We have suggested recently that there may be a subgroup of schizophrenia, namely schizophrenia with dyskinesia and striatal pathology. Might movement disorders be more common in relatives of those with schizophrenia and dyskinesia than in relatives of those without dyskinesia? Aims To determine the prevalence of abnormal movements in first-degree relatives of people with schizophrenia who themselves do or do not have abnormal movements. METHOD Chronically ill, never-treated people with schizophrenia in south India (n=70) and their first-degree relatives (n=181) were examined for dyskinesia using the Abnormal Involuntary Movements Scale (AIMS) and for parkinsonism by the Simpson and Angus scale. RESULTS Of all relatives, 25 (14%) had dyskinetic movements in at least one body area and 6 (3%) had parkinsonism. Siblings of people with schizophrenia and dyskinesia, compared with siblings of people without dyskinesia, had a higher total AIMS score and more had mild dyskinetic movements in at least one area (5/15 v. 3/34, P=0.04). There were no between-group differences in parkinsonism. CONCLUSIONS Dyskinesia but not parkinsonism is more common in siblings of people with schizophrenia who have the corresponding movement disorder.