Spontaneous involuntary disorders of movement: their prevalence, severity, and distribution in chronic schizophrenics with and without treatment with neuroleptics.

Using two standardized recording techniques (the Abnormal Involuntary Movement Scale [AIMS] and the Rockland Scale), spontaneous involuntary movement disorder was assessed in a sample of 411 hospitalized patients with chronic schizophrenia, 47 of whom apparently had never been exposed to neuroleptic medication. Prevalence of abnormality clearly depended on the criteria of severity adopted, but overall it was high, with half of the sample on the AIMS and two thirds on the Rockland Scale rating 3 (moderate) or more on one item or more. Comparison of those with a history of treatment with neuroleptics and those with no such history showed few significant differences with regard to prevalence, severity, and distribution of abnormal involuntary movements. We concluded that spontaneous involuntary disorders of movement can be a feature of severe, chronic schizophrenia unmodified by neuroleptic drugs.