Abnormal involuntary movements are linked to psychosis-risk in children and adolescents: Results of a population-based study.

BACKGROUND

Altered motor behavior has consistently been reported in medication-naive adult patients with schizophrenia and first episode psychosis and adults at clinical high risk for psychosis (CHR). This study is the first to evaluate the prevalence of abnormal involuntary movements in a community sample of children and adolescents with and without CHR.

METHODS

We examined CHR in 102 children and adolescents aged 8-17years from the general population of the Canton Bern. Attenuated and brief intermittent psychotic symptoms, as well as basic symptoms, were assessed using the Structured Interview for Psychosis Risk Syndromes and the Schizophrenia Proneness Instrument, Child & Youth Version. Motor symptoms were assessed using the Abnormal Involuntary Movement Scale (AIMS). Additionally, psychosocial functioning, a neurocognitive test battery, and DSM-IV Axis I disorders were examined.

RESULTS

Eleven (10.8%) participants met CHR criteria, 13 (12.7%, 5 with and 8 without CHR) met criteria for increased abnormal involuntary movements (AIMS≥2). Both AIMS total scores and the percentage of children with AIMS≥2 were significantly higher in the CHR group. Psychosocial functioning was reduced in subjects with abnormal involuntary movements, and movement abnormalities were linked to deficits in attention and perception but not to the presence of non-psychotic mental disorders.

CONCLUSIONS

Our findings suggest that abnormal involuntary movements are linked to psychosis risk in children and adolescents from the general population. Thus, abnormal involuntary movements might represent an additional useful and easily accessible predictor of psychosis.