Abnormal Involuntary Movements in Neuroleptic-Naive Children and Adolescents

Abstract

Objective: To determine the prevalence of and identify risk factors for abnormal involuntary movements in a well-characterized community sample of neuroleptic-naive children and adolescents. Method: The Abnormal Involuntary Movement Scale (AIMS) was administered to 390 subjects aged 3–17 years who were in foster care. Additional instruments were used to assess intellect and behaviour problems. Results: A total 12.6% of subjects had at least 1 rating of “mild” movements on AIMS; these included 4.1% with at least 2 ratings of “mild” or 2 of “moderate” severity. Significant risk factors for movement disorder were younger age, lower IQ, and more severe behaviour problems. The abnormal movements were usually orofacial, and the affected subjects were generally unaware of these movements. Conclusion: The base prevalence of abnormal involuntary movements must be considered in children and adolescents assessed for medication in order to determine the true rate of motor side effects.