Neuroleptic-related dyskinesias in autistic children: a prospective, longitudinal study

To report results from a long-term prospective study of safety of haloperidol treatment and prevalence of haloperidol-related dyskinesias.

Subjects were children with autism requiring pharmacotherapy for target symptoms. After baseline assessments, children received haloperidol treatment; responders requiring further treatment were considered for enrollment into the present study. Six-month haloperidol treatment periods were followed by a 4-week placebo period. The procedure was repeated if further haloperidol treatment was required. At specified times children were evaluated by using multiple instruments.

Between 1979 and 1994, 118 children aged 2.3 to 8.2 years participated in the study. The mean dose of haloperidol was 1.75 mg/day. Mainly withdrawal dyskinesias (WD) developed in 40 (33.9%) children; 20 had more than one dyskinetic episode. A subgroup that remained significantly longer in the study and had a significantly higher cumulative dose of haloperidol evidenced a significantly higher incidence of WD. Occurrence rates of tardive dyskinesia (TD) and multiple episodes of TD/WD were higher among girls.

Female gender and pre- and perinatal complications may be involved in susceptibility to dyskinesias; greater cumulative haloperidol dose and/or longer exposure to haloperidol may increase the risk.