Open trial of risperidone in 24 young children with pervasive developmental disorders

Objective: To describe tolerability and efficacy of risperidone in very you ng children with pervasive developmental disorders, Method: Twenty-four chi ldren aged 3.6 to 6.6 years (mean 4.6 years +/- 8 months) enrolled during 1 999 and 2000 participated in a 16-week open-label trial with risperidone mo notherapy. Outcome measures included the Children's Psychiatric Rating Scal e (CPRS), Childhood Autism Rating Scale (CARS), Clinical Global Impression- Improvement (CGI-I), and Children's Global Assessment Scale (C-GAS). Result s: Two subjects did not complete the trial because of side effects. The opt imal dose was 0.5 mg/day. After the treatment a 21 % improvement in CPRS an d a 14% improvement in CARS total scores was found. Items related to behavi oral control (hyperactivity, fidgetiness, rhythmic motions) and affect regu lation (lability of affect, angry affect) improved more than 25%. Based on improvement of at least 25% on the CPRS and a score of 1 or 2 on the CGI-I, eight subjects were considered responders. Functional impairment (C-GAS) i mproved more than 25%. Thirteen subjects (54%) were free of any side effect s; in the other participants risperidone was well tolerated, Only three sub jects had a weight gain greater than 10%. Conclusions: Low-dose risperidone may positively affect symptoms in young autistic children, improving disru ptive/hyperactive behavior and affective dysregulation. Further controlled studies in this age group are warranted.