A 3-Year Naturalistic Study of 53 Preschool Children With Pervasive Developmental Disorders Treated With Risperidone

Background: Only sparse and short-term data are available on pharmacologic treatments in very young children with pervasive developmental disorders (PDD). The purpose of this 3-year naturalistic study (March 1999-April 2002) is to describe the clinical outcome of a consecutive sample of preschool children with PDD treated with risperidone monotherapy.

Method: The sample consisted of 45 boys and 8 girls aged 3.6 to 6.6 years (mean ± SD age = 4.6 ± 0.7 years) with a DSM-IV diagnosis of autistic disorder or PDD, not otherwise specified. Outcome measures included the Children’s Psychiatric Rating Scale (CPRS), Clinical Global Impressions-Improvement scale (CGI-I), Children’s Global Assessment Scale (CGAS), and a checklist for risperidone side effects.

Results: Patients received risperidone for a period ranging from 1 to 32 months (7.9 ± 6.8 months). Twenty-five patients (47.2%) continued to receive risperidone after the study was completed, while 28 (52.8%) discontinued due to side effects (22.6% [N = 12]), parents’ choice (18.9% [N = 10]), lack of efficacy (5.7% [N = 3]), and decision of the treating psychiatrist (5.7% [N = 3]). The optimal dose was 0.55 ± 0.2 mg/day. Significant improvement at the last observation was found in CPRS (p < .0001) and CGAS (p < .0001) scores. On the basis of both an improvement of 25% in CPRS score and a score of 1 or 2 on the CGI-I, 46.8% (N = 22) of subjects were considered responders. Behavioral disorders and affect dysregulation were more sensitive to treatment than was interpersonal functioning. Responders received higher doses of medication for a longer period and had a greater weight gain than did nonresponders. Increased prolactin levels without clinical signs (65% [24 of 37]) and increased appetite (15% [8 of 53]) were the most frequent side effects.

Conclusion: These findings suggest that low-dose risperidone may positively affect the clinical outcome in young children with PDD not only in the short-term, but also in the long-term period.