N,N-
dimethylglycine, a dietary supplement, has been reported to be beneficial in children with
autism and pervasive developmental disorder. We examined the effectiveness of
dimethylglycine in children with
autism and pervasive developmental disorder in a double-blind, placebo-controlled study. Thirty-seven children between 3 and 11 years of age with a diagnosis of
autism and/or pervasive developmental disorder were gender and age matched and randomly assigned to receive either placebo or
dimethylglycine for 4 weeks. All children were assessed before and
after treatment on two behavioral measures, the Vineland Maladaptive Behavior Domain and the Aberrant Behavior Checklist. Standardized neurologic examinations before and
after treatment on 33 children showed no change. An overall improvement on all behavioral measures was observed for both the placebo and the
dimethylglycine groups. However, the improvement among the children who received
dimethylglycine was not statistically different from the improvement observed among the children who received the placebo. The children who participated in this study were a heterogeneous group, and their apparent responses to the
dimethylglycine varied. Some children appeared to respond positively to the
dimethylglycine, and there was a smaller proportion of negative changes in the
dimethylglycine group, but the quantitative changes in the
dimethylglycine behavioral assessments were not significantly different from what was observed among children who received placebo.