Since this is a preliminary study prior to a larger controlled trial, the percent of responders receiving one of the drugs will be compared to the percent of responders in the placebo arm. The children will be randomized to achieve 24 total children in each drug arm and 12 in the placebo arm. This 2:2:1 randomization scheme was selected because the expectation is that the percent of responders, in each of the drug arms, will be greater than the percent in the placebo arm. The expectation is that 60% of the children receiving risperidone will respond (Frazier, Meyer et al. 1999), as compared to only 8% in the placebo group (Geller, Cooper et al. 1998). Power was calculated for a one-sided test since if placebo does better no application will be made to NIH. Using nQuery®, version 5.0, a chi-square test, with a 0.05 significance level, will have 96% power to detect the difference. For valproate, the percent of responders is expected to be 55%(Kowatch, Suppes et al. 2000), as compared to the 8% in the placebo arm. Again, using a chi-square test with a .05 significance level, the power will be 86 with 24 in the valproate arm and 12 in the placebo arm. This pilot study does not power to determine if the two drug arms are equivalent.