 Participants are randomly assigned to either a Multi-Setting Early Intervention group or to a Community Intervention group. The Early Intervention group receives parent training and assessment-based behavioral and academic intervention for 1 year, followed by either a high or a low intensity maintenance intervention for an additional 18 months. The Community Intervention group members receive psychotropic medication, special education services, and monthly sessions to obtain information about child development and medical functioning for 2 years. Participants are assessed on six occasions over 4 years. Parents and teachers assess childrens behavior, academic performance, and archival data, including medical and school records. 