Participation in this study will last 11 to 12 weeks, followed by a 5- to 7-month follow-up period. On the basis of parent and teacher evaluations of each child's behavior, invitations to participate in screening procedures for the study will be extended to children and their parents. There will be two screening visits, during which the child will undergo reviews of medical and developmental history, diagnostic interviews, intelligence testing, academic achievement testing, and neuropsychological testing. The child and parent will be videotaped in a series of interactions, and both will complete questionnaires about child functioning, parent functioning, family functioning, and family relations. The child's teacher and school principal will also be contacted to ensure that they are willing to participate in the study.