This report focuses on the 7.5 million children in the United States with diagnosable mental illnesses, examining developmental, behavioral and emotional disorders in this group. Progress being made toward understanding, preventing, and treating these disorders is documented, future directions for research are put forth, and critical resource requirements for advancing the field are delineated. Chapters include an overview, "Dimensions of Disorder,""Causes and Determinants,""Interventions for Childhood Mental Disorders,""Research Personnel and Infrastructure." Conclusions and recommendations are presented in terms of current knowledge/research progress and research needs/opportunities for the following areas: prevalence and costs; causes and determinants; and interventions. A national plan for National Institute for Mental Health-sponsored child and adolescent mental disorders research is proposed which would: (1) provide support and incentives for an expanded pool of research scientists; (2) provide increased support for individual project, program project, and center grants; (3) provide increased funding for research in such areas as epidemiology, diagnosis, treatment, prevention, neurosciences; and (4) provide for the establishment of an institute-wide consortium concerned with child and adolescent mental health research. (PB)