Driven by the hypotheses that many of the most severe neuropsychiatric disorders of childhood onset are associated with deviations from the path of normal brain development, the neuroanatomical substrates of which can be detected by magnetic resonance imaging, we are acquiring brain images in healthy and neuropsychiatrically impaired subjects. To explore gene, brain, behavior relationships in health and illness we are also acquiring DNA along with clinical, behavioral, and cognitive data in singleton and twin populations. Controls and clinical populations are screened and characterized in behavioral, cognitive, and physical domains. Longitudinal brain MRI scans are acquired and analyzed using state-of-the-art image analysis techniques. Data from the project has resulted in seminal papers on Attention-Deficit/Hyperactivity Disorder, Childhood-Onset Schizophrenia, and normal pediatric brain development. The data from the normative project is unique in its longitudinal nature and sample size.