Cerebral MRI will be used to assess brain anatomy and function in normal volunteers and subjects with a variety of childhood onset psychiatric disorders including attention deficit disorder, autism, congenital adrenal U hyperplasia. childhood-onset schizophrenia. dyslexia, multidimensional impairment syndrome. obsessive compulsive disorder, Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infection (PANDAS), stuttering, Sydenham's chorea, and Tourette's Syndrome. Quantitative measures of brain structure and function will be compared across age, gender. and diagnostic groups. Correlations between brain and behavioral measures will be examined for normal and clinical populations.