Magnetic Resonance Imaging (MRI) unlike X-rays and CT-scans does not use radiation to create a picture. MRI use as the name implies, magnetism to create pictures with excellent anatomical resolution. Functional MRIs are diagnostic tests that allow doctors to not only view anatomy, but physiology and function. It is for these reasons that MRIs are excellent methods for studying the brain.

In this study, researchers will use MRI to assess brain anatomy and function in X and Y chromosome variation, healthy volunteers, and patients with a variety of childhood onset psychiatric disorders. The disorders include attention deficit disorder, autism, congenital adrenal hyperplasia, childhood-onset schizophrenia, dyslexia, obsessive compulsive disorder, Sydenham's chorea, and Tourette's syndrome.

Results of the MRIs showing the anatomy of the brain and brain function will be compared across age, sex (gender), and diagnostic groups. Correlations between brain and behavioral measures will be examined for normal and clinical populations.