• INCLUSION CRITERIA FOR HEALTHY CONTROLS:

Subjects consenting to participation in the study

-Over 3 years of age with no upper limit for age at time of enrollment.

EXCLUSION CRITERIA FOR HEALTHY CONTROLS:

• Presence of any psychiatric disorder in the subject, sibling, or other first-degree relative.
• Current or past use of psychiatric medication.
• Special service needs in school.
• Presence or history of medical conditions known to affect cerebral anatomy.
• Dental braces.
• Metal in the body or other contraindications for MRI scanning.
• For females who have reached menarche: Pregnancy or inability or unwillingness to undergo pregnancy testing.

INCLUSION CRITERIA FOR PATIENT POPULATIONS:

• Male and female subjects over 3 years of age with no upper limit for age at time of enrollment.

• Currently meet criteria for at least one of the following:

  • DSM-IV (or other approved) criteria for one of the following clinical diagnoses: Multi-Dimensionally Impaired, Obsessive Compulsive Disorder, Childhood Onset Schizophrenia, Turner Syndrome, Autism Spectrum Disorder, Asperger Syndrome, High Functioning Autism, Pervasive Development Disorder
  • Sex chromosome aneuploidy as determined by karyotype (including XXX, XXXX, XXXXX, XXY, XXYY, XXXY, XXXXY, XYY).
  • ICD-10 criteria for Congenital Adrenal Hyperplasia and Cushings Syndrome.
  • ADHD
  • Down's Syndrome
• Newly enrolled adults and minors once they become adults over age 18 who cannot give consent due to limited capacity may have a surrogate, i.e., a legally responsible representative (LAR), sign the consent. LARs include DPA holders, court-appointed legal guardians, or parents or siblings over 18 years of age. We will consult with the Human Subjects Protection Unit as necessary.

EXCLUSION CRITERIA FOR ALL PATIENT POPULATIONS:

• Dental braces.
• Metal in the body or other contraindications for MRI scanning.
• For females who have reached menarche: Pregnancy or inability or unwillingness to undergo pregnancy testing.
• Evidence of another medical condition or traumatic event known to affect cerebral anatomy.
• A known genetic disorder (other than the condition under investigation) that would be expected to significantly impact findings from cognitive testing and/or neuroimaging.

ADDITIONAL INCLUSION CRITERIA FOR ADHD PARTICIPANTS:

• Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)-defined ADHD. The DSM-IV diagnosis of ADHD will be based on the Parent Diagnostic Interview for Children and Adolescents.
• Conners' Teacher Hyperactivity rating greater than 2 SD above age- and sex-specific means.

ADDITIONAL EXCLUSION CRITERIA FOR ADHD PARTICIPANTS:

• A full-scale IQ of less than 80.
• Birth before 34 weeks of gestation.
• Other axis I psychiatric disorder requiring treatment with medication at study entry (with the exception of oppositional-defiant disorder).

ADDITIONAL INCLUSION CRITERIA FOR DOWN SYNDROME PARTICIPANTS:

• Confirmed chromosomal diagnosis of Trisomy 21.
• Age between 3 years and 17 years, 11 months. This upper age limit was chosen for two reasons. First, the vast majority of studies of the neuroanatomy of Down syndrome have focused on adult populations and the heightened risk for Alzheimer's disease in this group. Thus, additional pediatric studies are needed to understand the early developmental course of the neuroanatomical and neuropsychological phenotype associated with Down syndrome. Second, by excluding participants over the age of majority, issues related to capacity to provide legal consent to participate will be avoided. With these and all pediatric participants, care will be taken to assure that assent is obtained and periodic checks will be completed throughout testing to determine continued willingness to complete all tests and procedures.

ADDITIONAL INCLUSION CRITERIA FOR PARTICIPANTS WITH AUTISM SPECTRUM DISORDERS:

• Meeting DSM-IV criteria for one of the pervasive developmental disorders (i.e., autistic disorder, Asperger disorder, or pervasive developmental disorder-not otherwise specified).
• Having a minimum IQ of 70.