Sleep Study for Healthy and Neurodevelopmental Children

* INCLUSION CRITERIA : Inclusion criteria for Group A (No known risk) -Consent: Parent/caregiver (legal guardian) can give consent. NIH employees children are eligible to participate with the exception of NIMH employees children. Comments: Parents will provide consent for all minors. Verbal assent will be obtained from minors 7 years and older when applicable. * The child is between 6 months \& 76 months at the time of enrollment for the main study. Comments: Prescreening assessment -Apnea hypopnea index (AHI) \< 2/hour and no other evidence of sleep disordered breathing (SDB) Inclusion criteria for Group B (Known risk) -Consent: Parent/caregiver (legal guardian) can give consent. NIH employees children are eligible to participate with the exception of NIMH employees children. Comments: Parents will provide consent for all minors. Verbal assent will be obtained from minors 7 years and older when applicable. -The child is between 6 months \& 76 months at the time of enrollment for the main study. Comments: Screening assessment -The child meets any one or more of the following: 1. Enrolled in early intervention 2. Getting any targeted therapies 3. Neurodevelopmental or neuropsychiatric disorder 4. Failed ITC (ages 6 months - 24 months) 5. Failed the EI screener (\>24 months) 6. Child s first degree relative has been diagnosed with a neurodevelopmental disorder, such as autism or schizophrenia, or severe mental illness, such as major depressive disorder or bipolar disorder Comments: Screening assessment * Apnea hypopnea index (AHI) \<= 2/hour and no other evidence of sleep disordered breathing (SDB) EXCLUSION CRITERIA: Exclusion criteria for Group A (No known risk) -Meets inclusion criteria for Group B (known risk) Comments: Screening assessment -Any chronic or acute medical condition severe enough to interfere with overnight sleep study acquisition, such as a tracheotomy, uncontrolled seizure disorder, or ventilator dependency, or history of stroke or major neurologic insult. Taking any medications that is known to change sleep parameters within 2 weeks of screening polysomnogram. Comments: Screening assessment: Medical history -Any history of early intervention or diagnosis of a condition that put the child at risk for neurodevelopmental problems (e.g., genetic disorder, prenatal exposures, extreme prematurity) Screening assessment: Medical history Primary language other than English in the home Comments: Screening assessment -Apnea hypopnea index (AHI) \>2/hr or any other evidence of sleep disordered breathing (SDB) * The children of NIMH employees and staff may not take part. Comments: Screening assessment Exclusion criteria for Group B (Known risk) -Any chronic or acute medical condition severe enough to interfere with completion overnight sleep study acquisition, such as a tracheotomy, uncontrolled seizure disorder, or ventilator dependency. Comments: Screening assessment: Medical history -Primary language other than English in the home Comments: Screening assessment -Diagnosed with any of the following common genetic disorders associated with intellectual impairment: Fragile X, Down Syndrome, PraderWilli, Rett, Angelman, Phelan -McDermid, Smith-Lemli-Opitz, identified with a disorders of autonomic dysfunction that might compromise breathing function (examples include congenital central hypoventilation syndrome, familial dysautonmia), disorders of skeletal deformities (Marfan, achondroplasia), a neurogenic condition (spinal muscular atrophy, Duchenne muscular dystrophy, myotonic dystrophy), congenital myopathies or storage diseases (mucopolysaccharidosis, NCL, Wilsons, etc.) -The children of NIMH employees and staff may not take part. Comments: Screening assessment -Apnea hypopnea index \> 2/hr or any other evidence of sleep disordered breathing (SDB)