The Role of Dysmyelination in Cognitive Impairment of Psychotic Spectrum Disorders

Inclusion Criteria: Patients: * current DSM-5-defined diagnosis of a schizophrenia or bipolar disorder. A best estimate diagnostic approach will be utilized in which information from the Diagnostic Interview for Genetic Studies (DIGS) is supplemented by information from family informants, psychiatrists, and medical records to generate a diagnosis as needed * no alcohol or substance abuse during the last 6 month * no current substance-induced psychotic disorder or a psychotic disorder due to a general medical condition determined by DSM-5 criteria * ages 18 to 30 years old; * any race * competent and willing to sign informed consent * within 5 years from the disease onset. Siblings: * have the same biological parents as their PSD sibling * any race * no current or past history of psychotropic medication usage * no alcohol or substance abuse during the last 6 months * competent and willing to sign informed consent; * ages 18 to 30 years old. Healthy controls: * matched for age to PSD patients * no current or past history of psychotropic medication usage * no prodromal symptoms and no family history of PSD * no alcohol or substance abuse during the last 6 months * competent and willing to sign informed consent. * all attempts will be made to recruit controls with similar parental SES as patients. However, given that PSD are both a neurodevelopmental and familial disorder, exact matching for educational level or IQ may neither be possible nor desirable. have the same biological parents as their PSD sibling * any race * no current or past history of psychotropic medication usage * no alcohol or substance abuse during the last 6 months * competent and willing to sign informed consent; * ages 18 to 30 years old. Exclusion Criteria: * a serious neurological or endocrine disorder or any medical condition or treatment known to affect the brain, 2) organic brain disorder, mental retardation, or significant medical illness; * significant risk of suicidal or homicidal behavior; * must not have met DSM-5 criteria for current alcohol or drug dependence in the last 6 months; * contraindications to MRI scanning (i.e., metal implants, pacemakers, pregnancy, etc.); * documented loss of consciousness (LOC) for longer than 30 minutes or LOC with any neurological sequelae.