This study is an investigation of the neurologic, immunologic, and rheumatologic markers of Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS). PANS is a condition characterized by the abrupt, dramatic onset of obsessive compulsive disorder (OCD) and/or eating restriction accompanied by equally abrupt and severe co-morbid neuropsychiatric symptoms, which include anxiety, emotional lability, depression, irritability, aggression, oppositionality, deterioration in school performance, behavioral (developmental) regression, sensory amplification, movement abnormalities, sleep disturbance, and urinary frequency. PANS is thought to be caused by infection, inflammation, or alternate triggers that is associated with a brain response that leads to these symptoms. The purpose of this study is to examine specific neurologic, immunologic, rheumatologic, and genomic, components in children with the acute-onset of psychiatric symptoms. This research may begin to uncover a much larger story of autoimmune processes that are involved in psychiatric disorders of childhood. By better understanding the etiologic components of psychiatric phenomenon, future treatments may be better targeted to underlying causes.