This study is a brief (3 month) longitudinal study following children between the ages of 4-16 years old who have been diagnosed with Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS). Parents and children (who are at a 2nd grade reading level) will complete questionnaires online or in person weekly for 3 months. Additionally, parents will track their child's symptoms 3 times/week using a mobile application for 3 months. The investigators are hoping to begin to characterize the longitudinal trajectory of neuropsychiatric symptoms in children with PANS. Additionally, the study will seek to identify baseline demographic and clinical characteristics (e.g., gender, recent onset versus chronic course, GAS versus other triggers) that predict severity of baseline neuropsychiatric symptoms and predict change in symptoms over time.

Inclusion Criteria:

• English-speaking boys and girls ages 4-16 years
• Abrupt onset of OCD or severely restricted food intake
• At least 2 equally abrupt-onset concurrent neuropsychiatric symptoms from the following 7 categories: anxiety, emotional lability/depression, irritability/aggression/severely oppositional behaviors, behavioral/developmental regression, deterioration in school performance, sensory or motor abnormalities (e.g. tics), somatic symptoms (e.g., urinary, sleep)
• Neuropsychiatric symptoms are not better explained by a known neurological or medical disorder.

Exclusion Criteria:

- Too unstable psychiatrically or medically to participate safely in the protocol, per clinical judgment of the Principal Investigator or Co-Investigator

Children with an established or suspected diagnosis of PANS/PANDAS.