A Longitudinal Natural History Study of Immune Biomarkers in Neuropsychiatric Illness

Background: Some brain or mental health conditions may be caused when a person s immune system attacks their own body. These are called immunologic neuropsychiatric disorders. In this natural history study, researchers want to see if they can find substances in the blood that can help them identify people with this kind of brain or mental illness. What they learn may help them find better ways to diagnose and treat these conditions in the future. Objective: To collect blood samples from people with a brain or mental illness that may be related to their immune system. Eligibility: People ages 1 month or older with a brain or mental illness that may be related to their immune system. Design: Participants will have 1 visit. This visit may be in person or by telehealth. They will answer a questionnaire about their health. They may have blood drawn for testing; this blood sample may also be taken at another medical facility and sent to the researchers. Researchers will look at the participant s medical records and images over time. Researchers will also collect leftover blood or other tissue samples that are taken in the course of a participant s routine health care. Participants may opt to have more visits. These visits will be every 3 to 12 months for up to 5 years. They will be asked about changes in their health since their last visit. They may opt to have blood drawn for research.

* INCLUSION CRITERIA: At the time of enrollment: * Participants must be 1 month or above in age. * Participant biospecimens must be physically located in the United States, or its territories or freely associated states * Participants must have a neuropsychiatric illness of possible neuroinflammatory, or post-infectious etiology based on clinical report and findings from the referring facility/provider. To include one or more of the following: * known or suspected infection or inflammation of the nervous system, * new-onset post-infectious neuropsychiatric symptoms, * new or recurrent neuropsychiatric symptoms in the setting of a diagnosed autoimmune disease or proinflammatory disease state (e.g. systemic lupus erythematosus, sarcoidosis, Sjogren s, Down Syndrome), * new-onset neuropsychiatric symptoms within 5 years of a cancer diagnosis, * new-onset neuropsychiatric symptoms in the context of immune checkpoint inhibitor therapy, * new-onset neuropsychiatric symptoms in the setting of a known or clinically supported primary immune deficiency, * subacute onset psychiatric symptoms with cognitive impairment or personality change defined as a progression from baseline to functionally impaired within 3 months of the onset of symptoms, * or have a typical psychiatric presentation with neuroimaging, CSF, or laboratory findings suggestive of neuroinflammatory process At the time of enrollment participants or surrogates will: * be willing to participate in the protocol s procedures, unless clinically contraindicated, * provide informed consent, either directly or via an appointed legally authorized representative, * be willing to consent to secondary use of clinical data and biological samples collected at and prior to the time of their enrollment EXCLUSION CRITERIA: Participant currently under involuntary commitment/hold.