EEG Biomarkers for OUD: Diagnostic, Prognostic, and Predictive Applications

Inclusion Criteria: * For OUD Subjects: 1. Providing informed consent to participate in the study. 2. 22 to 85 years old. Having a diagnosis of OUD • OUD of more than 6 months duration as defined by Diagnostic and Statistical Manual of Mental Disorders (DSM-5) \[71\] with a positive urine toxicology screen who still feel craving. 4\. Lives in immediate area with no plans to relocate. For age-matched controls: 1. Providing informed consent to participate in the study. 2. 22 to 85 years old. 3. Lives in immediate area with no plans to relocate Exclusion Criteria: * For OUD Subjects: 1. Recently started on antiepileptic drug therapy. 2. Ingestion of poppy seeds or herbal teas containing Papaveris fructus (may cause a positive opiate test for morphine, codeine \[72,73\]). 3. History of neurological disorders involving stroke, brain tumors, or epilepsy as self- reported. 4. History of unexplained fainting spells as self-reported. 5. History of head injury resulting in more than a momentary loss of consciousness as self-reported. 6. History of brain surgery as self-reported. 7. Suffering from severe depression. 8. Active malignancy. For age-matched controls: 1. Recently started on antiepileptic drug therapy. 2. History of neurological disorders involving stroke, brain tumors, or epilepsy as self- reported. 3. History of unexplained fainting spells as self-reported. 4. History of head injury resulting in more than a momentary loss of consciousness as self-reported. 5. History of brain surgery as self-reported. 6. Suffering from severe depression. 7. Active malignancy.