Brexpiprazole in Alcohol Use Disorder

Inclusion Criteria: * Ages 21-65. * Meet DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th edition) diagnostic criteria for AUD, as assessed by the Structured Clinical Interview for DSM-5 (SCID-5). * Currently not engaged in, and does not want treatment for, AUD. * Currently not taking any medication for AUD. * Able to read and understand questionnaires and informed consent. * Lives within 50 miles of the study site. * Physically healthy with no history of significant medical illness. * Negative urine drug screen (UDS) for all substances of abuse prior to taking the first dose of medication. Please contact clinical site for additional inclusion criteria. Exclusion Criteria: * Refusal of valid written consent. * Insufficient English skills for consenting or interviews. * Severe claustrophobia or morbid obesity that preclude placement in the MRI scanner. * Contraindications to MRI scanning, ferrous metal in the body including intracranial, intraorbital, or intraspinal metal, pacemakers, cochlear implants or other non-MRI-compatible devices. * History of head injury with loss of consciousness for more than 2 minutes, neurological illness, or history of neurosurgical procedures. * Current DSM-5 diagnosis of any other substance use disorder except Nicotine Use Disorder. * Current DSM-5 psychotic, mood, anxiety, obsessive-compulsive, trauma-related, or eating disorder, as assessed by SCID-5. * Current suicidal ideation or homicidal ideation. * Current use of any psychoactive medication, as evidenced by self-report and UDS. * History of severe alcohol withdrawal (e.g., seizure, delirium tremens), as evidenced by self-report and assessment with Clinical Institute Withdrawal Assessment for Alcohol-Revised (CIWA-Ar). * Clinically significant medical problems such as cardiovascular, renal, gastrointestinal, or endocrine problems, as evidenced by medical history and physical exam. * Past alcohol-related medical illness, such as gastrointestinal bleeding, pancreatitis, or peptic ulcer. * Current or past hepatocellular disease, as indicated by verbal report or elevations of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than 3 times the upper limit of the normal range at screening. * Females of childbearing potential who are pregnant (by plasma or urine HCG), nursing, or who are not using a reliable form of contraception. * Current charges pending for a violent crime (not including DUI-related offenses). * Currently incarcerated. * Lack of a stable living situation. * History of head injury with loss of consciousness for more than 2 minutes, neurological illness, or history of neurosurgical procedures. * Decisionally challenged.