Non-invasive Vagal Nerve Stimulation as Novel Treatment to Improve Functional Outcomes in Veterans With Alcohol Use Disorder

Inclusion Criteria: 1. Veterans between 21 and 65 years, any race or ethnicity. 2. Meet current DSM-5 diagnosis of moderate or severe AUD (Structured Clinical Interview for DMS-5 (SCID) interview) with at least one functional disability due to alcohol use, current alcohol craving, and current heavy drinking (\>= 5 drinks (men) / \>= 4 drinks (women) on the same occasion, on 5 or more days in the past month) as defined by the Substance Abuse and Mental Health Services Administration (SAMHSA), and mild to moderate withdrawal symptoms during abstinence. 3. Able to forgo consumption of alcohol for 12-24 hours without any serious discomfort or complications. 4. Capable of complying with study schedule, procedures, and speaks English. 5. Able to provide voluntary written informed consent prior to initiation of visit 1. 6. Able and willing to self-administer nVNS/sham stimulation as instructed for the duration of the study, and willing to commit to the return visit at the end of the study. Exclusion Criteria: 1. Clinical Institute Withdrawal Assessment of Alcohol Scale (CIWA-Ar) score \>10 on the day of the scan (symptoms judged to be due to co-existing anxiety or headache disorders will not be counted toward the total). 2. Recent history past 6 months) of severe complications due to alcohol withdrawal (alcohol withdrawal seizures, hallucinations/illusions, delirium tremens). 3. Currently or recently (within last 90 days) enrolled in abstinence-based treatment program. 4. Evidence of a maladaptive pattern of substance use or abuse other than alcohol one month prior to screening visit. 5. Uncontrolled severe psychiatric disorder with psychotic symptoms or cognitive impairment. We will not exclude for PTSD. 6. At risk for suicide requiring urgent higher-level care or homicide (based on the Columbia-Suicide Severity Rating Scale and follow-up clinical interview). 7. History of neurological disorder that might be associated with cognitive dysfunction. 8. History of head trauma involving loss of consciousness \>24 hours 9. Clinically significant uncontrolled/unstable medical illness or clinically significant surgery within 1 month of the screening visit. 10. MRI-related exclusion criteria: cardiac pacemaker, metal fragments in eyes/skin/body, aortic/aneurysm clips, heart-valve replacement, copper intrauterine device, shunt (ventricular or spinal), neuro/bio-stimulators, (for females) pregnant or nursing. Any implants will be reviewed for safety. 11. Vagus nerve stimulation related criteria: active implantable medical device, metallic device implanted at or near the neck, carotid atherosclerosis (narrowing of arteries), cervical vagotomy, clinically significant hypertension, hypotension, bradycardia, or tachycardia, cardiac disease and atherosclerotic cardiovascular disease (severe carotid artery disease (e.g., history of transient ischemic attack (TIA) or stroke), congestive heart failure, severe coronary artery disease or recent myocardial infarction (within 5 years)). 12. Pharmacotherapy for AUD: \>= 2 weeks stability is required to ensure a steady state of medication effects prior to nVNS administration. 13. Currently taking opioids or benzodiazepines. 14. In case it is determined by the investigator during the course of the study, that a subject needs a higher level or care, study participation will be discontinued, and the subject will be excluded from the study.