Non-invasive Vagal Nerve Stimulation in Alcohol Use Disorder

AUD is a serious mental health disorder that affects more than 40% of US military Veterans, presenting a major burden to this population. Relapse rates of AUD are extremely high; over half of Veterans who complete treatment, relapse within 6 months, highlighting the need for improved treatments or differing treatment targets. Chronic, heavy drinking leads to an imbalance in homeostasis resulting in psychological and physical distress during periods of abstinence, and the urge to drink to relieve these symptoms to restore homeostasis.

nVNS is a low-risk form of neuromodulation that has been shown to alleviate anxiety and chronic pain, and to reduce drug and alcohol relapse in animal models. The investigators hypothesize that nVNS attenuates distress-related craving in AUD in humans by modifying the autonomic nervous system and changing the perception of inner bodily sensations of physiological and affective distress. The investigators also hypothesize that nVNS improves functional outcomes and quality of life in Veterans with AUD.

The proposed research will include 16 Veterans who meet for a diagnosis of AUD. Subjects will be randomly assigned to receive nVNS or sham stimulation prior to performing a well-validated functional Magnetic Resonance Imaging task designed to assess neural correlates of physical distress (via a heat stimulus). Subjects will then self-administer nVNS/sham at home twice a day for 7 days and return for a follow-up visit, during which all study components will be repeated. Behavioral assessments of functional disability, quality of life, psychological and physiological distress, and craving will be administered at baseline, after stimulation, and at follow-up.

The aim of the proposed study is to establish feasibility and acceptability of applying nVNS as a rehabilitative treatment for AUD. In addition, the study will evaluate the preliminary effectiveness of nVNS in improving functional outcomes and quality of life, in reducing distress and craving, and in altering neural activation patterns in brain regions involved in the perception and awareness of distress and pain. The proposed work has the potential to lead to innovative, low-risk treatment options with high promise to significantly improve the care and lives of Veterans as there is a need for alternative treatments for AUD. As such, this novel AUD treatment could be particularly beneficial for Veterans who do not tolerate pharmacotherapy, and who have access or cognitive limitations or stigma concerns that act as barriers to psychotherapy.

Inclusion criteria

• Veteran
• Male subjects between 21 and 65 years of age
• Current DSM-5 diagnosis of AUD with at least one functional disability due to alcohol use, current alcohol craving, and current heavy drinking (>4 drinks on any day or >14 drinks per week)
• Able to forgo consumption of alcohol for 24 hours without any serious discomfort including nausea/vomiting, visual/auditory/tactile hallucinations, or non-essential tremor

Exclusion criteria

• Clinical Institute Withdrawal Assessment of Alcohol Scale (CiWA) score >=9 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).
• Currently or recently (within last 90 days) enrolled in abstinence-based treatment program.
• Evidence of a maladaptive pattern of substance use or abuse other than alcohol one month prior to screening visit.
• Severe mental illness, e.g., psychosis or bipolar disorder
• At risk for suicide or homicide
• History of neurological disorder that might be associated with cognitive dysfunction.
• History of head trauma involving loss of consciousness >24 hours
• Clinically significant uncontrolled/unstable medical illness or clinically significant surgery within 1 month of the screening visit.
• 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
• Vagus nerve stimulation related criteria: history of carotid endarterectomy, severe carotid artery disease (e.g., history of transient ischemic attack (TIA) or stroke], congestive heart failure, cardiac arrhythmia, known severe coronary artery disease or recent myocardial infarction (within 5 years), history of seizure or syncope (within past year), prior neck surgery.