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

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 and to the VA Healthcare System. 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 different treatment targets. Long-term excessive drinking results in homeostatic dysregulation due to changes in the central and autonomic nervous system, which manifests in psychological and physical distress during abstinence and results in the urge to drink to relieve these symptoms. These symptoms, which can be equated to withdrawal, lead to continued harmful drinking and relapse, and are associated with significant functional impairment and reduced quality of life. Current AUD treatments do not effectively mitigate this homeostatic dysregulation and have risks and side effects as well as other limitations. The investigators propose the vagus nerve, which is the main nerve of the parasympathetic branch of the autonomic nervous system and plays an important role in maintaining and restoring physiological homeostasis, as a novel treatment target for AUD. Noninvasive stimulation of the vagus nerve (nVNS) has been shown to alleviate anxiety, depression, and pain. The investigators hypothesize that nVNS can restore homeostasis and reduce withdrawal-related distress and craving, and consequently improve functional outcomes and quality of life in Veterans with AUD. The goal of this study is to assess treatment efficacy and mechanism of action. The proposed study will include 80 Veterans with current AUD, who will be randomized to receive nVNS or sham stimulation prior to performing a well-validated heat pain task designed to assess neural and physiological correlates of distress. 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 psychological and physiological distress, craving, and functional outcomes will be administered at baseline and post-treatment, as well as at a 1-month follow-up visit.