Non-invasive Vagal Nerve Stimulation in Alcohol Use Disorder

Alcohol use disorder (AUD) is a major health concern amongst Veterans as it causes poor health, lost days at work, impaired psychosocial functioning, and decreased quality of life. Current treatment options for AUD show limited effectiveness, which is exemplified by high relapse rates. Chronic heavy drinking results in psychological and physical distress during abstinence, including anxiety, irritability, and general discomfort, which increases the urge to drink to relieve these symptoms. The hypothesis of this study is that noninvasive vagal nerve stimulation (nVNS) can modify the perception of such inner bodily sensations of distress, and consequently reduces the drive to drink for relief. The aim of this study is to establish feasibility and acceptability of applying nVNS as a rehabilitative treatment for AUD in Veterans. The study will also evaluate the effect of nVNS on functional outcomes, quality of life, distress, and craving, and if nVNS alters neural activation patterns in brain regions involved in the perception and awareness of distress and pain.

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.