What Is Vagus Nerve Stimulation? How Does It Relate to Alcohol Use Disorder?

After a long, stressful day at work, maybe you’d find yourself at home reaching for a glass of wine. Then, what started as a single drink to unwind turned into a nightly ritual of more than one. The once-casual habit is now a necessity, a crutch to lean on to relax. Sound familiar? This scenario is all too common, and many of us find ourselves trapped in a cycle of drinking that’s difficult to break. But what if there were a way to break this cycle with support using the latest advancements in neuroscience?

Enter vagus nerve stimulation, a treatment option that’s been making waves not just for its use in epilepsy and depression, but also for its potential in treating alcohol use disorder (AUD). Let’s delve into the science of vagus nerve stimulation and examine whether and how it works to support us on a journey towards a future with less or no alcohol.

Getting To Know the Vagus Nerve

The vagus nerve, commonly referred to as one nerve, is actually a system of nerves that controls our parasympathetic nervous system. It serves as a kind ofsuperhighway that carries information within our brain and from our brain to the rest of our body. Its purpose is calming the body and promoting “rest and digest” activities.

This system of nerves delivers information to help us carry out involuntary functions such as digestion, heartbeat, and respiration. It’s also involved in reflex actions such as coughing, sneezing, swallowing, and vomiting. The vagus nerve connects the brain to other systems, which affect such functions as muscle sensations, taste, speech, and our immune response. Last but not least, the vagus nerve plays a key role in promoting and protecting brain function. 

As we can see, the vagus nerve impacts our entire body and is essential to almost all body functions. Let’s understand why we would want to stimulate it and what conditions it might benefit.

What Is Vagus Nerve Stimulation? 

Vagus nerve stimulation (VNS) is a technique that sends electrical pulses to the vagus nerve to stimulate it, thereby impacting physiological functions. There are two methods for conducting VNS: via an implant similar to a pacemaker or noninvasively with the electrical pulses delivered through the skin, known as transcutaneous vagus nerve stimulation.

VNS is designed to change how our brain cells work by stimulating nerves in certain areas of the brain, known as neuromodulation. Currently, VNS is FDA-approved to treat epilepsy, depression, and aid in stroke rehabilitation. However, it’s also being studied for other uses, including treatment for migraines, obesity, bipolar disorder, Alzheimer's and Parkinson’s diseases. Recently, VNS has been studied as a potential treatment for AUD. To understand why, let’s understand how the vagus nerve and alcohol affect one another.

The Interaction Between the Vagus Nerve and Alcohol

Alcohol negatively impacts the vagus nerve in several ways. When we drink, alcohol enters our bloodstream and targets our central nervous system, causing symptoms of intoxication. As our liver works to get rid of the alcohol, it starts by breaking it down into acetaldehyde, a compound that’s toxic to our body. The toxins damage our vagus nerve, leading to many different health issues.

1. Vocal Vexation

After consistent exposure to alcohol, vagus nerve damage, known as “vagal neuropathy,” can occur. This affects vocal motor branches of the vagus nerve, resulting in chronic cough, or vocal discomfort. Ever wake up the day after drinking with a sore throat or hoarse voice? Vagal neuropathy is that feeling, but long term, not just the day after drinking.

2. Cardiac Concerns

Drinking also reduces function of the nerves in our heart (decreased cardiac vagal tone), which makes our heart work harder and signals our brain to send a fight-or-flight response. Reduced cardiac vagal tone is associated with an increased risk of heart failure. 

3. Chronic Inflammation

Alcohol inhibits the anti-inflammatory effects of alpha7 nicotinic acetylcholine receptor, or a7-receptor, which plays a role in inflammation of the vagus nerve. Research shows that alcohol’s impact on our immune activity is one of the reasons the vagus nerve, hangovers, and chronic inflammation are connected. This is because alcohol impairs cytokines, proteins found in our immune system and vagus nerve that control our body’s inflammatory response. 

4. Vagus Nerve Overdrive

Decreased vagus nerve activity has many risks, but so does excessive vagus nerve activity. Especially when fluid levels aren’t optimal (which happens when we drink), increased vagus nerve activity can trigger a number of issues, including loss of consciousness, organ damage, atrial fibrillation (AFib), ringing in the ears, and more. 

5. Other Health Hazards

Since the vagus nerve involves many systems in our body, disruptions can cause other health issues. Alcohol’s impact on the vagus nerve can interfere with sleep patterns, raise blood pressure, and increase risk of heart disease, asthma attacks, arthritis, and obesity. 

Clearly, alcohol is harmful to the vagus nerve in many ways. However, the same is true when the script is flipped. Research shows that damage to the vagus nerve can increase alcohol intake. This is because the vagus nerve regulates the hypothalamic-pituitary-adrenal (HPA) axis, which can affect cues and cravings for alcohol. Vagus nerve disruptions also impact alcohol use disorder. Let’s learn more about what AUD is to understand how it’s connected to the vagus nerve. 

Understanding Alcohol Use Disorder

Alcohol use disorder (AUD) is characterized by the impaired ability to quit or cut back on alcohol despite its negative effects. Diagnosis and severity of AUD is determined using criteria from the DSM-5. AUD ranges from mild to severe, but involves physical and neurological dependence, making it difficult to stop drinking even when we want to. 

The vagus nerve, which involves our brain and multiple systems in our body, controls the neurological and physiological processes that AUD affects. Let’s go into further detail on the science behind the effects of VNS on AUD to understand why it’s being proposed as a potential treatment option. 

Stimulation of the Vagus Nerve: Alcohol Use Disorder Treatment Options

Remember how we discussed that VNS is used to treat various conditions? Well, that’s because the vagus nerve impacts many processes in our body. VNS has physical and mental health benefits that help mitigate symptoms of AUD and alcohol withdrawal. A 2021 study found that VNS improved sleep quality and depression in patients with AUD. Similarly, a current clinical trial is testing how VNS modifies the perception of bodily sensations of distress associated with AUD. The hope is that VNS can reduce the urge to drink for relief and become a noninvasive treatment option for AUD. 

Aside from reducing symptoms of AUD and alcohol withdrawal, VNS is being studied as a potential treatment to reduce alcohol cravings and promote recovery. A study discussing how VNS could improve AUD treatment found that VNS directly stimulates GABA and catecholamines (neurotransmitters and hormones responsible for physical and emotional stress) that are negatively affected by alcohol. This study concludes that VNS can be an effective supporting treatment for AUD. Several animal studies also show promising results for VNS reducing drug cravings and developing positive behaviors. A preclinical study on rats found that VNS helped develop new behaviors that replaced drug-seeking ones. Another study utilized cocaine but found the same results, suggesting that this idea can be translated to other substances such as alcohol. 

Other Treatments for AUD

VNS can be even more beneficial in treating AUD when it is used in conjunction with other methods. Other effective treatment options for AUD include the following: 

• Peer support groups. Research shows that social support is a cornerstone of recovery because it helps fuel change. 
• Medication. Over time, our brain and body can expect a certain level of alcohol. Medication is commonly used with other treatment approaches to help us adapt to not having alcohol and aid in severing neurological and physical dependence.
• Behavioral therapies. Cognitive behavioral therapy and dialectical behavior therapy are frequently used to treat AUD as they help us identify behaviors we want to change and develop skills to build more positive habits.
• Psychological therapy. Talk therapy is helpful in AUD treatment as it helps us identify the root causes of our drinking habits. 
• Holistic healing. This includes mindfulness strategies, herbal supplements, physical activity, art and music therapy, and more. The idea is to bridge physical healing and rehabilitation of the mind to work towards an alcohol-free lifestyle. 

While these options have proven to be effective in treating AUD, the benefits of VNS suggest another path to healing. Let’s get into some tips for stimulating the vagus nerve naturally to support our journey to quitting or cutting back on alcohol. 

Tips for Stimulating the Vagus Nerve

Vagus nerve stimulation puts us in a more relaxed “rest and digest” state. We can get there using a number of different practices. 

• Take deep breaths. When we’re stressed, we tend to breathe more shallowly, which deprives the vagus nerve. Focus on the rhythm of the breath while engaging in slow, deep belly breathing to reduce stress and activate the vagus nerve.
• Meditate. Meditation activates the vagus nerve by lowering our heart rate and blood pressure. Use guided meditations or practice mindfulness strategies such as mental body scans or expressing gratitude. 
• Exercise. Physical activity increases blood flow to the brain, which helps stimulate the vagus nerve. Research shows that endurance activities such as cycling, running, and swimming help control parasympathetic activity in the brain, which reduces stress. Vagus nerve stimulation accounts for the feeling we call “runner’s high.”
• Get a massage. Gentle, moderate pressure to all areas of the body helps stimulate the vagus nerve. Refrain from deep tissue or painful massages, as they can trigger the body’s sympathetic nervous system or “fight-or-flight” response.
• Get into the cold. Short-term exposure to cold temperatures (known as cryotherapy) helps reduce the body’s natural stress response by stimulating the vagus nerve. Finish your shower with a cold-water rinse or dip your face into ice-cold water. 
• Feel inspired. The experience of awe and wonder during activities such as walks in nature, connecting with others, or listening to inspiring music inhibits the body’s stress response. This can reduce pain, reduce inflammation, and improve our sleep quality and mood. 

These practices improve our overall mental and physical well-being, empowering us on the journey to improving our relationship with alcohol. 

Stimulating Change

The vagus nerve is a crucial part of our parasympathetic nervous system that connects our brain and other systems in our body. The positive benefits of VNS on physical and mental health include the management of withdrawal symptoms and reduction of alcohol cravings. This novel approach may not only serve as a new treatment for AUD but also suggests a new avenue to change and heal in other ways.