Auricular transcutaneous vagus nerve stimulation for alcohol use disorder: A chance to improve treatment?

Abstract

Alcohol use disorder (AUD) is a relapsing–remitting condition characterized by excessive and/or continued alcohol consumption despite harmful consequences. New adjuvant tools, such as noninvasive brain stimulation techniques, might be helpful additions to conventional treatment approaches or even provide an alternative option for patients who fail to respond adequately to other treatment options. Here, we discuss the potential use of auricular transcutaneous vagus nerve stimulation (atVNS) as an ADD‐ON intervention in AUD. Compared with other techniques, atVNS has the advantage of directly stimulating nuclei that synthesize GABA and catecholamines, both of which are functionally altered by alcohol intake in AUD patients. Pharmacological options targeting those neurotransmitters are widely available, but have relatively limited beneficial effects on cognition, even though restoring normal cognitive functioning, especially cognitive control, is key to maintaining abstinence. Against this background, atVNS could be a particularly useful add‐on because there is substantial meta‐analytic evidence based on studies in healthy individuals that atVNS can enhance cognitive control processes that are crucial to regaining control over drug intake. We discuss essential future research on using atVNS as an ADD‐ON intervention in AUD to enhance clinical and cognitive outcomes by providing a translational application. Given that this novel technique can be worn like an earpiece and can be employed without medical supervision/outside the clinical settings, atVNS could be well integratable into the daily life of the patients, where the task of regaining control over drug intake is most challenging.

Interoception Within the Context of Impulsivity and Addiction

“…Studies in humans have shown that tVNS can significantly reduce withdrawal symptoms, pain, and distress levels, and decrease the risk of relapse in individuals with opioid addiction [ 77 ]. Furthermore, tVNS has been linked to improved cognitive control processes, which are important for regaining control over drug use (reviewed in [ 78 ]). Given its ability to reduce the behavioural and physiological effects of withdrawal and improve cognitive control, tVNS has great potential as a readily available and easily implementable adjunctive treatment for addiction, as it can be used like an earpiece and requires minimal medical supervision outside of clinical settings.…”

Regaining control over opioid use? The potential application of auricular transcutaneous vagus nerve stimulation to improve opioid treatment in China

“…Concerning feasibility, atVNS is a non-invasive electroceutical that can be useful as an ecological momentary intervention (EMI): it is a pocket-sized, light and handy device that can be easily operated by the users without any medical supervision, as long as they have undergone thorough training under a physician's supervision. 12,110 It should be noted that the NEMOS ® atVNS device has predetermined parameters, such as stimulation frequency, pulse width, on-off cycle, which users cannot adjust. Additionally, current intensity cannot be set higher than 5 mA and the device has a built-in safety feature that automatically stops functioning once the maximum daily stimulation time of 4 h has been reached, preventing overstimulation or misuse.…”

“…Several neuroimaging studies have demonstrated that atVNS activates, among other areas, the LC, 40,41,44–47 which is considered to be the key structure involved in opioid withdrawal 17,18 . Even though different neurotransmitter systems have been shown to be modulated by atVNS, 12 the primary neuromodulator synthesized by the LC is the catecholamine NA 48 . As suggested by Konjusha et al, 12 findings that atVNS modulates the LC present atVNS as an optimal method to modulate NA in contrast to unselective drug acting on the noradrenergic system 49 .…”

“…Accordingly, considering all these facets, OUD might require and benefit from an approach encompassing multiple treatments, which will be able to enhance both clinical and cognitive outcomes supported by strong translational elements. Specifically, in the last decade, non‐invasive brain stimulation techniques have been proposed as an alternative neuromodulatory, but yet non‐pharmacological treatment for patients suffering from substance use disorder who fail to adequately respond to other treatment options 11–14 . At this point, repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) have been the target of previous investigations on brain stimulation intervention to treat OUD 15 .…”

“…Specifically, in the last decade, non-invasive brain stimulation techniques have been proposed as an alternative neuromodulatory, but yet non-pharmacological treatment for patients suffering from substance use disorder who fail to adequately respond to other treatment options. [11][12][13][14] At this point, repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) have been the target of previous investigations on brain stimulation intervention to treat OUD. 15 Here, we consider the potential use of auricular transcutaneous vagus nerve stimulation (atVNS) as an addition to MMT or stand-alone treatment for opioid withdrawal in China.…”