Figure 2:

Study protocol for Transcutaneous Cervical Vagus Nerve Stimulation (tcVNS) in Opioid Use Disorder (OUD). Patients with OUD discontinued use of opioids by midnight of the night before the protocol. They presented early in the morning before initiation of Medication for Opioid Use Disorder (MOUD) initiation and underwent measurement of physiological variables with wearable sending devices (heart rate, respiratory variability) and behavioral variables with rating scales (withdrawal, pain, distress). tcVNS or sham was paired with opioid use cues (videos) in a double blind randomized fashion. There were significant increases in behavioral and physiological measures of withdrawal in the sham versus tcVNS group (i.e. tcVNS blocked measures of opioid withdrawal both subjective and objective related to sympathetic nervous system function).