Transcutaneous vagus nerve stimulation improves emotional processing

Area of Science:

• Neuroscience
• Psychiatry
• Medical Devices

Background:

• Invasive vagus nerve stimulation (iVNS) is an approved treatment for major depressive disorder (MDD).
• Limited understanding of iVNS mechanisms hinders treatment stratification and response prediction.
• The afferent vagal nucleus projects to brain regions involved in emotional processing, suggesting a potential therapeutic target.

Purpose of the Study:

• To investigate whether acute transauricular vagus nerve stimulation (taVNS) can improve emotional processing in individuals with MDD.
• To assess the impact of taVNS on facial emotion recognition and self-reported emotional states.

Main Methods:

• A randomized controlled trial was conducted with 52 participants with MDD and 44 controls.
• Participants performed a facial emotion recognition task during taVNS and sham stimulation.
• Linear mixed-effect models were used to analyze the effects of taVNS on emotional processing.

Main Results:

• A baseline negative bias in emotion recognition was observed across all participants.
• Acute taVNS significantly improved the accuracy of detecting positive facial expressions.
• taVNS reduced the reporting of negative emotional states, with group-dependent effects on positive emotional states.

Conclusions:

• Acute transauricular vagus nerve stimulation (taVNS) impacts emotional processing irrespective of diagnosis.
• These acute effects may serve as a predictive marker for long-term taVNS treatment outcomes.
• Further research is needed to validate taVNS as a predictive marker for long-term therapeutic effects.