In the proposed investigation, the investigator will develop pilot data for the use of tVNS (transcutaneous vagal nerve stimulation) to enhance efficacy of exposure and response prevention therapy (ERP) to improve treatment success in patients with OCD. This data will include tolerability information from therapists and patients with OCD, effect sizes on real world clinical outcomes for the combinatory treatment, and mechanistic data on brain changes associated with treatment.

Inclusion Criteria:

• Adults between the ages of 18 and 55
• Meet DSM-5 criteria for OCD, based on a structured clinical interview and who have a YBOCS score of 15 or higher, indicating at least moderate OCD severity
• Participants must be willing and able to provide informed consent.

Exclusion Criteria:

• Participants with major neurological conditions, autism spectrum disorder, psychosis, major uncorrected sensory deficit, and severe medical disease that may be associated with neurological effects.
• People with an active eating disorder that requires treatment, but we will not exclude people who are in remission.
• Current illicit or prescription drug abuse
• Participants who are receiving pharmacotherapy for their OCD or for other psychiatric disorders will not be excluded
• No medication changes will be allowed during the study, and participants must be on stable doses of medications for at least 6 weeks prior to entering the study. Prior ERP treatment (at least 12 months removed) is acceptable