Trigeminal Nerve Stimulation in Treatment-resistant Generalized Anxiety Disorder: a Feasibility Study
This is a feasibility study for trigeminal nerve stimulation (TNS) in patients with treatment-resistant generalized anxiety disorder (TR-GAD). Ten participants will receive TNS for 8 weeks as an augmentation strategy to pharmacological treatment for generalized anxiety disorder (GAD).

The primary objective is to ascertain if TNS is a safe and well-tolerated treatment for patients with TR-GAD.
The secondary objective will be to monitor changes in GAD symptom severity throughout the study.

Results from this study will inform a randomized controlled trial to be conducted in the future.
- EligibilityCriteria: Inclusion Criteria:  Meet DSM5 criteria for generalized anxiety disorder. Subjects on a stable dose of an SSRI or SNRI for at least 8 weeks. Treatment-resistant - treatment resistance will be defined as lack of response to at least two drugs, from two different classes of drugs considered first-line or second-line for GAD. Only trials lasting at least 8 weeks, and with at least the minimum effective dose of the given medication will be considered failed trials.  Exclusion Criteria:  Moderate to severe major depressive disorder Moderate to high suicidality Diagnosis of OCD, PTSD, bipolar disorder, schizophrenia, schizoaffective disorder, personality disorders, substance use disorders, intellectual disabilities and dementia or other neurological diseases including trigeminal neuralgia Pregnant or breastfeeding women Participants who are experiencing seizures Implanted VNS or other electrical devices Participants who are already undergoing transcutaneous electrical nerve stimulation Consumption of cannabis, any cannabis by-products, illicit drugs, or alcohol above 3 drinks per week Consumption of natural health products that may affect anxiety or depression symptoms - HealthyVolunteers: No - Gender: All - MinimumAge: 18 Years - MaximumAge: 65 Years - StdAgeList: Adult, Older Adult