Trigeminal Nerve Stimulation in Treatment-resistant Generalized Anxiety Disorder: a Feasibility Study

Inclusion Criteria:

• Meet the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM5)criteria for generalized anxiety disorder.

• Subjects on a stable dose of an selective serotonin reuptake inhibitor (SSRI) orserotonin and noradrenaline reuptake inhibitor (SNRI) for at least 8 weeks.

• Treatment-resistant - treatment resistance will be defined as lack of response to atleast two drugs, from two different classes of drugs considered first-line orsecond-line for GAD. Only trials lasting at least 8 weeks, and with at least theminimum 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 obsessive compulsive disorder (OCD), PTSD, bipolar disorder,schizophrenia, schizoaffective disorder, personality disorders, substance usedisorders, intellectual disabilities and dementia or other neurological diseasesincluding trigeminal neuralgia

• Pregnant or breastfeeding women

• Participants who are experiencing seizures

• Implanted vagal nerve stimulation (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 3drinks per week

• Consumption of natural health products that may affect anxiety or depressionsymptoms