Functional Electrical Stimulation for MDD

Prior treatment

• Metallic orthopedic implants in the mouth (e.g., plates or screws).
• Current fibromyalgia or currently receiving or have received rTMS within the last 28 days before the screening.
• Unable to produce "Duchenne marker" expression with FES, secondary to any type of neurological condition or previous botulinum toxin treatments of facial muscles.

Other illness

• History of epilepsy or seizures.
• History of treatment-resistant depression (TRD) with history of ECT, Magnetic Seizure Therapy, Intravenous Ketamine use in the past or failure of \>2 antidepressant treatments of adequate duration and dose during the current episode.
• Past or current symptoms of mania, hypomania, mixed episodes, psychotic disorders, obsessive-compulsive disorder, post-traumatic stress disorder, active substance abuse or dependence (excluding nicotine and caffeine), neurodegenerative disease, or dementia. This will be confirmed on the MINI (77) administered by a trained research assistant.

Other

• Patients will be excluded if they:
• Damage or dysfunction of facial nerves.
• Current suicidal intent or plan as demonstrated by a score of ≥4 on MADRS item 10.
• Unable to understand instructions in English.

• Patients will be included if they:
• Meet the DSM-5 criteria for unipolar MDD with a current MDE without psychotic features, with ≤ 2 failed treatment trials (non-treatment-resistant depression), validated by MINI done by a trained research assistant.
• Have no change in the medication regimen or other forms of treatments (e.g., psychotherapy) for at least 4 weeks (28 days) prior to beginning the study, and have no plan to change them during the 20-session treatment period (14 days), and the 4-week post-treatment observation period. This will be established through self-report, in combination with the ATHF filled out by the participant.
• Have an MDD diagnosis as confirmed by the MADRS score of ≥7.
• Age group between 18 and 70 years of age