Electrical Vestibular Nerve Stimulation (VeNS) as a Treatment for Major Depressive Disorder (MDD)

Inclusion Criteria: 1. Signed Informed Consent 2. Adults, (US ≥ 22 years and ≤ 80 years, UK ≥ 18 years and ≤ 80 years) male or female at the time of signing informed consent 3. Beck's Depression Inventory-ll (BDI-ll) score of ≥ 14 at Screening 4. Established diagnosis of depression as confirmed at the time of screening by the Mini-International Neuropsychiatric Interview (MINI) 5. A Generalized Anxiety Disorder (GAD-7) score \<10 at screening 6. On anti-depressant medication to treat depression (participant must only be on one Selective Serotonin or Norepinephrine Reuptake Inhibitor (SSRI/SNRI) for at least 1 year prior to baseline visit, and no longer than 5 years) 7. Stable dose of current prescribed antidepressant (SSRI/SNRI) medication to treat depression, 3 months prior to baseline appointment 8. Maintain a stable prescribed medication and/or treatment regime to treat depression for the duration of the trial 9. No change in regular medication for the duration of the trial (unless directed by a health care provider). 10. Can speak / read English 11. Ability and willingness to complete all study visits and procedures; in particular an agreement to engage with trying to use the device per the study protocol 12. Ability and willingness to adhere to 30 minutes usage of the device daily for the duration of the trial 13. Access to Wi-Fi for the duration of the study 14. Access to a computer, laptop, iPad, tablet or smartphone (to complete study visits and complete online study questionnaires) 15. Willingness to use a video calling platform to conduct remote study visits 16. Agree not to undergo any extreme lifestyle changes during the duration of the study that could impact mood e.g. dietary , exercise changes 17. Agree not to begin any complimentary or alternative therapies that may affect your mood during the time on the study e.g use of mental health apps, CBT Exclusion Criteria: 1. Risk of persistent self-harm or suicide as confirmed by the Columbia Suicide Severity Rating Scale (CSSRS) 2. Diagnosis or history of bipolar disorder 3. History of or a current psychotic disorder such as schizophrenia or other non-mood disorder psychosis 4. Diagnosis of substance use disorder within the past 12 months or current substance use dependence 5. Use of recreational drugs (e.g nalgesics, depressants, stimulants, and hallucinogens). Subject can enrol after a washout period of 30 days 6. Female who is pregnant or breast-feeding 7. History of diagnosed cognitive impairment / disorder such as delirium or dementia 8. Previous or current diagnosis of a chronic viral infection, for example hepatitis or HIV (potential damage to vestibular system, known as vestibular neuropathy). 9. History of stroke or head injury requiring intensive care or neurosurgery (potential damage to neurological pathways affected by vestibular stimulation) 10. Presence of permanently implanted batterypowered medical device or stimulator (e.g., pacemaker, implanted defibrillator, deep brain stimulator, vagal nerve stimulator, etc.) 11. History of epilepsy 12. History of severe tinnitus or vertigo 13. History of skin breakdown, eczema or other dermatological condition (e.g. psoriasis) affecting the skin behind the ears. 14. History or presence of malignancy within the last year (except basal and squamous cell skin cancer and in-situ carcinomas) 15. History of vestibular dysfunction or another inner ear disease 16. Regular use (more than twice a month) of antihistamine medication within the last 6 months. The subject can opt to switch to Fexofenadine (non-drowsy) and may enrol after a wash-out period of 2 weeks 17. Diagnosis of active migraines 18. Previous use of Modius device or any VeNS device 19. Participation in other clinical trials sponsored by Neurovalens 20. Participation in any other depression studies at the time of enrolment and throughout this study duration 21. Any other medical condition, or medication use, that in the opinion of the PI is likely to make the subject refractory to VeNS. 22. Failure to use device daily during trial participation (no more than 14 consecutive days usage drop without reasonable explanation) 23. Persistent failure to comply with study protocol and procedures