In short,
Inclusion Criteria:
* 22 - 70 years of age
* Diagnosis of Unipolar MDD (DSM-V)
* PHQ-9 score of ≥12 AND MADRS score of ≥ 20 at baseline
* Antidepressant medication ongoing
* If in psychotherapy, have maintained stable psychotherapy
* Have access to a smartphone or other device running Android 7.0+ or iPhone Operating System (iOS) 13+
* Be under the care of a psychiatrist or a primary care physician
* Allow communication between the investigators/study staff and any healthcare provider who currently provides and/or has provided service to the patient/subject within at least two years
* Provide the name and contact of at least two adult persons who reside within a 60-minute drive of the patient's residence.
* Be able to give voluntary, written informed consent to participate and have signed an Informed Consent Form specific to this study
* Be willing and able to comply with all study procedures
* Agree to meet all of the inclusion criteria throughout their participation in the study. Otherwise, the subject will be discontinued from the study
* Be able to understand, speak, and read English sufficient for the completion of trial assessments
Exclusion Criteria:
* Current state of mania or psychosis, or have a history of mania or psychosis.
* Treatment resistant depression.
* Are diagnosed with vitamin or hormonal deficiencies that may mimic mood disorders, as determined by the investigator.
* Be currently receiving any other interventional therapy for MDD other than a stable regimen of antidepressants or psychotherapy as defined in the inclusion criteria or have a history of electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), cranial electrotherapy stimulation (CES), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), or other brain stimulation.
* Have moderate or greater suicidality risk, or an attempt of suicide during lifetime or any previous hospitalization for suicidal behavior.
* Diagnosis of sleep apnea with prescribed treatment (unless they are on CPAP treatment and are compliant with treatment) or a diagnosis of insomnia that is unrelated to depression, as determined by the investigator.
* Have any structural lesion or any neurocranial defect or any other clinically significant abnormality that might affect safety, study participation, or confound interpretation of study results, as determined by the investigator.
* Have any implant in the brain (e.g., DBS) or neurocranium, or any other active implantable medical device anywhere in the body (e.g. pacemaker, insulin pump).
* Have a history of epilepsy or seizures.
* Have shrapnel or any ferromagnetic material in the head.
* Have any disorder that would impair the ability to complete the study questionnaires.
* Have been diagnosed with autism spectrum disorder.
* Have an alcohol use disorder or substance use disorder (past 12 months).
* Have a cognitive impairment (including dementia).
* medications that affect cortical excitability, as determined by the investigator.
* Have ever taken esketamine / ketamine for treatment of depression.
* Are currently admitted or have ever been admitted to a dedicated psychiatric ward for depression for a period of more than 24 hours.
* Have ever been diagnosed with obsessive-compulsive disorder (OCD) or bipolar type 1 or 2 disorder.
* Be diagnosed with PTSD, agoraphobia, anorexia or bulimia, panic or personality disorder, with active symptoms, based on the investigator's judgment.
* Have any history of myocardial infarction, coronary artery bypass graft (CABG), coronary heart failure (CHF), or history of other cardiac issues.
* Be currently experiencing or have a history of intractable migraines.
* Be a chronic nicotine user.
* Be currently pregnant or breastfeeding or planning to become pregnant or breastfeed any time during the study, or lack a medically acceptable method of contraception in females with child-bearing potential.
* Be currently incarcerated.
* Be participating concurrently in another clinical investigation or have participated in a clinical investigation within the last 90 days or intend to participate in another clinical investigation during the study.
* Have a hairstyle or hair type, such as very thick hair or voluminous hairstyle, that would prevent wearing of the treatment cap tightly enough on the head that the electrodes are held close to the scalp.
