The study will compare two groups of patients: a control group of patients treated per the Standard of Care when prescribed with a medication for their Major depression disorder, versus a group of patients that used the Predictix Antidepressant tool when prescribed with a medication for their Major depression disorder by their treating physician. Success will be measured by the number (proportion) of responders per group.

The study will be comprised of two arms:

1. PGT arm - Predictix Antidepressant-guided treatment condition
2. SOC (control) arm - Standard of Care condition Eligible subjects will be assigned to one of the study arms at a 1:1 ratio and will be followed for a period of 12 weeks.

An assigned psychiatric expert will review and approve subject's eligibility prior to entrance to the study, as well as, the medication/s prescribed based on the Predictix report prior to treatment start.

During the 12 weeks of follow up , data will be collected at the following timepoints: Screening, Baseline (start of treatment) and at 4, 8 and 12 weeks.

Visits will include the completion of several questionnaires designed to answer the study objectives, either as self-reported by the patients and/ or by the physician.

Depression scores by the Quick Inventory of Depressive Symptomatology (QIDS 16) questionnaire and evaluation of all safety related endpoints will be analyzed following the completion of the 12 weeks visit procedures. In case of a change in treatment, as per the treating physician's decision, a new 12 weeks cycle of data collection will start. Two independent cycles are permitted per patient.

In addition, retrospective (6 months prior to enrollment) and long-term follow up period data (12 months post enrollment) will be analyzed, in order to evaluate the device use effect on patients care outcomes in terms of economic burden and Social impact, on patients, employers, the health care system and payers.

The analysis will be based on both the work productivity and activity impairment questionnaire and the patient's electronic medical data record.

Inclusion Criteria:

• Male and female at the age of 18 - 75 years old at time of screening.
• MDD diagnosis per DSM V at screening visit or prior to screening visit.
• Rule out other causes of depressive symptoms other than MDD.
• Ability to read, understand and sign an informed consent document
• Female subjects at reproductive age that are tested negative for pregnancy
• Women with childbearing potential (i.e., not post-menopausal or surgically sterilized) must agree to use adequate birth control methods during the whole study duration

Exclusion Criteria:

• Patient is currently on an antidepressant treatment.
• Patient is diagnosed with other major psychopathologies (i.e. schizophrenia, bipolar disorder, psychotic depression, geriatric depression).
• requires antipsychotic medication or mood stabilizers.
• Patient is at substantial suicidal risk as judged by the treating physician
• Patient has attempted suicide in the past year.
• Patient has any current unstable medical condition or surgical illness.
• Patient has history of seizure or convulsions.
• Patient has history of drug abuse or alcoholism in the last 6 months.
• Inadequate communication with the patient.
• Patient has participated in another clinical study in the last 30 days preceding this study.
• In the investigator's judgement, patient is not able to provide written informed consent and follow protocol requirements.