The Wellness Monitoring for Major Depressive Disorder (MDD) study is a prospective, longitudinal, observational study aimed at identifying biomarkers of relapse in MDD. Results may help refine clinical approach to relapse management, and may ultimately help MDD patients sustain wellness while on antidepressant medication.

This study involves a naturalistic follow up of responders from the study entitled "Integrated biological markers for the prediction of treatment response in depression", or the CAN-BIND-1 study. In addition, this study is also open to other participants who completed other CAN-BIND studies, as well as remitters who meet the inclusion criteria. Since patients usually seek medical attention only after relapse has occurred, imminent precursors to relapse are not well known. In this study, participants who are currently responding to an oral antidepressant treatment regimen and/or therapeutic intervention will be monitored over a minimum period of 13 months, which provides a unique opportunity to discover near-term biomarkers of relapse.

The study is conducted in partnership with Janssen Research & Development and utilizes remote monitoring technology for data gathering.

Inclusion Criteria:

• Meet DSM-V criteria for Major Depressive Episode (MDE) in MDD as determined by MINI.
• MADRS total score of equal to or less than 14.
• In the current MDE, patient must currently be responding to an antidepressant medication or a combination of treatments for MDD.
• Willing and able to complete self-reported assessments via a study-specific smartphone (LogPad), including sufficient fluency in English.
• Willing to wear GT9X Link, a wrist-worn device for the duration of the study.

Exclusion Criteria:

• Axis I diagnosis, other than MDD, that is considered the primary diagnosis.
• Bipolar I or Bipolar II diagnosis (lifetime), MDD with psychotic features (lifetime), schizophrenia, or schizoaffective disorder.
• Presence of a significant Axis II diagnosis (borderline, antisocial).
• High suicidal risk, defined by clinician judgement.
• History of drug or alcohol use, with severity of at least moderate or severe, according to DSM criteria, within 6 months before screening.
• Presence of significant neurological disorders, head trauma, or other unstable medical conditions.
• Received an investigational drug (including investigational vaccines) or used an invasive investigational medical device within 90 days before screening or is currently enrolled in an investigational study.
• Has a condition for which, in the opinion of the investigator, participation would not be in the best interest of the subject (e.g. compromise well being) or that could prevent, limit, or confound the protocol-specified assessments.
• Subject is an employee of the investigator or study site, with direct involvement in the proposed study or other studies under the direction of that investigator or study site, or is a family member of an employee or the investigator.

Men and women between 18 to 65 years of age who have previously met DSM-V criteria for Major Depressive Episode (MDE) in MDD as determined by MINI, (1) who participated in CAN-BIND-1 protocol, (2) other CAN-BIND studies, and (3) other remitters who meet the inclusion criteria who are currently responding to antidepressant medication or a combination of treatments.

This study is funded in part by the Ontario Brain Institute (OBI). Data collected from this study is entered into a research database called "Brain-CODE", deployed at a High Performance Computer Virtual Lab (HPCVL). The HPCVL supports the regulatory-compliant (e.g., 21 CRF Part 11, HIPAA, PIPEDA) processes for securing privacy of healthcare data.