The goal of this observational study is to learn about remote mental health monitoring technology for adults with treatment-resistant depression. The main question it aims to answer is: are digital mental health monitoring tools (an electronic data capture platform and wearable device (e.g., smartwatch or smart-ring)) feasible to implement alongside clinical treatment for depression? The secondary aim of this study is to inform preliminary clinical parameters for larger, definitive studies.

Participants receiving neuropsychiatric treatment (repetitive transcranial magnetic stimulation, intravenous ketamine, or electroconvulsive therapy) as part of their regular medical care for treatment-resistant depression in the Interventional Psychiatry Program will have their clinical assessment data entered into a digital platform and will wear an accessory-based wearable device for the duration of treatment.

This observational study with retrospective data analysis is conducted in patients with treatment-resistant depression (TRD) undergoing neuropsychiatric clinical treatment (rTMS, IVK, or ECT) in the Interventional Psychiatry Program (IPP) at St. Michael's Hospital. Participants will have scores from a self-report assessment of anxiety (GAD-7) and a self-report (PHQ-9) or clinician-administered (MADRS) assessment of depression completed as part of clinical care entered into the Research Electronic Database Capture (REDCap) web-based platform after each treatment session. This will facilitate retrospective analysis of mental health symptom change and treatment response over the course of treatment. Participants will also have the opportunity to wear an accessory-based wearable device (e.g., smartwatch or ring) throughout the course of treatment to passively capture physiological biometrics of physical and mental health (e.g., heart rate, temperature, sleep, activity). This two-year pilot study aims to recruit a total of 200 participants with TRD to retrospectively assess the feasibility and efficacy of integrating remote health sensing and monitoring platforms in psychiatric clinical care.

Inclusion Criteria:

• Adults (aged 18+) who are capable of giving informed consent
• Patients meeting diagnostic criteria for major depressive disorder (MDD) without psychotic symptoms according to the DSM-5
• Currently experiencing a major depressive episode (MDE)
• Montgomery-Asperg Depression Rating Scale (MADRS) score greater than 20 at screening
• Patients meeting criteria for treatment-resistant depression (TRD): failure of 2 or more adequate trials of antidepressant therapy of adequate dose and duration during the current episode
• Enrollment in one of the treatment modalities (rTMS, IVK, or ECT) at the Interventional Psychiatry Program at St. Michael's Hospital, Unity Health Toronto
• Ownership of a smartphone (for participants using wearable devices)

Exclusion Criteria:

• Individuals without Internet access (required to access study platforms)
• Medication changes, aside from the treatment received through the IPP, one month (28 days) before screening, or during the entire duration of treatment (variable based on treatment arm)
• Participants who do not speak English fluently enough to successfully communicate study information, answer questions accurately, and/or obtain informed consent

Adults suffering from treatment-resistant depression (TRD) who are being treated in the Interventional Psychiatry Program at St. Michael's Hospital, Unity Health Toronto. Patients have a confirmed diagnosis of Major Depressive Disorder (MDD) and are experiencing a Major Depressive Episode (MDE) at the time of enrollment.