Coaching as an Adjunct to Ketamine Therapy for Treatment-Resistant Depression

Inclusion Criteria: 1. Age 18 years or older at the time of informed consent/study enrollment. 2. Ability to understand and provide informed consent. 3. Fluent in English (spoken and written). 4. Willingness to have coaching sessions recorded via HIPAA-compliant MGB approved video-based platform. 5. Has a QIDS-SR score ≥ 11, indicating at least moderate depressive symptom severity at screening visit. 6. Lifetime diagnosis of a depressive disorder according to the MINI. 7. In the maintenance phase of ketamine or esketamine treatment, defined as the period following the initial acute treatment series (typically 2 treatments per week for 3 weeks). 8. Patients must have completed at least 3 maintenance treatments prior to screening visit with a QIDS-SR score ≥ 11 noted from EPIC medical records from the 3 most recent maintenance treatments. 9. Currently receiving maintenance IV ketamine or intranasal esketamine at the MGH Ketamine Clinic, with at least one treatment administered within the past 8 weeks, and planning to continue to be an active patient at the MGH Ketamine Clinic for the duration of the study. 10. Has established care with a mental health provider (e.g., psychiatrist, therapist, or other licensed mental health clinician), and, if outside the MGB-healthcare system, agrees to sign a Release of Information form (ROI) with the study team. Exclusion Criteria: 1. Presence of an unstable medical condition, as determined by the study clinician. 2. Significant neurocognitive impairment that impairs with individual's ability to maintain ADLs and would interfere with study participation, per study clinician judgment. 3. Newly initiated psychotherapy within the past 3 months. 4. Any condition or circumstance that, in the judgment of the Principal Investigator, makes participation unsafe or unsuitable. 5. Any psychiatric condition that is currently primary, clinically predominant to their depression, or insufficiently stable such that it would interfere with study participation, per clinician judgment. 6. Plan to switch from IV ketamine treatment to intranasal esketamine or plan to switch from intranasal esketamine to IV ketamine treatment at any point during study. 7. Suicidality determined by the judgment of the study clinicians at screen, with a plan to act in next 6 months. 8. A ≥25% reduction in QIDS total score from screen to baseline visit.