RecruitingBehavioural interventionCoaching as an Adjunct to Ketamine Therapy for Treatment-Resistant DepressionThis study is being conducted at Massachusetts General Hospital (MGH) to explore whether adding psychedelic coaching can enhance the effects of ketamine or esketamine maintenance treatment in individuals with treatment-resistant depression (TRD). The investigators are currently enrolling participants who are receiving ongoing maintenance intravenous (IV) ketamine or intranasal esketamine (Spravato) treatment at the MGH Ketamine Clinic. Participation in the study will involve adding coaching sessions to your existing ketamine maintenance treatment.