RecruitingPhase 2Drug trialKetamine-Assisted Psychotherapy (KAP) Compared to Ketamine Alone for the Treatment of DepressionThe proposed study is a single-site, randomized, controlled clinical trial (RCT) comparing ketamine-assisted psychotherapy (KAP) to a standard evidence-based regimen of ketamine administered in a medical model without psychotherapy (KET). Eligible study participants will be adults with major depressive disorder (MDD). Adults with MDD will be randomized to KAP or KET in a 1:1 allocation. Each treatment group will receive KAP or KET over a period of four weeks. Measurement of depression severity, wellness, neurocognitive functioning and other parameters will occur at baseline prior to treatment, immediately following the end of the acute treatment period, and over an 8-week (two month) treatment follow-up period.