Apimostinel + Automated Neurocognitive Training for Depression

This study is testing whether a drug called apimostinel (a single IV infusion that works differently from standard antidepressants) combined with an automated computer-based brain training program can reduce negative self-thinking patterns in people with depression. **You may be eligible if...** - You are between 18 and 60 years old - You have been diagnosed with major depressive disorder (MDD) - Your depression severity score is 20 or higher on a standard scale - You have significant negative self-esteem or self-critical thinking - You are not currently pregnant and are using appropriate birth control **You may NOT be eligible if...** - You have bipolar disorder, psychosis, or autism spectrum disorder - You have used a specific type of antidepressant called an MAOI in the past 28 days - You have Parkinson's, Alzheimer's, Huntington's, multiple sclerosis, or a history of seizures or stroke - You are currently hospitalized in a psychiatric facility - You have active suicidal thoughts with intent or a plan - You have uncontrolled high blood pressure or kidney or liver problems - You take certain medications that interact with the study drug (ketamine-related drugs, memantine, some others) Talk to your doctor to see if this trial is right for you.