An Open-Label Study to Evaluate the Safety, Tolerability and Pharmacodynamics of BPL-003 in Patients With Treatment Resistant Depression

This study tests a new experimental therapy called BPL-003 for people with treatment-resistant depression (TRD) — meaning their depression has not improved after trying at least two antidepressant medications. Researchers want to understand how safe and effective this new treatment is. **You may be eligible if...** - You have been diagnosed with Major Depressive Disorder (MDD) - Your depression has not responded to at least 2 antidepressant medications in the past 5 years - Your depression symptoms are currently severe (based on a standard rating scale) - You are currently taking one of these antidepressants: citalopram, escitalopram, sertraline, or fluoxetine - You are willing to stop your current antidepressant as part of the study **You may NOT be eligible if...** - You have schizophrenia, bipolar disorder, psychosis, or a personality disorder - You have a family history of certain psychiatric conditions (schizophrenia, bipolar disorder) - You have a current alcohol or drug use disorder - You have previously not responded to ketamine, electroconvulsive therapy (ECT), vagal nerve stimulation, or deep brain stimulation - You have had suicidal thoughts with intent to act within the past 12 months Talk to your doctor to see if this trial is right for you.