Assessment of the Efficacy and Safety of Fecal Microbiota Transplantation (FMT) in Patients With Major Depressive Disorder

This study is testing whether fecal microbiota transplantation (FMT) — a procedure that transfers healthy gut bacteria from a donor into a patient's gut — can help people with major depression who haven't responded to standard antidepressant medication. Researchers believe gut health may play a role in mental health. **You may be eligible if...** - You are between 18 and 65 years old - You have been diagnosed with major depressive disorder (a single or recurring episode) according to standard psychiatric criteria - Your depression symptoms are moderate to severe (high score on the Hamilton Depression Rating Scale) - You are not currently on depression medication for your current episode - You are willing to start treatment with escitalopram (an antidepressant) - Your symptoms did not improve enough after 2 weeks of escitalopram at the maximum tolerated dose - You have at least a primary school education level **You may NOT be eligible if...** - You have been diagnosed with bipolar disorder, schizophrenia, or a substance use disorder - You have prominent psychotic symptoms such as hallucinations or delusions - You are pregnant, breastfeeding, or have serious suicidal thoughts Talk to your doctor to see if this trial is right for you.