Focused Ultrasound Neuromodulation in Patients With Treatment-Resistant Depression

This study is testing focused ultrasound (FUS) neuromodulation — a non-invasive technique that uses sound waves to gently stimulate specific brain areas — in people with treatment-resistant depression (depression that has not improved after trying multiple standard treatments). The goal is to see whether this brain-stimulation approach can safely reduce depression symptoms. **You may be eligible if...** - You are between 18 and 65 years old - You have been diagnosed with major depressive disorder (MDD) - Your depression score is above 20 on the standard Hamilton Depression Rating Scale - You have tried at least two different antidepressant medications at appropriate doses without sufficient improvement - You have also tried at least 6 weeks of cognitive behavioral therapy or psychotherapy - You have been on a stable medication regimen for at least 30 days **You may NOT be eligible if...** - You are pregnant or planning to become pregnant during the study - You have a moderate or severe substance use disorder (alcohol or drugs) - You have an active seizure disorder or a significant brain injury - You have an unstable medical illness - You cannot have an MRI (e.g., due to a pacemaker) - You have severe claustrophobia that prevents MRI Talk to your doctor to see if this trial is right for you.