Physical Activity Program for TRD

This trial is testing whether a structured physical activity program can help people with treatment-resistant depression (TRD) — depression that hasn't improved after trying at least two antidepressants. Participants are currently sedentary (less than 60 minutes of moderate exercise per week) and are still on their current treatments. **You may be eligible if...** - You are between 18 and 65 years old and currently sedentary (very little regular exercise) - You have been diagnosed with major depressive disorder (not psychotic) and are in a current depressive episode - Your depression has not improved after at least two adequate antidepressant treatments - Your current treatments have been stable for at least one month - Your depression symptoms are at least mild (MADRS score of 7 or higher) **You may NOT be eligible if...** - You have current mania, hypomania, mixed episodes, or psychosis - You have had a substance or alcohol use disorder in the past 3 months - You are pregnant - You have had a cardiovascular event (heart attack, stroke) in the past 12 months - You have a medical condition that makes exercise unsafe Talk to your doctor to see if this trial is right for you.