This is so true... I have anxiety and depression and have always medicated it with physical activity. Used to be running, but BJJ feels even more effective because it's so cathartic to just FIGHT SOMEONE. It forces me to be really present and aware. I think a lot of people in our society are anxious not because we're "broken" but because we are designed to suffer more physical stress than we do in our day-to-day lives. Without the release of physically escaping a predator or something, we just hold it in and make ourselves sick. BJJ is a great proxy outlet. Plus, I've heard that activities that demand /concentration/ actually defuse anxiety and racing thoughts the best, and grappling definitely does that too.