 Depression is a functional evolutionary tool that forces action unless it's too strong. Now depression is a complex concept. Dr. Bus has controversial views and non-controversial views, but one of them is depression is functional if it's not too strong. It's kind of like lifting weights is good. Lifting, benching 300 pounds or 200 pounds is good. It's putting it's putting stress and tearing muscle fibers a little bit in the process of hypertrophy, but since it's not too heavy, it's actually functional. Same with depression. If it's too strong, it's like having an 800 pound bench press. You can't do it and it actually pulls the muscle.