I've had various periods of depression over the years and I've spoken to enough people to know that there isn't a one-size-fits-all solution. In my experience, your twenties are some seriously hard work. Reality ain't quite like it was sold to you. What worked for me was getting busy to the point that there was no space for depression any more. I know that might sound a bit whatever but I've had various talk and drug therapies and they've been effective in varying degrees, temporarily. Being busy is more effective for me. As has been mentioned, charity work is a brilliant method.