Easy answer - EXERCISE! Here's a CNN article that proves it!  Not only does exercise help you physically but it also helps keep you mentally in check. 

After years of working at Pop Physique mastering barre method, this amazing teacher, friend and inspiring female, Miz Shawana, has ventured on her own to teach the world how to stay fit effectively and keep it fun all while enabling her students to walk away happier. She essentially brings joy to each person who attends her class. 

Check out her website and I strongly encourage you to take a class with her. I guarantee some soreness with a smile.