During his life, Richard Carlson, Ph.D, was considered one of the foremost experts in happiness and stress reduction in the United States and around the world and was a frequent featured guest on many national television and radio programs. Don't Sweat the Small Stuff continued to be a publishing phenomenon with over twenty titles in the brand franchise, two of which were co-authored and authored with his beloved wife, Kris. He died of a pulmonary embolism in December 2006, at the age of forty-five.