William Walsh, Ph.D., is president of the non-profit Walsh Research Institute near Chicago and a key scientist driving the development of nutrient-based psychiatry.  His book, Nutrient Power, which describes an evidence-based nutrient therapy system, is the result of his over 30 years of research and clinical experience.   He directs an international physician-training program in the U.S. and in Australia teaching advanced biochemical/nutrient therapies which are used by over 500 doctors throughout the world.