Throughout his career, Lewis has worked to bring indigenous concepts of health and healing into the contemporary practice of medicine and psychology. He has found the narrative paradigm and social constructionism to be most exciting ways to bridge indigenous people and contemporary psychology. He is the author of five books in these areas, the most recent of which is Healing the Mind through the Power of Story: the Promise of Narrative Psychiatry. His first book was Coyote Medicine.
Lewis received his M.D. degree from Stanford University in 1975 and his Ph.D. in clinical psychology from the Psychological Studies Institute in Palo Alto, California, in 1980. He has a postgraduate diploma in narrative studies from Massey University in New Zealand. He completed residencies in family medicine and in psychiatry at the University of Vermont. He completed post-doctoral studies at the University of California at Berkeley in alcohol research and at the Center for Recovery from Illness in neuropsychology. Lewis is American Board Certified in Family Medicine with added qualifications in geriatrics and in psychiatry.
At UI&U, Lewis teaches courses related to research methods, biological aspects of psychology, and narrative studies. He is especially interested in the brain as a social organ, its social construction, and the role of epigenetics and neuroplasticity in regulating mood and behavior.