Dr. Peter Grinspoon, an addiction specialist who is on the faculty of Harvard Medical School, discusses his book "Aging Well with Cannabis: Feel Better, Sleep Better, and Live Better with Marijuana and CBD." Dr. Grinspoon has long advocated for medical marijuana, as did his father (Dr. Lester Grinspoon) before him. The book explores both the potential benefits as well as the potential hazards of using medical marijuana.