By the early 1970s, the model of a substance abuser was the heavy drinker, the heroin addict, or the speed freak. Dr. Smith and his colleague Don Wesson and others created the West Coast Polydrug Abuse Treatment and Research Project to study a phenomenon they observed in San Francisco: a subset of people who used multiple drugs to the point of abuse. These patients presented new challenges for doctors due to the physiological interactions between the drugs as well as the interplay between the distinct subcultures surrounding the different drugs of abuse.