He later attended Yale School of Medicine and ultimately became Professor of Psychiatry at Yale until 1966 when he left Yale to become Chairman of the Psychiatry department at the University of Chicago where he continued his psychopharmaceutical research, primarily concerned with 5-hydroxytryptamine (serotonin).
He attended Yale School of Medicine and became a Professor of Psychiatry at Yale until 1966 when he moved to the University of Chicago to become Chairman of their Psychiatry department. His work in psychopharmaceutical research, particularly focused on 5-hydroxytryptamine (serotonin), continued after his move.