"I am an unapologetic drug user. I take drugs as part of my pursuit of happiness, and they work. I am a happier and better person because of them. I am also a scientist and a professor of psychology specializing in neuroscience at Columbia University, known for my work on drug abuse and addiction. It has taken me more than two decades to come out of the closet about my personal drug use. Simply put, I have been a coward."