After Matthew Perry’s death was announced, a clip of the actor debating the science of addiction on the BBC’s Newsnight programme went viral. To find out where we’ve got to in our understanding of addiction, Ian Sample talks to Dr Nora Volkow, director of the US National Institute on Drug Abuse. She explains how brain imaging has advanced our understanding of this chronic disease. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>
