For a heroin addict, recovery is a life-long process. Philip Seymour Hoffman had been clean for 23 years before he relapsed in 2013, and died from an apparent overdose last week.To many people who have never grappled with addiction, it can be difficult to comprehend the desperate desire to use, even after so many years sober. To gain deeper insight into drug addiction, we asked recovering heroin users to share their experiences with us. Nearly 300 people responded, describing their struggle to get clean, and the ongoing battle to stay sober. Here, we publish a selection of those responses.