The heroin overdose items assessed any lifetime non-fatal overdose due to heroin, and any lifetime overdose due to heroin requiring medical treatment (the variable used in this study). The suicide section assessed lifetime occurrence of suicidal thoughts, persistent suicidal thoughts (7 days or more in a row); suicide plans, suicide attempt, and number of suicide attempts. The criminality and incarceration items asked participants if they’d ever been in prison, the total length of time in prison, the longest period of time in prison, if they’d ever been arrested for anything other than traffic offences, if they’d ever committed a crime for which they hadn’t been arrested, and the nature of the crime/s committed. The relapse variables included whether the participant had ever relapsed to heroin use after a period of abstinence, and the reason for the relapse. Adult violence (after age 18) assessed whether the participant had ever been the victim or perpetrator of various forms of assault (e.g. pushing, hitting, punching, kicking, strangling) or threats of violence (hitting, threatened with a weapon), or had experienced unwanted sexual activity through the use of violence, threats of violence, blackmail, or threats of relationship break-up.
