Loss of treatment benefit when heroin-assisted treatment is stopped after 12 months

•A randomized controlled trial compared heroin-assisted treatment to methadone.•Participants in heroin-assisted treatment significantly decreased street heroin.•As planned, heroin-assisted treatment was discontinued after 12 months.•Three months after, participants significantly increased their street heroin use.•Heroin-assisted treatment must be an open-ended treatment.

PurposeIn 2013, during a recent heroin-assisted treatment trial, participants in heroin-assisted treatment (HAT) decreased significantly more their street heroin use than participants in oral methadone treatment. After the trial, HAT was discontinued. To examine whether the treatment benefits were sustained three months after the trial, the use of street heroin by the participants was analyzed in a follow-up study.ResultsAt the follow-up assessment, street heroin use increased in the experimental group. The two groups no longer showed a significant difference (p = 0.55) in the level of street heroin use.ConclusionA predetermined and forced end of HAT was followed by a significant increase in the level of street level use.