Research published in 2006 on prisoners’ perspectives on methadone maintenance in Scottish prisons, which has grown considerably in recent years, gives a useful insight into these issues and identifies some of the benefits that prisoners have experienced.

Methadone prescribing is a way of sustaining continuity of treatment for those who were already being maintained before. It can pave the way to maintenance treatment in the community on release. It increases tolerance to opioids. This increased tolerance reduces the risk of fatal overdose for those people who start to use heroin again when they leave prison and take the amounts that they were taking beforehand, not realizing that their tolerance may have been severely reduced while they were abstinent in prison. At the most basic level, methadone can stabilise prisoners who might otherwise attempt suicide or self-harm if required to deal with both imprisonment and abstinence at the same time.

See, for example, A Taylor et al, ‘The role of methadone maintenance in Scottish prisons: prisoners’ perspectives’, Scottish Prison Service, 2006.