Referring to long-acting naltrexone implants and injections, another hot topic explored the “curious possibility that precisely because a technology is (relatively) effortlessly effective, it is to that degree under suspicion”. That was in relation to opioid use treatment in general; here we focus on convicted offenders, and ask: Are we missing a trick by not pressuring opioid-dependent offenders under supervision to take the pills or be implanted/injected with naltrexone?

Particularly for offenders, naltrexone seems the perfect medication for promoting abstinence from heroin and allied drugs – a pill taken daily or just twice a week which makes heroin use a disappointment rather than a ‘high’. Free itself of psychoactive effects, naltrexone commandeers and blocks the neural receptors targeted by opiate-type (‘opioid’) drugs. A chemical instead of a physical shackle, it seems in tune with the deprivation of liberty imposed on offenders because it deprives them of opioid experiences rather than providing these in the form of substitute opioids. At its most optimistic, the hope and expectation is that long-acting naltrexone implants will result in patients “learning to abstain successfully”, likened to learning to speak a foreign language fluently in that “It is not enough simply to know the foreign words, or the social and psychological techniques for resisting temptation. What matters is practice and the ability to use those words or techniques not just correctly and appropriately but automatically”. However, lasting effects are not necessarily critical to treatment linked to a probation or parole order. Judges just need to be persuaded that treatment is likely to do as good a crime-prevention job as prison – that it will prevent or keep offending to a minimum for as long as the offender would have been locked up, rarely more than a year for non-violent drug-related offences.

Yet compared to substitute medications like methadone, naltrexone is rarely used inside or outside the criminal justice system. One reason is a limitation applicable to any medication which deprives patients of valued experiences: the more effective it is, the more patients simply refuse it or quickly abandon the treatment. Again this seems to make the treatment suitable for sentenced offenders, by definition already coerced into doing things they would not otherwise do. Let’s examine this apparently suitable marriage between treatment and patient, and ask ourselves if by under-using it, we are missing what could be the most effective way yet to break opioid-dependent offenders of a crime-generating habit.