For some prisoners with problematic sexual arousal (PSA), “images of sex flood their minds” all of their waking hours, according to Prof Belinda Winder, a leading forensic psychologist who has evaluated the use of drugs to control libidos.
“I remember talking to one guy a few weeks after he started taking the medication. He said: ‘It’s amazing. I followed a film plot. I wasn’t just looking for when I could see bra straps, when I could see nipples, when someone’s going to bend over so I could see their bum.”
“Without the drugs, these images were going around his head all the time. He did not want them any more,” she said.
Drugs used in the UK to treat PSA include antidepressants, which help control obsessive urges, and anti-androgens, which lower testosterone levels.
The treatments, typically taken as pills, are not suitable for some offenders such as those who are primarily motivated by anger, or who struggle to moderate their behaviour while using alcohol or drugs.
A similar approach has been used in some European countries. In Denmark and France, the use of chemical suppression has only been administered on a voluntary basis.
In Germany, the Dunkelfeld project provides free and confidential therapies including medical interventions to men with paedophilic or hebephilic obsessions.
An advert on YouTube urging men to contact the project shows unidentified men saying: “In therapy, I learned that no one is to blame for their sexual preference. But everyone is to blame for their behaviour. I don’t want to be an offender.”
But many other countries have taken a harder line. Poland introduced mandatory chemical suppression for some sex offenders.
South Korea became the first country in Asia to legalise chemical castration, passing a law in 2010. The law grants courts and a Ministry of Justice committee the authority to order involuntary hormone treatment for convicted sex offenders to suppress their testosterone.
In Australia, several states grant courts and parole boards the power to order anti-libidinal treatment for high-risk sex offenders which can then become a condition of release. Kazakhstan and a number of US states including California and Florida already have mandatory prescribing of anti-libidinal drugs to some sex offenders.
Officials in the UK have explored whether taking part in programmes such as these could be made a condition of a parole licence, similar to a scheme in California. However, ethical dilemmas remain over whether it would be right to give someone parole based on whether they take a drug that can be life-changing.
In the 50s, hormone treatments were given to men convicted of crimes related to their homosexuality with the promise that they could avoid jail. Alan Turing, the computer scientist and codebreaker, who was convicted of “gross indecency” in 1952, accepted chemical castration as a way of avoiding imprisonment. He took his own life two years later and received a posthumous royal pardon in 2013.
The side effects of anti-androgens in particular can be severe. Some men experience fatigue, hot flushes, muscle loss, mood changes, weight gain and a loss of bone density.
Experts acknowledge that problems remain. The medication is not a cure and does not change underlying behaviours. Some programmes have high drop-out rates.
Each offender would have to be assessed by the Parole Board on their merits, according to Winder. “It is never going to be so simple that a decision will be taken on whether to give someone parole based on whether they are taking their meds,” she said.
Winder added: “Parole Boards take such decisions by assessing many factors, including how receptive they are to staff and how they interact with their peers. It is really important that people are trained in understanding what it means if someone is taking this medication and how that might affect a person’s behaviour.”