The risk of some men sexually abusing children could be quickly reduced by a drug that lowers testosterone levels, researchers have found.

The team behind the project, which was put up for crowdfunding four years ago, said the drug – degarelix acetate – produced the results in men with paedophilic disorder in just two weeks. The drug was developed as a treatment for prostate cancer treatment and blocks the production of testosterone.

“We finally have something to offer that has a quick-acting effect,” said Dr Christoffer Rahm, a psychiatrist and researcher at the Karolinska Institute in Sweden, who led the study.

Rahm said the project is aimed at preventing risk to children, as well as improving the lives of men experiencing attraction to minors – an approach he says complements the work of police and others.

While such interventions, sometimes known as chemical castration, can be controversial, Rahm said the most controversial thing was not to do research in the field. “I think we should put more energy into investigating this field from a scientific perspective and from a medical, psychiatric perspective,” he said.

Scientists seek crowdfunding for paedophilia drug trial Read more

The new study, published in the journal Jama Psychiatry, reports how the team recruited 52 men from callers to a national telephone helpline called PrevenTell, which helps people who self-identify as having unwanted sexuality, who were subsequently diagnosed with paedophilic disorder.

The team assessed the men’s risk of committing child abuse, using a mix of self-reporting and psychological testing, taking into account a range of issues from sexual preoccupation to impaired self-regulation.

The researchers then put the men into two groups, one of which received two injections of a placebo while the other group received two injections of degarelix acetate, with the men unaware of which they received. Two weeks later, the men’s risk of committing child abuse was re-assessed.

The team found that, relative to the placebo group, the men treated with degarelix acetate showed a fall in risk level, in particular showing a reduction in high sexual desire and attraction to children, although not impaired self-regulation. The effects were still present, if not stronger, at 10 weeks, with many men saying they wanted to continue with the medication.

The drop was only deemed clinically significant in the small number of participants who were originally classified as at high risk of child sex abuse.

Dr Michelle Degli Esposti of the University of Oxford, who was not involved in the work, said developing effective treatments for individuals with paedophilic disorder was important. But she cautioned that the study involved only a small, self-selected group of men.

Also the study did not look directly at whether the drug reduces the occurrence of child sexual abuse itself, said Degli Esposti, adding: “This limits the generalisability of the findings and its potential wider benefits in tackling child sexual abuse.”

She said the study also raised ethical questions, asking: “Should we be focusing on medicating individuals who have sexual desire for children and, if so, do we expect these individuals to take drugs that have known side-effects? Or should we instead be focusing on tackling the upstream societal and structural factors that place children at risk of being sexually abused?

“It may not be a question of either/or, and such questions go beyond the findings of this specific study, but it is important to consider the implications of medicalising profound societal problems such as child sexual abuse.”

Donald Grubin, emeritus professor of forensic psychiatry at Newcastle University, said other drugs are already used to reduce testosterone levels, while the findings of the new study need to be replicated.

But, he said, the trial is well designed and degarelix acetate appears to act faster than current drugs – although safety and efficacy must be explored further. Like Degli Esposti, he noted that the study looked at changes in sexual thinking, not sexual offending, saying: “While it is reasonable to expect the former to impact the latter, this is very difficult to demonstrate given the long follow-up time required to do so and a reluctance to prescribe high risk sex offenders with a placebo in a community setting.”