Review of: Landgren V et al, JAMA Psychiatry 2020;77(9):897–905

Pedophilia—the sexual attraction to prepubescent children—has no clearly effective treatment. A common pharmacologic intervention is gonadotropin-releasing hormone (GRH) agonists, which lower testosterone through receptor desensitization. However, by producing an initial flare-up of testosterone, this treatment can increase aggression and libido, which limits intervention through GRH agonists to supervised correctional settings.

A recent study evaluated the efficacy of degarelix (Firmagon) for pedophilia. In contrast to GRH agonists, degarelix is a GRH antagonist and decreases testosterone to castration levels within three days without a testosterone flare-up. In a three-year study, researchers randomly assigned 52 men with pedophilic disorder to one of two conditions: degarelix (n = 26) or placebo (n = 26).

Participants in the treatment group received two subcutaneous doses of 120 mg degarelix acetate; those in the placebo group received similar-appearing injections of saline. All participants kept a diary and underwent structured interviews at baseline, two weeks, and 10 weeks. Researchers measured efficacy outcomes across five domains: pedophilic disorder as defined by DSM-5, sexual preoccupation, impaired self-regulation, low empathy, and self-rated risk of offending.

Participants receiving degarelix scored significantly lower than the placebo group in scores of pedophilic disorder and sexual preoccupation. However, there were no group differences in the domains of impaired self-regulation, low empathy, and self-rated risk of offending. Post-hoc analyses revealed that 58% of the degarelix group denied sexual attraction to minors at 10 weeks—much more than the placebo group, at only 12%.

Adverse events of degarelix included transient injection site reactions and hepatobiliary enzyme level elevations. Two participants (8%) in the degarelix group experienced transient suicidal ideation.

CHPR’s TAKE
Men who commit sexual offenses against children generally report struggling with their sexual urges for 10 years before committing a sexual crime (Knack N et al, Int Rev Psychiatry 2019;31(2):181–194). Degarelix did not improve self-regulation or empathy or reduce the self-rated risk of offending, but it reduced sexual attraction to minors, worked quickly, and was well tolerated. Given that we have few options to treat pedophilic disorder, this may be a helpful intervention.