The role of central and peripheral hormones in sexual and violent recidivism in sex offenders.

Hormonal factors are important in multifactorial theories of sexual offending. The relationship between hormones and aggression in nonhumans is well established, but the putative effect in humans is more complex, and the direction of the effect is usually unclear. In this study, a large sample (N = 771) of adult male sex offenders was assessed between 1982 and 1996. Gonadotrophic (follicle-stimulating hormone and luteinizing hormone) and androgen hormone (total and free testosterone; T) levels were assessed at Time 1, along with indicators of sex drive and hostility. Individuals were observed up to 20 years in the community, with an average time at risk of 10.9 years (SD 4.6). Gonadotrophic hormones correlated positively with self-reported hostility and were better predictors of recidivism than was T (area under the curve (AUC), 0.58-0.63). Self-reported hostility emerged as a partial mediator of this relationship between gonadotrophic hormones and recidivism. These results point to a potentially new area of investigation for hormones and sexual aggression.