Effects of chemical castration on sex offenders in relation to the kinetics of serum testosterone recovery: implications for dosing schedule

J Sex Med. 2014 May;11(5):1316-24. doi: 10.1111/jsm.12492. Epub 2014 Feb 27.

Abstract

Introduction: A growing number of countries are adopting chemical castration as treatment and penalty for sex offenders.

Aim: The aim of this study is to evaluate the outcome of chemical castration of sexual offenders with a focus on the kinetics of serum testosterone (T) recovery.

Methods: This prospective analysis included 56 sex offenders imprisoned for sexual offenses at the National Forensic Hospital. Thirty-eight and 18 patients who received 3 and 6 months of leuprolide acetate injections were assigned to group A and group B, respectively.

Main outcome measures: To evaluate treatment efficacy according treatment duration, psychobehavioral assessments and serum T levels were serially measured during the on-cycle and the following observational 12-month off-cycle.

Results: Chemical castration and the associated decrease in serum T levels reduced the frequency and intensity of sexual thoughts in 76% and 71% of group A patients and in 78% and 72% of group B patients, respectively. Reductions in masturbation frequency were observed in 74% of group A and 83% of group B patients. The median Wilson's Sex Fantasy Questionnaire (SFQ) scores were also significantly reduced in both groups. In group A, an upsurge of serum T to the flare level was observed during the first 2 months of the off-cycle, accompanied by an intense sexual drive and fantasy. In group B, serum T gradually recovered to the baseline level and continued to upsurge beyond baseline levels during the observational period. SFQ scores of group A returned to pretreatment levels following the observational period; however, SFQ scores of group B remained suppressed. Lack of objective assessments for psychobehavioral outcomes was a limitation.

Conclusions: The efficacy of chemical castration varied according to the treatment duration. Regarding the kinetics of serum T recovery, maintaining at least 6 months of treatment warranted stable control of an excessive sexual drive following treatment cessation.

Keywords: Behavior; Castration; Paraphilia; Sex Offender; Testosterone.

MeSH terms

  • Adolescent
  • Adult
  • Androgen Antagonists / administration & dosage*
  • Androgen Antagonists / pharmacology
  • Castration / methods*
  • Fantasy
  • Humans
  • Leuprolide / administration & dosage*
  • Leuprolide / pharmacology
  • Libido / drug effects
  • Male
  • Masturbation / physiopathology
  • Middle Aged
  • Prisoners
  • Prospective Studies
  • Sex Offenses*
  • Sexual Behavior / drug effects
  • Surveys and Questionnaires
  • Testosterone / metabolism*
  • Treatment Outcome
  • Young Adult

Substances

  • Androgen Antagonists
  • Testosterone
  • Leuprolide