Effects of Chemical Castration on Sex Offenders in Relation to the Kinetics of Serum Testosterone Recovery: Implications for Dosing Schedule

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. Koo KC, Ahn JH, Hong SJ, Lee JW, and Chung BH. Effects of chemical castration on sex offenders in relation to the kinetics of serum testosterone recovery: Implications for dosing schedule. J Sex Med 2014;11:1316–1324.