Chemical castration - will it stop reoffenders?
The Straits Times
Andy Ho Senior Writer
26 January 2013
A 23-YEAR-OLD woman gang-raped by six men on a moving bus in Delhi on Dec 16 last year died of her injuries in a Singapore hospital two weeks later. Public outrage saw India proposing the chemical castration of rapists.
On Jan 3, South Korea meted out that very sentence to a 31-year-old man convicted of raping several teenage girls.
Actually, "chemical castration" is a misnomer since the completely reversible procedure does not involve any mutilation of the genitalia at all. It simply involves (initially weekly) injections of a synthetic female hormone called medroxyprogesterone acetate (MPA), the primary use of which is as a female contraceptive.
To tame male sex offenders, it must be continued indefinitely. By contrast, in women, MPA is injected once every 12 weeks for birth control, for no more than two years at the most.
MPA reduces the blood levels of testosterone, the male hormone responsible for the libido, including deviant sexual urges. Less testosterone means the libido is curbed accordingly.
Besides loss of libido, MPA injections also lead to erectile problems and lowered sperm count. The dosage is adjusted so there are no spontaneous erections but the man may still have one if stimulated by a suitable partner.
In fact, some offenders on MPA continue to have erections, ejaculations and orgasms. Most claim it simply makes them not have sexual thoughts at all but some say they can have sex nevertheless, especially if they have Viagra. In India, where one can buy prescription drugs over the counter, sex offenders on MPA who can afford them will be able to buy drugs to overcome its libido- and erection-reducing effects.
Alternatively, if the offender absconds from treatment, his testosterone levels will return to normal over time and then he might not be able to control his deviant sexual urges. He might then reoffend.
MPA does cause some serious side-effects. In the short term, it leads to weight gain, diabetes, hypertension, insomnia, lethargy and sweating. He will lose muscle mass and gain weight, the testicles will shrink in size and, over the long run, his bones may become brittle.
While it surely reduces testosterone levels, it is not clear that an MPA programme will definitely reduce sexual reoffending rates. The studies that look at sexual reoffending rates with MPA are, in general, methodologically flawed and simply too small in size, while follow-up periods are usually too short, often because the drug's side-effects cause many an offender to abscond and drop out of the study.
One reasonably good study done in a United States MPA programme deserves attention. In this 2006 study published in Sexual Abuse: A Journal Of Research And Treatment, three groups of sex offenders were followed for five years after their release from prison to compare their recidivism rates.
In Group One were sex offenders who were assessed to need MPA and put on it. None of them re-offended sexually, which sounded like good news for MPA.
In Group Two were sex offenders who were evaluated to require MPA but, for differing reasons, were released from prison without being put on MPA anyway. Of these, 18 per cent reoffended.
In Group Three were sex offenders assessed as being ones for whom MPA would be of no worth. So they were released into the community without MPA. Of these, 15 per cent reoffended.
The 3 per cent difference in recidivism rates between Group Two and Group Three was not statistically significant.
That meant that Group Two for whom MPA was deemed to be of use and Group Three for whom MPA was deemed to be of no use both reoffended at the same rates.
This meant that experts assessing sex offenders before they are released could not really predict which ones would benefit from MPA to help reduce their chance of offending again.
Thus, other factors that reduce recidivism rates might be in play. If so, the reasons why none in Group One (who were on MPA) reoffended may have to do with factors other than the MPA injections per se.
In sum, MPA is no insurance against sexual recidivism. In fact, a comprehensive review found "the professional literature... very curious" in the sense that the evidence that MPA programmes reduce sexual recidivism was "remarkably weak (and) empirically unsupported (but yet) many respected and experienced clinicians, while acknowledging this, are strong proponents".
Denmark, Sweden, Finland and Norway have had castration laws on their books for decades. Since 2010, Poland, Russia, Estonia and Moldova as well as South Korea have joined the club. Nine states in the US also have such statutes on their law books.
However, since it is unclear if MPA programmes actually reduce sexual recidivism, any nation contemplating chemical castration must weigh carefully, first, whether it is an inherently cruel and unusual form of punishment disproportionate to the crime's magnitude, or not; and, secondly, whether sexual recidivism can be reduced with methods like psychotherapy and electronic monitoring that are less drastic than an MPA programme.
Such questions, however, cannot be answered well when passions are inflamed in the midst of a great outcry against some heinous sex crime. More time is needed and cooler heads must prevail.