Sex offenders traditionally are managed by the criminal justice system, but psychiatrists are frequently called on to assess and treat these individuals. Part of the reason is the overlap of paraphilias (disorders of sexual preference) and sexual offending. Many sexual offenders do not meet DSM criteria for paraphilias,1 however, and individuals with paraphilias do not necessarily commit offenses or come into contact with the legal system.
As clinicians, we may need to assess and treat a wide range of sexual issues, from persons with paraphilias who are self-referred and have no legal involvement, to recurrent sexual offenders who are at a high risk of repeat offending. Successfully managing sex offenders includes psychological and pharmacologic interventions and possibly incarceration and post-incarceration surveillance. This article focuses on pharmacologic interventions for male sexual offenders.
Reducing sexual drive
Sex offending likely is the result of a complex interplay of environment and psychological and biologic factors. The biology of sexual function provides numerous targets for pharmacologic intervention, including:2
- endocrine factors, such as testosterone
- neurotransmitters, such as serotonin.
The use of pharmacologic treatments for sex offenders is off-label, and evidence is limited. In general, pharmacologic treatments are geared toward reducing sexual drive through nonhormonal or hormonal means (Table 1).3-5
Table 1: Pharmacologic treatment of male sex offenders: A risk-based approach
*Not available in the United States
†Some authors suggest administering this dosage once every 2 weeks
CPA: cyproterone acetate; GNRH: gonadotropin-releasing hormone; IM: intramuscular; MPA: medroxyprogesterone acetate; SSRI: selective serotonin reuptake inhibitor
Source: References 3-5
Nonhormonal treatments
SSRIs. Selective serotonin reuptake inhibitors act by blocking serotonin reuptake in the synaptic cleft. Soon after the first SSRIs were approved in 1988, reports appeared of SSRIs interfering with sexual functioning.6 This side effect quickly was exploited to assist the treatment of sexual offenders.7
The mechanism of action may include:8
- direct effects, such as general inhibition of sexual activity, reduced impulsiveness, and an effect on the hypothesized “obsessive-compulsive” nature of paraphilias9
- indirect reduction of testosterone.
A growing body of literature supports SSRIs’ effectiveness in treating paraphilias and sexual offenders. Greenberg7 reviewed case studies and open drug trials of nearly 200 patients receiving fluoxetine, fluvoxamine, or sertraline. Most studies showed response rates of 50% to 90%.10 Positive effects included decreases in:
- paraphiliac fantasies, urges, and sexual acts
- masturbation
- hypersexual activity.
Some studies reported a preferential decrease in paraphiliac interests with an increase in conventional sexual interests, although this may be related to placebo or halo effects—patients may have reported an increase in conventional interests because they noticed a decrease in paraphiliac interests. Negative side effects included decreased sexual desires, delayed ejaculation, decreased libido, and anorgasmia.
Adi et al11 completed a more rigorous literature evaluation that included 9 studies with a total of 225 patients receiving fluoxetine, fluvoxamine, sertraline, or paroxetine. Eight studies showed benefits; however, Adi noted that this preliminary evidence was “far from conclusive.”
SSRIs generally are well tolerated and may be more appealing to patients than the “chemical castration” of hormonal treatments. Dosing is similar to that used in depression or obsessive-compulsive disorder. Although most patients notice beneficial effects in 2 to 4 weeks, some notice the effect nearly immediately.
Naltrexone. An opioid antagonist thought to affect the CNS processes of pleasure and pain, naltrexone has been used to treat alcohol dependence and pathologic gambling. A few case studies12-14 and 1 study of 21 adolescent sex offenders15 have shown benefits in treating sexual offenders or paraphiliacs. Benefits were seen at 50 mg/d, with suggested dosing of 100 to 200 mg/d. Because data are very limited, consider naltrexone only on an individual basis or as a possible adjunctive treatment.
Psychostimulants. Methylphenidate was added to augment SSRI treatment in a study of 26 men with paraphilias or paraphilia-related disorders.16 Results included further significant decreases in total sexual outlets (orgasms per week) and average time spent per day in paraphilia and paraphilia-related behavior. These gains appeared to be independent of the presence of attention-deficit/hyperactivity disorder.
Again, because data are very limited, consider this strategy only on an individual basis or as a possible adjunctive treatment. Because sexual offenders have high rates of substance abuse,17 consider the potential for stimulant abuse.
Hormonal treatments
Because testosterone is required for healthy bone metabolism, the antiandrogen medications used in hormonal treatment can cause osteoporosis.18,19 Therefore, long-term antiandrogen treatment should include bone scans to monitor for osteopenia and osteoporosis. Some authors have suggested that monthly doses of 25 to 50 mg of testosterone could minimize this risk.20 Bisphosphonates, vitamin D, and calcium supplements at osteoporosis treatment levels might be helpful.18 Other common side effects of antiandrogen medications are listed in Table 2.