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Practice Profile

Adult Sex Offender Treatment

Evidence Ratings for Outcomes:

Promising - More than one Meta-Analysis Crime & Delinquency - Multiple crime/offense types
Promising - One Meta-Analysis Crime & Delinquency - Sex-related offenses
No Effects - One Meta-Analysis Crime & Delinquency - Violent offenses

Practice Description

Practice Goals/Target Population
Given that the large majority of incarcerated adult sex offenders will someday return to the community, finding ways to treat, manage, and supervise these offenders is imperative (Schmucker and Lösel 2008). One approach is to provide treatment for sex offenders. The main goal of sex offender treatment is to reduce the risk of recidivism for this offender population. A variety of offenders fall within the sex offender category, some of whom are rapists, child molesters, incest offenders, pedophiles, and cyber offenders (Robertiello and Terry 2007).

Program Components
Sex offender treatment programs are based on a variety of methods, some of which are cognitive–behavioral methods, classical behavioral, insight oriented, hormonal medication, medical castration, therapeutic communities, faith-based treatment, and intensive supervision (Kirsch and Becker 2006).

Cognitive–Behavioral Therapy
Cognitive–behavioral therapy (CBT) is usually conducted in a group therapy setting and involves addressing the irrational thoughts and beliefs of offenders that lead them to engage in antisocial behaviors (Aos et al. 2006). CBT programs include elements that seek to help offenders correct their deviant thoughts by practicing opportunities to model and engage in prosocial and problem-thinking skills and behaviors (Aos et al. 2006).

Programs that fall into this category involve the use of insight-oriented therapy that can be done either individually or in a group setting (Aos et al. 2006). These programs usually take the form of traditional therapy practices such as talk therapy and exploring the underlying causes and thoughts related to offending behaviors. These programs and approaches can be general or sex offender specific.

Medical Treatment of Sex Offenders
There have been numerous attempts over the last few decades to use medical approaches to treat and reduce the risk of sex offenders and sex-offending behaviors. These include approaches such as surgical castration and hormonal therapy (Aos et al. 1996). Participating in surgical castration is done entirely on a volunteer basis (Lösel and Schmucker 2005). These approaches almost always combine the medical intervention with additional psychological treatment as well so that if offenders stop taking their hormones, they will still have had some type of treatment (Lösel and Schmucker 2005).

Current sex offender treatment practice typically consists of the therapist or other trained professionals attempting to get offenders to take responsibility for their actions, while also addressing and treating any underlying co-occurring disorders. The therapist works with offenders to help them recognize the wrongfulness of their actions, while also documenting and advising the courts on the level of risk each offender may be to the community.

Sex offenders’ eligibility to participate in a treatment program may depend on several factors, such as willingness to participate, risk level, seriousness of the current sex offense, or availability of treatment slots (Hanson et al. 2002). Offenders convicted of sex offenses will usually receive treatment as a condition or requirement of their sentence.

Sex offender treatment can occur in the community or while the sex offender is in a secure setting, such as a prison or mental health facility. Although some sex offender programs are mandatory, others will accept only those who volunteer for treatment. In addition, sex offenders may receive treatment geared specifically toward addressing sexually aggressive behavior, or they may receive treatment directed toward addressing general offending behavior. Violent or high-risk offenders usually receive some sort of treatment, incident specific or more broadly based (Aos et al. 2006). However, owing to the resources available in many communities, sex offender specific treatment options may not be available to those offenders, who instead receive generalized therapies. Research has been inconclusive about whether specific treatment approaches are better than generalized ones, but the meta-analysis by Lösel and Schmucker (2005) found that unspecific offender programs had no impact on rates of sexual recidivism, suggesting that general programs may not provide the necessary treatment that sex offenders need.

Key Personnel
Professionals trained in sex offender specific treatments lead therapy sessions and other intervention strategies. These individuals typically include professionals who have acquired a certain level of education (e.g., master’s degree, doctorate, M.D.), such as trained nurses, licensed social workers, and parole/probation officers. Some programs may also use clergy as an additional personnel resource.

Meta-Analysis Outcomes

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Promising - More than one Meta-Analysis Crime & Delinquency - Multiple crime/offense types
Overall, three meta-analyses found that providing treatment had significant, positive impacts on the general recidivism rates of sex offenders. Aos and colleagues (2006) looked at the results from five studies that examined the effectiveness of cognitive–behavioral therapy (CBT) for sex offenders in prison. They found that CBT programs in prison had a significant impact on sex offenders, reducing general recidivism by 14.9 percent (ES=–0.144). Across 36 studies examining various treatment approaches in prison, hospital, and outpatient settings, Lösel and Schmucker (2005) also found that treatment for sex offenders significantly reduced general recidivism, but the effect of treatment was small (odds ratio [OR]=1.43). Across 10 studies looking at sex offender treatment in institutions and community settings, Hanson and colleagues (2009) found that the general recidivism rate of the treatment group was significantly lower than the general recidivism rate of the comparison group, but the effect of treatment was small (OR=0.71).
Promising - One Meta-Analysis Crime & Delinquency - Sex-related offenses
Across 18 studies, Hanson and colleagues (2009) found that the sexual recidivism rate of the treatment group was significantly lower than the sexual recidivism rate of the comparison group (OR=0.71).
No Effects - One Meta-Analysis Crime & Delinquency - Violent offenses
Across eight studies, Hanson and colleagues (2009) found there were no significant differences between the treatment and comparison group when looking at violent recidivism rates (including sexual recidivism).
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Meta-Analysis Methodology

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Meta-Analysis Snapshot
 Literature Coverage DatesNumber of StudiesNumber of Study Participants
Meta-Analysis 11995 - 20005900
Meta-Analysis 21970 - 20046922181
Meta-Analysis 31980 - 2009236746

Meta-Analysis 1
The 2006 meta-analysis by Aos, Miller, and Drake updated and extended an earlier 2001 review by Aos and colleagues. The overall goal of the review was to provide policymakers at Washington State Institute for Public Policy with a comprehensive assessment of adult corrections programs and policies that have the ability to affect crime rates. This meta-analysis concentrated exclusively on adult corrections programs.

A comprehensive search procedure was used to identify eligible studies. Studies were eligible to be included if they 1) were published in English between 1970 and 2005, 2) were published in any format (peer-reviewed journals, government reports, or other unpublished results), 3) had a randomly assigned or well-matched comparison group, 4) had intent-to-treat groups that included both complete and program dropouts, or sufficient information was available that the combined effects could be tallied, 5) provided sufficient information to code effect sizes, and 6) had at least a 6-month follow-up period and included a measure of criminal recidivism as an outcome.

The search resulted in the inclusion of five evaluations of sex offender programs. The five studies included close to 900 participants. Two studies were published in a journal. The other studies were government reports or unpublished evaluations. No information was provided on the age, gender, or racial/ethnic breakdown of the studies’ samples, nor on the location of the programs.

The mean difference effect size was calculated for each program. Adjustments were made to the effect sizes for small sample sizes, evaluations of “non–real world” programs, and for the quality of the research design. The quality of each study was rated using the University of Maryland’s five-point scale; only studies that received a rating of 3 or higher on the scale were included in the analysis (a rating of 3 means a study used a quasi-experimental design with somewhat dissimilar treatment and comparison groups but there were reasonable controls for differences). Once effect sizes were calculated for each program effect, the individual measures were added together to produce a weighted average effect size for a program or practice area. The inverse variance weight was calculated for each program effect, and those weights were used to compute the average. The fixed-effects model was used for the analysis.

Meta-Analysis 2
Lösel and Schmucker (2005) conducted a comprehensive, review of sex offender treatment programs. Studies were included in their meta-analysis if they met the following criteria: 1) participants in each study had to have been convicted of a sex offense or must have been committing acts of illegal sexual behavior that would result in a conviction if prosecuted, 2) the intervention program had to be aimed at reducing recidivism, 3) interventions had to include therapeutic measures and did not need to be specifically designed for sex offenders, 4) studies could not have offered only purely deterrent or purely punishing treatment programs, 5) recidivism had to be included as a dependent variable, 6) each study had to report the same recidivism outcomes for the comparison group who were not receiving the same treatment, 7) the studies had to have a sample size of at least 10 with a minimum of 5 sex offenders placed in each group, 8) data had to be reported that allowed for the calculation of effect sizes, 9) studies had to be either in Dutch, English, French, German, or Swedish, and, finally, 10) studies were not limited by report date and all studies were included until 2003.

The authors conducted their literatures search by compiling references from previous meta-analysis reviews and individual studies, using electronic databases (such as PsycINFO and MEDLINE), hand-searching journals directly related to the topic, contacting researchers in the sex-offender treatment field for additional suggestions or for unpublished reports, and using a basic Internet search of relevant institutions and corrections departments for pertinent materials. This method resulted in the identification of 2,039 possible citations. Further analysis resulted in a final 66 reports meeting the authors criteria. Several of the reports contained more than one eligible study, so the authors used each eligible individual study as a separate unit of analysis. Other studies presented results of different subgroups, such as type of offense. The authors chose to use those subgroups as individual units of analysis as well. This resulted in 80 eligible comparisons from a total of 69 studies.

An adapted version of the Maryland Scale of Scientific Rigor was used to evaluate overall methodological quality of the 69 individual studies. Only studies that received a rating of 2 or higher on the scale were included in the analysis. A large majority of the studies (69.5 percent) included in the meta-analysis came from North America (Canada and the United States). About half of the studies were published in peer-reviewed journals, and the other half were book chapters or unpublished studies. Treatment material differed greatly, with half using cognitive–behavioral therapy (CBT) programs and 14 comparisons using physical therapy programs (8 of these were surgical castration). Sample size varied from 15 to 2,557, with about one third of comparisons containing fewer than 50 offenders. Almost all of the studies had a follow-up period longer than 5 years.
Participants in the studies were mostly adults (56.3 percent adult versus 17.5 percent juvenile sex offenders, while 10 percent included mixed age groups, and 25 percent had unclear age groups). Participation in the treatment program was usually voluntary (46.3 percent compared to 20 percent nonvoluntary, while 10 percent had mixed participation, and 23.8 percent had unclear participation). Child molestation (73.7 percent), rape (55.0 percent), and incest (47.5 percent) were the most common offense types (individual comparisons may cover multiple categories of offenses).

The meta-analysis used odds ratios (OR) to measure effect sizes. For studies that did not report statistics that could be easily transformed into OR, the authors used standard procedures to calculate Cohen’s d and then used this statistics to calculate OR.

Meta-Analysis 3
Hanson and colleagues (2009) conducted a meta-analysis on whether principles associated with effective interventions for general offenders (risk–need–responsivity) would also apply to psychological treatments of sexual offenders. The basis for this research was formed from earlier data that shows that the most effective types of programs for general offenders are those that follow the risk–need–responsivity (RNR) model. Treatments using the RNR methodology follow 3 main tenants: 1) treatment is more likely to be effective for offenders who are at a moderate or higher risk of offending, 2) target the characteristics that are most closely related to the offending behaviors, also known as criminogenic needs, and 3) match the treatment with the offenders’ learning styles and abilities.

The authors selected studies by conducting searches of databases, such as PsychINFO, Web of Science, Digital Dissertations, and the National Criminal Justice Reference Service. They found additional materials using the reference lists of collected articles, program materials from conferences, and a general review of articles on the topic. To be included in the meta-analysis, studies had to examine treatment effectiveness by comparing recidivism rates using a sex-offender population with a matching comparison group of sex offenders. The authors defined sex offenders as “offenders with sexually motivated offenses against an identifiable victim” (Hanson et al. 2009, 868). Participants in the control/comparison group could have received an alternate treatment, less treatment, or no treatment. For the studies to meet the need principle of the RNR model, at least 51 percent of the treatment had to target criminogenic needs, such as antisocial lifestyle, impulsivity, or negative peer associations. Services in the treatment program met the responsivity aspect of RNR when the treatment was provided in such a way as to match the needs and learning style of the client.

The number of eligible studies was narrowed down using the Collaborative Outcome Data Committee (CODC) guidelines, which help in determining the extent to which a study’s features indicate possible bias when estimating treatment effect. Only studies categorized as weak, good, and strong were included. This resulted in a total of 23 studies included in the analysis. Of these, 14 were published and 9 were unpublished. Most of the studies (74 percent) were from North America (Canada and the United States). Of the 14 studies, 10 included adult males while 4 studies focused exclusively on juveniles. In addition, 3 studies indicated the inclusion of some female offenders in the sample). The sample sizes ranged from 16 to 2,557. In 10 of the studies the treatment programs were offered in institutions, and in 11 studies they were offered in the community (in two studies the treatment was offered in both settings).

Statistics were calculated using both a fixed effect and random effect models and by calculating odds ratio.
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There is no cost information available for this practice.
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Other Information

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A few meta-analyses included additional tests—called moderator analyses—to see whether any factors strengthened the likelihood that sex offender treatment improved outcomes. Medical Treatment Approaches There are several limitations to certain types of treatment approaches for sex offenders, specifically medical treatment options. For example, participants who undergo chemical castration also experience severe negative side effects attributable to treatment that results in higher noncompliance and dropout rates (Lösel and Schmucker 2005). In addition, when examining the different types of sex offender treatments using a moderator analysis, Lösel and Schmucker (2005) found that the average effects of physical treatments were much larger than psychosocial programs, where both surgical castration and hormonal medications show strong positive outcomes. However, the studies suffer from several limitations. For instance, sex offenders who volunteer to undergo surgical castration are usually a highly motivated and highly selected treatment group, which introduces a severe selection bias into the study. The sample sizes of the studies also tend to be very small, and the members of the control groups are not always very comparable with treatment group members. This type of treatment approach also comes with a lot of ethical and legal questions, which in turn make it a seldom used practice (Lösel and Schmucker 2005). Psychosocial Approaches Aos and colleagues (2006) found that cognitive–behavioral therapy for sex offenders, delivered in a prison setting, significantly reduced recidivism by 14.9 percent, but that psychotherapy/ counseling programs (which involve insight-oriented individual or group therapy) and behavioral treatment programs (that focus on deviant arousal using biofeedback and other conditioning) for offenders did not significantly reduce rates of recidivism for sex offenders. Other Important Factors The moderator analyses conducted by Lösel and Schmucker (2005) found that when sex offenders voluntarily participated in treatment, their average effect size was significantly positive, meaning that they were less likely to reoffend compared to treatment mandated offenders. They also found that whether or not treatment was terminated regularly or prematurely affected rates of sexual recidivism, where early dropouts did significantly worse (doubled the odds of relapse). They also found that programs that were not sex-offender specific made no impact on sexual recidivism for offenders. Location of treatment was another important factor, with ambulatory programs having larger effects than institutional set programs.
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Evidence-Base (Meta-Analyses Reviewed)

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These sources were used in the development of the practice profile:

Meta-Analysis 1
Aos, Steve, Marna Miller, and Elizabeth Drake. 2006. Evidence-Based Adult Corrections Programs: What Works and What Does Not. Olympia, Wash.: Washington State Institute for Public Policy.

Meta-Analysis 2
Lösel, Friedrich, and Martin Schmucker. 2005. “The Effectiveness of Treatment for Sexual Offenders: A Comprehensive Meta-Analysis.” Journal of Experimental Criminology 1:117–46.

Meta-Analysis 3
Hanson, R. Karl, Guy Bourgon, Leslie Helmus, and Shannon Hodgson. 2009. “The Principles of Effective Correctional Treatment Also Applied to Sexual Offenders: A Meta-Analysis.” Criminal Justice Behavior 36:865–91.
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Additional References

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These sources were used in the development of the practice profile:

Day, Andrew, Christina Kozar, and Linda Davey. 2013. “Treatment Approaches and Offending Behavior Programs: Some Critical Issues.” Aggression and Violent Behavior 18(6):630–35.

Hanson, R. Karl, Arthur Gordon, Andrew J.R. Harris, Janice K. Marques, William Murphy, Vernon L. Quinsey, and Michael C. Ceto. 2002. “First Report of the Collaborative Outcome Data Project on the Effectiveness of Psychological Treatment for Sex Offenders.” Sexual Abuse: A Journal of Research and Treatment 14(2):169–94.

Kirsch, Laura G., and Judith V. Becker. 2006. “Sexual Offending: Theory of Problem, Theory of Change, and Implications for Treatment Effectiveness”. Aggression and Violent Behavior 11:208–24.

Robertiello, Gina, and Karen J. Terry. 2007. “Can We Profile Sex Offenders? A Review of Sex Offender Typologies.” Aggression and Violent Behavior 12:508–18.

Schmucker, Martin, and Friedrich Lösel. 2008. “Does Sexual Offender Treatment Work? A Systematic Review of Outcome Evaluations.” Psicothema 20(1):10–19.
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Related Programs

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Following are programs that are related to this practice:

Electronic Monitoring (Florida) Promising - One study
Uses systems based on radio frequency or global positioning system (GPS) technology to monitor offenders’ locations and movements in community-based settings. The program is rated Promising. Compared with the control group on other forms of community supervision, the technology reduced the risk of failure to comply.

Minnesota Prison-Based Sex Offender Treatment Program Promising - One study
The program offers treatment, therapy, and transitional services to convicted male sex offenders in prison. The program is rated Promising. Participants recidivated less and more slowly than untreated inmates. Treatment also impacted recidivism for violent and general offenses; but was not found to be more, or less, effective for certain types of sex offenders.

New Jersey Adult Diagnostic Treatment Center (ADTC) Promising - One study
The program provides both cognitive–behavioral treatment and relapse prevention to repetitive, compulsive sex offenders. Cognitive–behavioral treatments focus on reconstructing offender’s cognitive distortions; relapse prevention focuses on pattern recognition and breaking the cycle of recommitting sex crimes. The program is rated Promising. The intervention participants were 2.4 times less likely to recidivate, compared with the general prison-population comparison group.

Regional Treatment Centre Sex Offender Treatment Program (Canada) No Effects - One study
This inpatient program provides group and individual therapy to those who have committed sexual offenses and have recently been released from prison in Ontario, Canada. The program is rated No Effects. There was no significant difference in sexual recidivism rates between the treatment group and the comparison group.
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Practice Snapshot

Age: 18+

Gender: Both

Targeted Population: High Risk Offenders, Prisoners, Serious/Violent Offender, Sex Offenders

Settings: Correctional, Inpatient/Outpatient, Other Community Setting

Practice Type: Cognitive Behavioral Treatment, Group Therapy, Individual Therapy, Specific deterrence, Violence Prevention

Unit of Analysis: Persons