Psychological interventions for sex offenders or those who have sexually offended or are at risk of offending

Sexual offending is both a social and a public health issue. Victim surveys show that sexual abuse is common and that much of it is never brought to the attention of criminal justice systems.

Psychological interventions are generally based on behavioural or psychodynamic theories. Interventions might be designed to change an offender's thoughts, feelings or views on relationships, with the ultimate aim of changing their behaviour.

A Cochrane review published 10 years ago considered the evidence for psychological treatments for sexual offenders and found insufficient data to reach any conclusions (Kenworthy 2003). Our current review is based on a new protocol and a literature search conducted in September 2010.

We examined the evidence for the effectiveness of psychological interventions for sexual offenders or those considered likely to offend. We excluded interventions for sex offenders with learning disability as this is the subject of a separate Cochrane review (Ashman 2008).

We identified 10 relevant studies involving data from 944 adults, all male. Few of these studies provided information about the primary outcome of this review, which was reoffending. This was usually because studies did not collect data for a sufficiently long period outside prison or the treatment setting. Many studies relied on other outcome measures (for example, anger or social skills) chosen by investigators in the hope that they were linked in some way with future offending, although it cannot be stated with certainty that such connections reliably predict reoffending.

Five of the trials we found involved 664 men and used primarily cognitive behavioural interventions (CBT). In the largest study, which had the most complex and intense 'package' of treatment both within and outside of prison, there was no difference between the group who had received CBT and those who had not in terms of the risk of reoffending as measured by reconviction for sexual offences.

One study, involving 231 men, compared psychodynamic intervention with standard care, which was probation, and suggested that probation was mildly superior in terms of reducing reoffending.

Behavioural programmes were looked at in four trials involving 70 men. For two studies, not enough data were reported to assess the effectiveness of treatment. For the remaining two, encouraging results with regards to reconvictions and self-reported urges have to be treated with caution as the studies are relatively old, meaning that many participants would not now seek or be offered treatment, as some of the targeted behaviours have been decriminalised.

Data for adverse events, 'sexually anomalous urges' and for secondary outcomes thought to be 'dynamic' risk factors for reoffending, including anger and cognitive distortions, were limited.

We concluded that further randomised controlled trials are urgently needed in this area, so that society is not lured into a false sense of security in the belief that once the individual has been treated, then their risk of reoffending is reduced. Currently, the evidence does not support this belief.

Authors' conclusions: 

The inescapable conclusion of this review is the need for further randomised controlled trials. While we recognise that randomisation is considered by some to be unethical or politically unacceptable (both of which are based on the faulty premise that the experimental treatment is superior to the control – this being the point of the trial to begin with), without such evidence, the area will fail to progress. Not only could this result in the continued use of ineffective (and potentially harmful) interventions, but it also means that society is lured into a false sense of security in the belief that once the individual has been treated, their risk of reoffending is reduced. Current available evidence does not support this belief. Future trials should concentrate on minimising risk of bias, maximising quality of reporting and including follow-up for a minimum of five years 'at risk' in the community.

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Background: 

Sexual offending is a legal construct that overlaps, but is not entirely congruent with, clinical constructs of disorders of sexual preference. Sexual offending is both a social and a public health issue. Victim surveys illustrate high incidence and prevalence levels, and it is commonly accepted that there is considerable hidden sexual victimisation. There are significant levels of psychiatric morbidity in survivors of sexual offences.

Psychological interventions are generally based on behavioural or psychodynamic theories.

Behavioural interventions fall into two main groups: those based on traditional classical conditioning and/or operant learning theory and those based on cognitive behavioural approaches. Approaches may overlap. Interventions associated with traditional classical and operant learning theory are referred to as behaviour modification or behaviour therapy, and focus explicitly on changing behaviour by administering a stimulus and measuring its effect on overt behaviour. Within sex offender treatment, examples include aversion therapy, covert sensitisation or olfactory conditioning. Cognitive behavioural therapies are intended to change internal processes - thoughts, beliefs, emotions, physiological arousal - alongside changing overt behaviour, such as social skills or coping behaviours. They may involve establishing links between offenders' thoughts, feelings and actions about offending behaviour; correction of offenders' misperceptions, irrational beliefs and reasoning biases associated with their offending; teaching offenders to monitor their own thoughts, feelings and behaviours associated with offending; and promoting alternative ways of coping with deviant sexual thoughts and desires.

Psychodynamic interventions share a common root in psychoanalytic theory. This posits that sexual offending arises through an imbalance of the three components of mind: the id, the ego and the superego, with sexual offenders having temperamental imbalance of a powerful id (increased sexual impulses and libido) and a weak superego (a low level of moral probation), which are also impacted by early environment.

This updates a previous Cochrane review but is based on a new protocol.

Objectives: 

To assess the effects of psychological interventions on those who have sexually offended or are at risk of offending.

Search strategy: 

In September 2010 we searched: CENTRAL, MEDLINE, Allied and Complementary Medicine (AMED), Applied Social Sciences Index and Abstracts (ASSIA), Biosis Previews, CINAHL, COPAC, Dissertation Abstracts, EMBASE, International Bibliography of the Social Sciences (IBSS), ISI Proceedings, Science Citation Index Expanded (SCI), Social Sciences Citation Index (SSCI), National Criminal Justice Reference Service Abstracts Database, PsycINFO, OpenSIGLE, Social Care Online, Sociological Abstracts, UK Clinical Research Network Portfolio Database and ZETOC. We contacted numerous experts in the field.

Selection criteria: 

Randomised trials comparing psychological intervention with standard care or another psychological therapy given to adults treated in institutional or community settings for sexual behaviours that have resulted in conviction or caution for sexual offences, or who are seeking treatment voluntarily for behaviours classified as illegal.

Data collection and analysis: 

At least two authors, working independently, selected studies, extracted data and assessed the studies' risk of bias. We contacted study authors for additional information including details of methods and outcome data.

Main results: 

We included ten studies involving data from 944 adults, all male.

Five trials involved primarily cognitive behavioural interventions (CBT) (n = 664). Of these, four compared CBT with no treatment or wait list control, and one compared CBT with standard care. Only one study collected data on the primary outcome. The largest study (n = 484) involved the most complex intervention versus no treatment. Long-term outcome data are reported for groups in which the mean years 'at risk' in the community are similar (8.3 years for treatment (n = 259) compared to 8.4 in the control group (n = 225)). There was no difference between these groups in terms of the risk of reoffending as measured by reconviction for sexual offences (risk ratio (RR) 1.10; 95% CI 0.78 to 1.56).

Four trials (n = 70) compared one behavioural programme with an alternative behavioural programme or with wait list control. No meta-analysis was possible for this comparison. For two studies (both cross-over, n = 29) no disaggregated data were available. The remaining two behavioural studies compared imaginal desensitisation with either covert sensitisation or as part of adjunctive drug therapy (n = 20 and 21, respectively). In these two studies, results for the primary outcome (being 'charged with anomalous behaviour') were encouraging, with only one new charge for the treated groups over one year in the former study, and in the latter study, only one new charge (in the drug-only group) over two years.

One study compared psychodynamic intervention with probation. Results for this study (n = 231) indicate a slight trend in favour of the control group (probation) over the intervention (group therapy) in terms of sexual offending as measured by rearrest (RR 1.87; 95% CI 0.78 to 4.47) at 10-year follow-up.

Data for adverse events, 'sexually anomalous urges' and for secondary outcomes thought to be 'dynamic' risk factors for reoffending, including anger and cognitive distortions, were limited.