Focus of the intervention
This intervention focuses on the psychotherapeutic treatment of adults who have been sentenced for sexual offences against children. The review evaluated the effect of short-term cognitive behavioural therapy (CBT) programmes.
This narrative is based on one review covering 14 studies. Two were CBT only, five involved CBT and relapse prevention therapy, two were relapse prevention therapy only, and five were coded as mixed or other.
The meta-analysis included nine studies and focused on the effect of psychological treatments on rearrest and reconviction. Of the 14 primary studies, nine were based on evidence from the USA and Canada, three from the UK and two from Australia and New Zealand.
Effect – how effective is it?
There is some evidence that the intervention has either increased or reduced crime, but the meta-analysis did not detect an overall statistically significant effect of psychological treatment for sex offenders on subsequent incidences of arrest or conviction.
Of the nine studies included in the meta-analysis, four reported a reduction in rearrests and/or reconviction. One found that psychological treatment of sex offenders led to an increase in rearrest and/or reconviction in the treatment group. The remaining four studies returned non-significant results.
The review found that as the quality of the study design increased, the observed treatment effect decreased.
How strong is the evidence?
Although the review was systematic, many forms of bias that could influence the study conclusions remain.
The evidence reported here is taken from a systematic review covering 14 studies, which demonstrated high quality in terms of having a transparent and well-designed search strategy, and featuring valid statistical analysis.
The review did not sufficiently assess the risk of bias in the analysis, consider the validity of the way outcomes were measured or combined, separate analysis for distinct evaluation research designs, or quantify an overall effect for unanticipated outcomes such as displacement caused by the intervention or conduct.
Of the nine studies that passed the quality criteria for inclusion in the meta-analysis, eight were coded as 'weak' and one was coded as 'good'. The authors warn the reader of the lack of methodological quality in evaluation studies in this area which could lead to potential discrepancies in terms of reported effects between low- and high-quality study designs.
Mechanism – how does it work?
CBT is a talking therapy that can help people manage their problems by changing the way they think and behave. It is based on the notion that negative thoughts and feelings can trap somebody in a destructive cycle or pattern of behaviour.
CBT aims to address problems by helping an individual to break them down into smaller parts.
Relapse prevention therapy is a specific form of CBT that aims to limit or prevent relapses by helping the person anticipate circumstances that are likely to provoke a relapse.
The review does not explain or test the mechanisms through which the psychological treatment of sex offenders is expected to reduce crime.
Moderators – in which contexts does it work best?
The review only included studies with a minimum follow-up period of three years.
The review did not examine under what conditions or for what population groups the intervention might work best.
Implementation – what can be said about implementing this initiative?
The review does not cover in any specific detail how the psychological treatment of sex offenders was implemented across the different studies.
Nine interventions were delivered in institutions and four in the community.
Economic considerations – how much might it cost?
The review did not mention the costs or benefits of psychological treatment of sexual offenders. No formal economic analysis was provided.
- The review authors emphasise the lack of quality research studies in this area. They highlight the ‘large discrepancy’ between a substantial number of publications that are available and the ‘very small’ number of studies that are deemed to be of acceptable quality.
- Low-quality studies were found to show greater treatment effects. Further high-quality studies are needed to provide more robust findings.
There is some evidence that the psychological treatment of adults who have committed sex offences against children has either increased or reduced crime, but overall it has not had a statistically significant effect on crime.
The review found that as the quality of the studies increased, the treatment effect decreased.
A number of potential biases that could influence the study outcomes were not addressed in the review and therefore findings should be interpreted with extreme caution.
Furthermore, higher quality research is needed to better determine the effectiveness of these forms of psychological treatment for this specific offender group.
Additional evidence is also required to identify the mechanisms through which psychological treatment of sex offenders might reduce crime and any moderating conditions or population groups that might influence treatment effectiveness.
Further evidence is likewise needed to examine the implementation issues surrounding psychological treatment and any economic impact.
Grønnerød, C., Grønnerød, J. S. & Grøndahl, P. (2015) Psychological Treatment of Sexual Offenders Against Children: A Meta-Analytic Review of Treatment Outcome Studies, Trauma, Violence & Abuse Vol.16(3), 280-290
Summary prepared by
This narrative was prepared by the College of Policing and was co-funded by the College of Policing and the Economic and Social Research Council (ESRC). ESRC grant title: 'University Consortium for Evidence-Based Crime Reduction'. Grant reference: ES/L007223/1.