Psychological interventions for those who have sexually offended or are at risk of offending
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To evaluate the effects of psychological interventions on those who have sexually offended or are at risk of offending.
Background
Description of the condition
Sexual offending is a legal construct which overlaps, but is not entirely congruent with, the clinical constructs of disorders of sexual preference as described in the ICD‐10 Classification of Mental and Behavioural Disorders (WHO 1992) or paraphilias as described in the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (APA 1994). Most but not all sexual offences are disorders of sexual preference or paraphilias and most but not all disorders of sexual preference or paraphilias are sexual offences. For instance, clinically defined sexual behaviours such a paedophilia, voyeurism, frotteurism, exhibitionism, zoophilia and necrophilia also meet the rubric for sexual offences but, for instance, fetishism and transvestic fetishism do not. Crimes such as rape and incest with adult victims are not of themselves classified as disorders of sexual preference or paraphilias.
Sexual offending is both a social problem and a public health issue (Laws 1999). People who have committed a sexual offence represent nearly one quarter of the total population in state prisons in the USA (McGrath 2003). Victim surveys illustrate high incidence and prevalence levels and it is commonly accepted that there is a high proportion of hidden sexual victimization (Chapman 2004, Edwards 2003, Hood 2002). A number of surveys have reported high levels of psychiatric morbidity in survivors of sexual offences (McCauley 1997, Mchichi 2004, Molnar 2001, Swanston 2003, Chapman 2004, Hill 2000).
Sexual offending has become a major challenge for social policy. The electorate and the media expect policy makers to be accountable for the effects of their responses to sexual offending. In the UK, provisions in the Sexual Offences Act 2003 include substantial increases in sentence length for many sexual offences and increased state control, in terms of notification requirements and supervision, for up to ten years after a sentence has been spent (Great Britain 2003). In the USA, such concerns led to Megan's Law in 1996, which allows private and personal information on those registered as sex offenders against children to be made available to the community (About Megan's Law 2007). Exaggerating the danger that sexual offenders pose is problematic and may increase public fear, stigmatise and hinder rehabilitation of offenders who have changed their lifestyles, while wasting valuable resources on unnecessary surveillance (Soothill 2000).
Description of the intervention
This review focuses solely on psychological interventions for those who have sexually offended or are at risk of offending and does not encompass anti‐libidinal interventions (“chemical” or surgical castration, stereotaxic neurosurgery and psychotropic medications that have anti‐libidinal side effect) which is the subject of a separate Cochrane review, currently under development (Khan 2008). The crucial difference between psychological and anti‐libidinal interventions for sex offenders is that the goal of anti‐libidinal interventions is the significant decrease or elimination of sexual desire and performance whereas psychological interventions leave performance intact but seek to redirect the offender’s sexual expression to socially and legally acceptable outlets.
Psychosocial interventions are broadly divided into two categories: behavioural (including cognitive‐behavioural) and psychodynamic.
Behavioural interventions
Behavioural interventions fall into two main groups, those based on traditional classic and operant learning theory and on cognitive behavioural approaches In reality, the differences between these two approaches may be blurred with traditional approaches admitting some cognitive components and cognitive‐behavioural programmes admitting some classical and/or operant components. Bearing in mind the permeability of the boundaries between these two approaches in practice, they may be described as follows: styles of intervention associated with traditional classical and operant learning theory are generally referred to as behaviour modification or behaviour therapy. The hallmark of these interventions is an explicit focus on changes in behaviour by administering a stimulus and measuring its effect upon overt behaviour. Within sex offender treatment, examples include aversion therapy (exposure to deviant material followed by aversive stimulus), covert sensitisation (imagine deviant sexual experience until arousal and then imagine powerful negative experience), olfactory conditioning (an unpleasant odour is paired with images or descriptions of sexual offences) and masturbation satiation / orgasmic reconditioning (masturbation to an appropriate sexual fantasy).
Cognitive‐behavioural interventions are intended to change internal processes ‐ thoughts, beliefs, emotions, physiological arousal ‐ alongside changing overt behaviour, such as social skills or coping behaviours. They involve all or most of the following: 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. Cognitive behavioural interventions are the basis of sex offender treatment in prison systems and community programmes in England, Canada, New Zealand, and the USA.
Psychodynamic interventions
Psychodynamic interventions encompass a range of psychological interventions that share a common root in psychoanalytic theory. At the heart of psychoanalytical theory is the development and balance between the three hypothesised components of mind, the id, the ego and the superego. The id is the seat of all unconscious drives including the sexual drive; the ego is the seat of consciousness and also unconscious defence mechanisms; the superego internalises demands and prohibitions from parental objects of childhood (Kernberg 2000). Family environment impacts on achieving this development and balance and the negative consequences of failure to achieve this balance include a whole range of psychopathology including sexual deviancy.
Psychodynamic interventions range from strictly Freudian psychoanalysis as carried out by a licensed (Freudian) psychoanalyst to licensed practitioners of the neo‐ or post Freudian schools such as Jung, Adler, Klein etc. They also include interventions carried out by licensed psychotherapists whose psychotherapy is based on broad psychodynamic theory (Cordess 1996).
The terms 'psychoanalysis' and 'psychodynamic psychotherapy' are sometimes used interchangeably. For the purposes of this review, psychoanalysis is defined as regular individual sessions with a trained psychoanalyst , planned to last a minimum of 30 minutes and taking place three to five times a week. The course of psychoanalysis should continue for at least one year and analysts are required to adhere to a strict definition of psychoanalytic technique.
In psychoanalysis, therapists working within this population seek to work at the 'infantile sexual relations level' as conceptualised within psychoanalytic theory (Cordess 1996). Psychodynamic psychotherapy is defined as regular individual therapy sessions with a trained psychotherapist, or a therapist under supervision. Therapy sessions are to be based on a psychodynamic or psychoanalytic model. Sessions can rely on a variety of strategies, including explorative insight‐oriented, supportive or directive activity, applied flexibly. Psychodynamic psychotherapists can use a less strict technique than in psychoanalysis but to be considered well‐defined psychodynamic psychotherapy, therapists are required to deal with 'transference' issues (defined as the unconscious transfer of feelings to a person which do not befit that person and which actually apply to another (Greenson 1967)). Psychodynamic approaches are common within the UK for this population (Grubin 2002)
How the intervention might work
Behavioural interventions for sex offenders are based on learning theory and inappropriate sexual behaviour is behaviour that has been learned. These behaviours should be capable of being extinguished by standard conditioning methods using negative or positive reinforcers. In addition, it is theorised that appropriate sexual behaviour can be learned. Cognitive behavioural interventions are based on the principle that thinking controls overt action and that sexual offenders can learn new ways of thinking and new skills that can, in turn, control behaviour (Cordess 1996 ).
From the perspective of psychodynamic theory, sexual offending may be attributable to very weak superegos and very strong ids. Alternatively, according to this theory, the mother‐son relationship may be at fault with the mother sending ambiguous messages to the son; such a situation may also encourage “covert incest” where the son adopts all the roles of the spouse apart from sexual relations. It is thought that these hypothesised casual factors might be treatable by psychodynamic interventions in their various forms (Cordess 1996).
Why it is important to do this review
As has been described above, both the prevalence of sexual offending and the association between victimisation and subsequent mental health problems means that these offences make a significant contribution to mental health morbidity. There is strong social and political pressure to do something about this problem and both to help the victims and prevent sexual recidivism. At the same time there is a clear need for interventions to be evidence based and that we can be confident that offenders who have completed such programmes really are at a reduced risk of re‐offending.
Researchers have responded to needs identified above over the past decade. An early Cochrane review (White 1998) looked at all types of interventions for sexual offending; it was partially updated in 2003 in a review which considered only psychological interventions (Kenworthy 2003). The older review identified only two studies relevant to this area (total n= 286) and reported no clear effects for either CBT‐based ‘relapse prevention programme’ (Marques 1993) or group psychotherapy (Romero 1983).
In the 2003 update, Kenworthy et al reported that since the publication of White 1998'some evidence indicating positive effects of psychological interventions... [had] begun to emerge (Beech 1998) and the theoretical sophistication with which the phenomena are explained... [had] advanced (Ward 2002).’ They also reported findings by Alexander et al (Alexander 1999) wherein ‘analysis of treatment outcomes for almost 11,000 sexual offenders from 79 sex offender treatment studies found that people who participated in relapse prevention programmes had a 7.2% re‐arrest rate compared with 13.2% for all treated offenders, and 17.6% for untreated offenders’. They further noted that ‘Small treatment effects, measured by reconviction, have been found in low and medium risk offenders (Friendship 2003b) although many years of follow up are necessary before any intervention is deemed to be fully evaluated (Wood 2000). As the number of offenders who have multiple victims is considerable, a small treatment effect is important due to the significant reduction in harm to society (Hanson 2000). Proponents of treatment suggest greater effects might be present yet only detectable using more sensitive psychometric measurement instead of reconviction data (Friendship 2003a)’ (Kenworthy 2003).
In Kenworthy 2003's Cochrane review, data from nine studies with over 500 male participants were reported (Anderson‐Varney 1991, Hopkins 1991, Marques 1993, McAnaney 1981, McConaghy 1985, McConaghy 1988, Romero 1983, Rooth 1974, Ryan 1997); however, conclusions for clinicians were not robust in any direction ‐ “limited data make recommendations difficult” (Kenworthy 2003). The review made an urgent call for high quality studies with longterm followup, reported according to CONSORT standards (Moher 2001), whilst appreciating the difficulties such research entailed.
Subsequently, a Campbell systematic review by Lösel and Schmucker (Lösel 2005) which, like that by White et al, considered all treatment options for sex offenders but included studies of a larger range of designs. This review reported impressive treatment effective sizes in terms of preventing sexual recidivism for the anti‐libidinal interventions of surgical castration (effect size 15.34) and “chemical castration” (effect size 3.08) but the comparable treatment effect sizes for classic behaviour therapy and cognitive behavioural interventions, though still significant, were less impressive, 2.19 and 1.45 respectively. However, the research base for anti‐libidinal interventions is problematic being based on volunteers compared with controls who were either unsuitable for or declined the intervention. While these anti‐libidinal interventions remain voluntary their uptake is likely to be limited. Psychological interventions for sexual offending remain the interventions that most offenders will be motivated towards and likely to participate in, and an up‐to‐date review of their effects therefore remains important.
The previous version of the Cochrane systematic review by Kenworthy et al included studies identified via literature searches up to and including 2002 (Kenworthy 2003). The current authors conclude that it is now timely to update this review (including the original protocol) and to reassess the evidence supporting psychological intervention for these offenders.
Objectives
To evaluate the effects of psychological interventions on those who have sexually offended or are at risk of offending.
Methods
Criteria for considering studies for this review
Types of studies
All relevant randomised control trials with or without blinding will be included. Quasi‐randomised trials, such as those where allocation was undertaken on surname, will be excluded.
Types of participants
Adults aged 18 years old and over treated in institutional (prison or psychiatric facility) or community settings for sexual behaviours that have resulted in conviction or caution for sexual offences, offences with a sexual element or violent behaviours with a sexual element, or seeking treatment voluntarily for behaviours which would be classified as illegal. We will also include violent behaviours with a sexual element e.g. a sexual offence with murder where murder is the index offence. We will include studies where behaviours which would be classified as illegal, where there has been no criminal case reported but where the perpetrator sought treatment or admitted to the behaviours in self report.
Defining what constitutes a sexual offence in the context of the international literature can be problematic as definitions of criminally sexual behaviour differ between jurisdiction, cultures and over time. Rather than focus on just one jurisdiction, such as UK law, we will include trials of interventions where the participants have committed a sexual offence which would be accepted by most jurisdictions as crimes. These core sexual offences can be described as penetrative or non penetrative sexual acts carried out by adults on non consenting adult victims and penetrative or non penetrative sexual acts carried out by adults on consenting or non consenting minors. We would also include penetrative or non penetrative sexual acts carried out by adults on other adults where the victim was unable to give informed consent due to their physical and/or mental disability.
We will exclude studies of interventions for sex offenders where there is no clear international consensus as to whether the sexual behaviour is a crime or not. Examples include consenting same sex acts between adults, consenting sadomasochistic acts and transvestitism. We will also exclude interventions for sex offenders with learning disability as this is the subject of a separate Cochrane review (Ashman 2008).
Types of interventions
All psychological interventions compared with standard care or another psychological therapy.
Types of outcome measures
Primary outcomes
Recidivism as measured by reconviction or caution.
Recidivism as measured by self report.
Secondary outcomes
Suicide or suicide attempts.
Sudden and unexpected death by other causes.
Leaving treatment early.
Lost to follow up.
Outcomes will be divided into immediate (within 6 months), short term (>6 months ‐ 24 months) and medium term (>24 months ‐ 5 years) and long term (beyond 5 years) during the period at risk e.g. post release from prison or discharge from hospital facility. If the participants were receiving treatment in the community then the period at risk commences from the end of treatment.
Search methods for identification of studies
Electronic searches
The following databases will be searched:
Cochrane Central Register of Controlled Trials
MEDLINE
AMED‐ Allied and Complementary Medicine
ASSIA ‐ Applied Social Sciences Index and Abstracts
BHI ‐ British Humanities Index
Biosis Previews ‐ Biological Abstracts
CINAHL
COPAC ‐ Consortium of University Research Libraries joint catalogue
Dissertation Abstracts
EMBASE
IBSS ‐ International Bibliography of the Social Sciences
ISI Proceedings
ISI‐SCI ‐ Science Citation Index Expanded
ISI‐SSCI ‐ Social Sciences Citation Index
National Criminal Justice Reference Service Abstracts Database
Open SIGLE
PsycINFO;
Social Care Online
Sociological Abstracts
UK Clinical Research Network Portfolio Database
ZETOC;
The following strategy will be used to search MEDLINE and modified, where necessary, for the other databases:
1 exp Sex Offenses/
2 exp Paraphilias/
3 exp Sexual Behavior/
4 exp Child Abuse, Sexual/
5 exp "Fetishism (Psychiatric)"/
6 exp Exhibitionism/
7 exp Voyeurism/
8 exp Pedophilia/
9 exp Sadism/
10 exp Masochism/
11 exp Incest/
12 exp Rape/
13 (sex$ adj2 devia$).tw.
14 (public adj2 masturbat$).tw.
15 (child$ adj2 molest$).tw.
16 (child$ adj2 (sex$ or abuse$)).tw.
17 (sex$ adj2 (murder$ or tortur$ or abus$ or fondl$)).tw.
18 (indecen$ adj2 behav$).tw.
19 (child$ adj2 porn$).tw.
20 (lewd$ adj2 (behav$ or act)).tw.
21 bondag$.tw.
22 frotteur$.tw.
23 necrophi$.tw.
24 bugger$.tw.
25 molest$.tw.
26 pederast$.tw.
27 paedoph$.tw.
28 pedoph$.tw.
29 scatologia.tw.
30 necrophilia.tw.
31 zoophilia.tw.
32 coprophilia.tw.
33 urophilia.tw.
34 partialism.tw.
35 klismaphilia.tw.
36 bestiality.tw.
37 sodom$.tw.
38 molest$.tw.
39 paraphil$.tw.
40 voyeur$.tw.
41 or/1‐40
Randomised control filters will also be used where appropriate. No language or date restrictions will be applied. The electronic searches will be constructed taking into account changing terminology and perception of sex offences. We recognise that several of these terms would now be regarded as unacceptable and/or misleading as terms signifying sexual offending.
Searching other resources
Hand searching
Reference lists of included studies will be searched for additional relevant trials along with the reference lists of reviews.
Requests for additional data
The first author of each included study and known experts in the field will be contacted for information regarding unpublished data and/or ongoing studies.
Data collection and analysis
Selection of studies
Titles and abstracts of studies identified through searches will be independently assessed by two review authors (MF and NH). Full copies of those which appear to meet the inclusion criteria will then be assessed independently by the two authorss. We will resolve uncertainties concerning the appropriateness of studies for inclusion in the review through consultation with a third reviewer (CB). Authors will not be blinded to the name(s) of the study author(s), their institution(s) or publication sources at any stage of the review.
Data extraction and management
Data will be extracted independently by two authors (MF & NH) using a piloted data extraction form. Information on study design and implementation, setting, sample characteristics, intervention characteristics and outcomes will be extracted from all included studies.
Data will be entered into RevMan 5. Where data are not available in the published trial reports, we will contact the authors and ask them to supply the missing information.
Assessment of risk of bias in included studies
For each included study, two authors (NS and HJ) will independently complete the Cochrane Collaboration’s tool for assessing risk of bias. This will assess the degree to which:
· the allocation sequence was adequately generated (‘sequence generation’)
· the allocation was adequately concealed (‘allocation concealment’)
· knowledge of the allocated interventions was adequately prevented during the study (‘blinding’)
· incomplete outcome data were adequately addressed
· reports of the study were free of suggestion of selective outcome reporting
· the study was apparently free of other problems that could put it at high risk of bias
Measures of treatment effect
All outcomes are dichotomous and we will use the risk ratio (RR) with a 95% confidence interval to summarize results within each study. Comparisons will be made at specific follow‐up periods:
· within the first six months
· between six and twenty four months
· between 24 and five years
· Beyond five years
Unit of analysis issues
Cluster randomized trials are unlikely in this area and cross‐over trials are also unlikely in psychological interventions where “wash out” is not possible. Multiple observations are a possible issue hence the decision to define specific follow‐up periods.
Dealing with missing data
We will assess missing data and dropouts for each included study and will report the number of participants who are included in the final analysis as a proportion of all randomized participants in each study. We will provide reasons for missing data in the narrative summary.
Assessment of heterogeneity
We will assess the extent of between‐trial differences and the consistency of results of any meta‐analysis in three ways:
· by visual inspection of the forest plots,
· by performing the Chi squared test of heterogeneity (where a significance level less than 0.10 will be interpreted as evidence of heterogeneity)
· by examining the I2 statistic (Higgins 2008; section 9.5.2)
The I2 statistic describes approximately the proportion of variation in point estimates due to heterogeneity rather than sampling error. We will consider I2 values less than 30% as indicating low heterogeneity, and values greater than 70% as indicating high heterogeneity. Because heterogeneity may well prove to be a significant problem we will carry out each analysis twice using fixed and random effects models.
Assessment of reporting biases
Funnel plots (effect size versus standard error) will be drawn if sufficient studies are found. We recognize that symmetry of the plots may indicate publication bias, although they may also represent a true relationship between trial size and effect size. If such a relationship is identified, we will examine the clinical diversity of the studies as a possible explanation (Egger 1997).
Data synthesis
We will synthesis data using both a fixed effect and a random effects model.
Meta‐analysis will be performed where studies are considered to have sufficiently similar participants, interventions, comparators and outcome measures. In carrying out meta‐analysis, the weight given to each study will be the inverse of the variance so that the more precise estimates (from larger studies with more events) are given more weight. Outcome data for the two categories of intervention, behavioural/cognitive behavioural and psychodynamic, will be analysed separately.
Subgroup analysis and investigation of heterogeneity
If sufficient studies are found, we will undertake subgroup analysis by severity of offending and type of intervention (e.g., classic behavioural‐only interventions such as aversion therapy).
Sensitivity analysis
We will use sensitivity analysis to assess the impact of study quality if there is sufficient data, particularly to consider the potential impact of outcome assessors being blinded, or not.
We will also undertake a sensitivity analysis to investigate the robustness of the overall findings where there has been uncertainty or disagreement regarding, for example, the inclusion of studies, data extraction or missing data, or in the event of one or more large studies dominating the results.
