Does the adapted sex offender treatment programme reduce cognitive distortions? A meta-analysis
| DOI | https://doi.org/10.1108/JIDOB-08-2017-0018 |
| Pages | 9-21 |
| Date | 12 March 2018 |
| Published date | 12 March 2018 |
| Author | Chris Patterson |
| Subject Matter | Health & social care,Learning & intellectual disabilities,Offending behaviour,Sociology,Sociology of crime & law,Deviant behaviour,Education,Special education/gifted education,Emotional/behavioural disorders |
Does the adapted sex offender treatment
programme reduce cognitive distortions?
A meta-analysis
Chris Patterson
Abstract
Purpose –For the 3.8per cent of people with intellectualdisabilities (IDs)who have offended sexually,the main
form of treatment is the group-based, cognitive-behavioural, adapted sex offender treatment programme
(ASOTP)that focusses on challengingcognitive distortionscondoning sex offending.The purpose of this paper
is to provide an evaluation of how effective theASOTP is at reducing ID sex offenders’cognitive distortions.
Design/methodology/approach –Three databases were searched systematically: PsycINFO, MEDLINE
and Web of Science. Six studies met the inclusion criteria, yielding 118 participants. Using a random-effects
model,effect sizes were calculatedusing pre- and post-treatmentscores on a measure of cognitivedistortions.
The standardised mean difference (SMD) was 1.77 (95 per cent CI: 1.06, 2.46), which was statistically
significant(p o0.001)and “large”. Sensitivity analysisdemonstrated that this SMD wasrobust, and a check for
publication bias revealed that it was unlikely thatthe “file drawer problem”confounded themeta-analysis.
Findings –These results indicated that the ASOTP can significantly reduce ID sex offenders’cognitive
distortions, regardless of treatment length, IQ level, language abilities, or offence type. Consistent with earlier
reports, longer treatment resulted in the greatest reductions: the optimum treatment length was 24 months.
Research limitations/implications –The ASOTP’s current evidence is comprised wholly of case and
quasi-experimental studies, none of which employed control groups. This paper highlights how there is a dire
need for high-quality experimental evaluation of the ASOTP.
Practical implications –Clinicians are advised to continue using the ASOTP as the main treatment for ID
sex offenders until the effectiveness of the ASOTP is further examined using randomised controlled trials.
Originality/value –This is the first meta-analytic review of the effectiveness of the ASOTP.
Keywords Intellectual disability, Meta-analysis, Sex offenders, Cognitive distortions,
Sex offender treatment programme, Sex offending
Paper type Literature review
Introduction
In the early 1990s, the sex offender treatment programme (SOTP) –group-based
cognitive-behavioural treatment for sex offenders –was piloted across a number of prisons in
the UK. Prior to this, sex offender treatment was dominated by behavioural interventions, such as
aversion therapy (to decrease inappropriate sexual arousal) and masturbatory reconditioning
(to increase appropriate sexual arousal) (Brown, 2010), which were believed to be unethical
(Hall, 1995; Quinsey and Earls, 1990; Laws and Marshall, 2003) and unsupported by evidence
(Wakeling et al., 2005). Evidence initially suggested that the SOTP reduced recidivism rates
significantly better than earlier behavioural interventions (Hanson et al., 2002). The Ministry of
Justice have recently evaluated the impact of their prison-based SOTP, and reported that
10 per cent of treatment completers had committed a further sexual offence after eight years.
This was significantly higher than the 8 per cent of matched controls that committed a further
sexual offence in the same follow-up period (Mews et al., 2017).
Notably, the SOTP’s inclusion/exclusion criteria stipulated that its recipients must have IQs of 80
or above, as it was believed that individuals with IQs of 79 or below could not benefit from CBT as
Received 19 August 2017
Revised 19 October 2017
Accepted 21 October 2017
Chris Patterson is a Trainee
Clinical Psychologist at Bangor
University, Bangor, UK.
DOI 10.1108/JIDOB-08-2017-0018 VOL. 9 NO.1 2018, pp. 9-21, © Emerald Publishing Limited, ISSN 2050-8824
j
JOURNAL OF INTELLECTUAL DISABILITIES AND OFFENDING BEHAVIOUR
j
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