The treatment and management of sex offenders with an intellectual disability

Submitting Institution

University of Abertay Dundee

Unit of Assessment

Psychology, Psychiatry and Neuroscience

Summary Impact Type


Research Subject Area(s)

Medical and Health Sciences: Clinical Sciences, Public Health and Health Services
Studies In Human Society: Criminology

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Summary of the impact

We report on the development and use of a clinical tool designed to assess the distorted cognitions of sex offenders with an intellectual disability. The tool discriminates between offenders and non-offenders and individuals who offend against children and those who offend against adults. Over the review period it has become routinely used internationally in forensic services in the treatment and management of sex offenders with an intellectual disability. Practitioners using the tool now have a means of monitoring the effectiveness of their treatment of sex offenders with an intellectual disability. Prior to its publication, practitioners working with this cohort had no access to suitably validated measures of cognitive distortions and therefore no means of systematically monitoring the extent to which offenders in their treatment programme were still exhibiting cognitive distortions typically associated with offending behaviour.

Underpinning research

The concept of cognitive distortions is widely used across many areas of clinical practice and is becoming increasingly recognized as an important factor in the aetiology and maintenance of psychological disorders. Initially, research that tried to explain the development of sexual offending focused on theories of deviant sexual arousal, the sexual or drug history of the offender, and/or their social skills relating to heterosexual relationships. More recently researchers have realised that studying cognitive distortions can provide better insights into the offence-related beliefs and motivations of individuals who sexually offend. The cognitive distortions include those that allow offenders to legitimise, justify, and rationalise their sexual offences — for example interpreting the precocious behaviour of a child as a sexual advance. . Since the late 90s, multifactorial rather than unidimensional models have been developed to examine sexual offending and the importance of cognitive distortions are well represented in these models.

Prior to the publication of the work outlined here, researchers working with offenders with an intellectual disability faced a number of problems. The tests and tools designed for use with the general population (i.e., sex offenders without an intellectual disability) were not suitable for use with offenders with an intellectual disability due to cognitive and linguistic limitations. With this group concepts need to be presented singularly and simply, and response requirements need to be similarly simplified.

Lindsay and Carson have worked together in this field since 1999 when they were awarded a grant from the Chief Scientist Office to develop and test the psychometric properties of a tool that measured such cognitions in this cohort (The Questionnaire on Attitudes Consistent with Sexual Offenders — QACSO). Whitefield, originally a research assistant employed on the grant, was awarded a PhD studentship from the University of Abertay in 2001 - 2003 to further the study of this topic under the supervision of Carson and Lindsay.

Pilot work for the development of the QACSO was originally carried out by Lindsay in his clinical work with sex offenders with a learning disability based in the Learning Disability Service of NHS Tayside, and subsequently published in The Journal of Intellectual Disability Research (JIDR) in 2003. After attracting support from the Chief Scientist Office, Lindsay and Carson further examined the early pilot data and tested the original QACSO test bank of 108 items on 4 groups of participants: normal men, sex offenders with a learning disability, offenders (but non sexual) with an intellectual disability, and individuals with an intellectual disability but no offence history. The items were tested for test-retest reliability, internal consistency, reading ease and discriminant validity of items and the subsequent sub-scales.

The revised QACSO published in Legal and Criminological Psychology in 2007 is a much reduced 63-item questionnaire specifically designed for use with sex offenders who have intellectual disability (ID). This protocol is designed to measure cognitive distortions commonly expressed by sexual offenders across eight domains: Rape and Attitudes to Women, Voyeurism, Exhibitionism, Dating Abuse, Homosexual Assault, Offences against Children, Stalking and Sexual Harassment and Social Desirability. The QACSO has been standardised on sexual offenders with ID, non-sexual offenders with ID, non-offenders with ID and mainstream males. The measure has been shown to discriminate sexual offenders with ID from non-offenders indicating particular cognitive distortions which facilitate offending behaviour in sexual offenders. The measure has good internal reliability, construct validity and test-retest reliability.

The QACSO remains the only tool developed to measure the cognitive distortions held specifically by sex offenders with an intellectual disability.

References to the research

Published Papers by Abertay researchers (Abertay researchers in bold)

Lindsay, W. R., Whitefield, E, and Carson, D. (2007). An Assessment for attitudes consistent with sexual offending for use with offenders with intellectual disability. Legal and Criminological Psychology, 12 (1),55-68. DOI: 10.1348/135532505X85882


Lindsay, W. R., Michie, A. M. Whitefield, E., Martin, V., Grieve, A. and Carson, D..(2006). Response Patterns on the Questionnaire on Attitudes Consistent with Sexual Offending in Groups of Sex Offenders with Intellectual Disabilities. Journal of Applied Research in Intellectual Disabilities. 19, 47-53.) DOI: 10.1111/j.1468-3148.2005.00288.x


Lindsay, W. R., Michie, A. M., Steptoe, L., Moore, F. and Haut, F. (2011), Comparing Offenders against Women and Offenders against Children on Treatment Outcome in Offenders with Intellectual Disability. Journal of Applied Research in Intellectual Disabilities, 24: 361-369. doi: 10.1111/j.1468-3148.2010.00615.x


• Broxhome, S.L and Lindsay, W.R. (2003). Development and preliminary evaluation of a questionnaire on cognitions related to sex offending for use with individuals who have mild intellectual disabilities. Journal of Intellectual Disability Research, 47, 472-482. DOI: 10.1046/j.1365-2788.2003.00510.x


Lindsay, W.R. (2005). Model underpinning treatment for sex offenders with mild intellectual disability: Current theories of sex offending. Mental Retardation*, 43(6), 428-441. * Now titled American Journal on Intellectual and Developmental Disabilities.[428:MUTFSO]2.0.CO;2


Conference Presentations

Lindsay, W.R., Carson, D.R. & Whitefield, E. (2000).`Development of a questionnaire on attitudes consistent with sex offending for men with intellectual disabilities'. 11th World Congress of the International Association for the Scientific Study of Intellectual Disabilities. Seattle, USA. August 1-6th 2000

Grant Awards.

• The development and evaluation of an assessment for the cognitions of sex offenders with intellectual disability. Scottish Executive. Chief Scientist's Office, 1999 - 2001. £35,000 awarded to Lindsay, W.R and Carson, D.R.

• The Role of cognitive processes and selective attention in sexual offending in people with ID/DD. Research Studentship, Univ. Abertay, Dundee. 2001-2003. £30,000 awarded to Lindsay, W.R and Carson, D.R.

Details of the impact

The main impact of the QACSO is that it is now a regularly used international clinical tool. It is commonly used:

  • as part of a baseline assessment to identify treatment need in clinical settings throughout the world;.
  • as part of a repeat evaluation process to identify treatment gain;.
  • as part of the risk assessment and management process, with regard to the identification of particular critical acute and stable dynamic risk factors;.
  • as a core research tool in the understanding of sex offending and the subsequent treatment of sex offenders with an intellectual disability.

Early versions of the QACSO were presented in 2000 by Lindsay at the World Congress of the International Association for the Scientific Study of Intellectual Disabilities. Seattle, USA and in 2002 at the BPS annual conference by Carson. Lindsay promoted the use of the updated 2007 version when asked to deliver workshops and keynote addresses at Annual Meyer's Oration at the Australian and New Zealand Association of Psychiatry, Psychology and Law in 2007 and when advising the Office of the Senior Practitioner on Criminal Justice Policy for Victoria, Australia in March 2011. The audience at these events consists of clinicians and potential users of the tool who tend to be based in clinical and forensic services. The tool and its manual were made freely available to suitably qualified individuals by contacting either Carson or Lindsay. The authors receive regular requests for access to the tool from clinicians across the world. In the recent past requests have come from practitioners based in the UK, Ireland, Canada, Australia, Japan, Korea and the USA (emails can be made available on request).

As a result, the tool is now widely used internationally. In Australia, clinicians in the Forensic Disability Service in Queensland regularly use it in the assessment of sex offenders with an intellectual disability, the risk such individuals pose to society and the evaluation of the services offered by the service. It is used in a similar fashion in the Department of Human Services Victoria and the State-wide Disability Service in New South Wales. In Canada, it is routinely used in clinical, risk and court assessments in Developmental Disabilities Consulting Program in Ontario.

The QACSO is used to assess individuals who have been identified as at risk of offending sexually and to reassess individuals attending treatment to identify risk of recidivism. In addition to discriminating between groups, the tool in its 2007 form, and indeed earlier in its pilot form, is used to monitor treatment progress. An example using the pilot version in this way is described in Murphy & Sinclair (2009).

The QACSO has been used by clinicians in Norwich Primary Care Trust to test the importance of locus of control in the treatment programmes of their patients. It is regularly used to test the efficacy of sex offender treatment programmes throughout the UK and beyond. It was used to evaluate a treatment programme for a group of men with intellectual disabilities based in a community setting in the Black Country Partnership NHS Foundation Trust (Rose, Rose, Hawkins and Anderson, 2012). The QACSO was employed by clinicians based in Oxleas NHS Trust to evaluate one of the first attempts to use cognitive behavioural therapy in treatment programmes designed for sex offenders with an intellectual disability (Murphy, Powell, Guzman and Hays, 2007). Similar evaluations of community-based cognitive behavioural treatment programmes in Northamptonshire (Craig, Stringer and Sanders, 2012); nursing led treatment programmes based in the Calderstones Partnership NHS Foundation Trust (MacNair, Woodward and Mount, 2010); and special needs community based programmes for convicted sexual offenders in Birmingham (Keeley, Rose and Beech, 2007) all used the QACSO as one of the core evaluation tools. The QACSO was one of the core outcome measures in a large-scale review of treatment programmes across a number of services and NHS areas in the Sex Offender Treatment Services Collaborative — Intellectual Disabilities (SOTSEC-ID) that formed a major study funded by the Department of Health.

The QACSO is cited and described in three Handbooks written primarily for clinicians and practitioners working in this field. The first "Assessment and Treatment of Sex Offenders: A Handbook" (Beech, Craig and Browne, 2009) focuses on the non intellectually disabled offender whereas "Assessment and Treament of Sexual Offenders with Intellectual Disability: A Handbook" (Craig, Lindsay and Browne, 2010) is written specifically for those working in services for the intellectually disabled offender. The third handbook is the more general, "Handbook for Forensic Mental Health" (Soothill, Rogers & Dolan (Eds.), 2008). The QACSO has also been cited in a review of the clinical tools available for the treatment of sex offenders throughout the UK and the wider world.

In 2011 UK experts (Professor Glynis Murphy, and Dr Neil Sinclair, neither associated with Abertay) visited Japan to train practitioners in this country in the treatment of sex offenders with an intellectual disability and recommended the QACSO as a validated tool for working with this population. As a result, Protection and Advocacy — Japan (PandA-J), a non-profit organisation who were in the process of setting up a sex offender treatment program requested at the time that they be allowed to translate the QACSO into Japanese. Permission was granted and the tool is now in use in the treatment programme. Similarly in 2011, the QACSO was translated into Korean in order that it be used in the Sex Offender Treatment Center based in the National Forensic Hospital, Republic of Korea.

Sources to corroborate the impact

  • Senior Practitioner / Forensic Psychologist, Office of the Senior Practitioner, Disability Services Division, Victorian Department of Human Services, AUSTRALIA.
  • Co-Director and Professor of Clinical Psychology and Disability, Tizard Centre.
  • Consultant Psychiatrist, Forensic Disability Service, Queensland, Australia.
  • Clinical and Forensic Psychologist, Assistant Professor of Psychiatry and Psychology, Clinical Director, Developmental Disabilities Consulting Program, Acting Chair, Division of Developmental Disabilities, Department of Psychiatry, Queen's University.
  • Consultant Clinical Psychologist, Black Country Partnership Foundation Trust.
  • Honorary Consultant Clinical and Forensic Psychologist, working at the Broadland Clinic, HPFT-Norfolk.
  • Forensic Clinical Psychologist, Sex Offender Treatment Centre, National Forensic Hospital, San 1, Bonggok-ri, Banpo-myeon, Gongju-si, Chungcheongnam-do, Republic of Korea.
  • Protection and Advocacy — Japan Yamaguchi Prefectural University