The assessment and treatment of sex offenders with intellectual disabilities: A work in progress.

By Prof. Kasia Uzieblo & Marije Keulen-de Vos, PhD. (Dutch Chapter of the ATSA, NL-ATSA)

Contact: Kasia.Uzieblo@thomasmore.be

On June 11^th NL-ATSA, the Dutch Chapter of ATSA, organized a masterclass on the assessment and treatment of sex offenders with intellectual disabilities.in conjunction with the International Forensic Mental Health Services at the IAFMHS conference 2018 in Antwerp (Belgium).  

A considerable number of sex offenders exhibit intellectual disabilities (ID). These offenders require bespoke assessment, support, and treatment. However, in practice ID and its role in sexual deviant behavior are not always fully recognized nor well understood. To enhance the effectiveness of support and treatment programs for sex offenders with ID, it is of great importance for professionals to be aware of the presence of the ID’s, to understand its influence on (sexual) behavior, and to have knowledge of effective treatment programs.

By organizing this masterclass, we also wanted to honor the works of Prof. William R. Lindsay who unfortunately has passed away in March 2017. William Lindsay had dedicated his career to further our understanding of offending behavior among people with ID and to improve assessment and treatment tools in these offenders. He was mainly passionate about identifying the pathways into forensic services of ID offenders, developing adequate assessment tools and establishing effective, evidence-based treatment programs for these offenders. Notwithstanding his very busy research agenda, he also found sufficient time throughout his career to acquire extensive clinical experience with ID offenders: To honor his invaluable work, the masterclass gave ample attention to Prof. Lindsay’s research throughout all sessions. In order to ensure that in-depth insights into Prof. Lindsay’s views and work would be shared, only presenters who had collaborated with Prof. Lindsay in terms of education and/or research were included in the program.

The presenters of the first session, Prof. Kasia Uzieblo (Thomas More and Ghent University, Belgium) and Dr. Petra Habets (OPZC Rekem, Belgium), focused on the assessment of ID in offenders, a topic that even in books on (sex) offenders with ID is often being overlooked. Given the important consequences of an ID diagnosis in offenders, this observation is rather striking. There is ample evidence showing that the assessment of ID in both research and practice comprise several substantial problems and limitations and does not sufficiently adapt to significant evolutions in intelligence research. The convergent validity of the current measures for IQ (e.g., the Wechsler Scales and the Raven’s Progressive Matrices) exhibits substantial problems. For instance, a study by Habets, Jeandarme, Uzieblo, Oei, and Bogaerts (2014) showed that despite positive correlations among intelligence measures, differences between scores on repeated and different IQ measures of 10 points and more occur far too often. In addition, current intelligence measures seem to not sufficiently tap into the various intellectual abilities as described in current theoretical frameworks of intelligence, including the Cattell-Horn-Carroll Model (CHC-model). Another assessment problem arises when taking into account the second diagnostic criterion of ID, i.e. deficits in adaptive functioning. In contrast to previous editions, the fifth version of the Diagnostic and Statistical Manual for Mental Disorders as well as the upcoming 11^th edition of the International Classification of Diseases (ICD-11) underline that it is not the IQ score but rather the level of adaptive functioning that determines the level of support needed. Hence, a reliable assessment of adaptive functioning on the conceptual, social and practical domain becomes of utter importance. However, adaptive functioning is often neglected in the assessment procedures or is not sufficiently taken into account when diagnosing ID. This problem might be intertwined with another issue: There is a lack of reliable, valid, and comprehensive measures for adaptive functioning. Unfortunately, this is not all. Many additional problems, including the lack of culturally fair assessment practices and the effect of comorbid psychiatric disorders on ID assessment, merit attention. In sum, Uzieblo and Habets highlighted the need for adequate, comprehensive assessment procedures for ID that align with the most recent theoretical frameworks of intelligence.

The second presenter, Prof. Leam A. Craig (University of Birmingham, UK), focused on the prevalence of ID in sex offenders, etiological explanations of sexual offending behavior in ID offenders, treatment effects, and risk assessment. Prevalence rates of sex offenders with ID typically range from 21 to 50%. However, we have no way of knowing how accurate these percentages actually are. Prof. Craig offered several etiological explanations of sexual offending in offenders with ID. Some studies on sexual abuse in people with ID suggest that behavioral problems (i.e., sexual inhibition) are a consequence of sexual abuse but not of physical abuse. Another hypothesis is that sex offenders with ID are more impulsive than their non-disabled counterparts, although findings on grooming suggest that individuals with ID do demonstrate delayed gratification. One of the most influential explanations is the counterfeit-deviance hypothesis which assumes that sexual deviant behavior is precipitated by a lack of sexual knowledge, poor social skills, limited opportunities, and sexual naivety rather than deviant sexual interests. However, several studies contradict this assumption. In sum, the developmental pathways into sexual offending in people with ID are not well understood yet. With regard to treatment programs for sex offenders with ID, CBT principles are the most commonly applied in these programs. But two problems occur. These programs are typically based on existing non-ID programs. And there is empirical support for their effectiveness. The latter is partly due to methodological problems, such as few randomized clinical trials and the fact that comparison groups are often not available. Next, Prof. Craig provided an overview of commonly used risk methodologies and instruments. Often, the same instruments are used in offenders with ID and non-ID offenders, such as the SVR-20, Static-99, and the Risk Matrix-2000. The ARMIDILLO-S is an instrument specifically developed for sex offenders with ID. Because of the extensive use of risk assessment within the management and treatment of sexual offenders with ID, the accuracy of predictions is of utmost importance. Prediction, however, remains a tricky thing. We have to be aware of what we are actually predicting. Also, the predictive value of risk offender instruments is dependent on definitions of sexual deviant behavior, sex offender ID characteristics (e.g., higher incidence of family psychopathology, behavioral disturbances at school, sexual naivety, and poor impulse control) and base rates. Given the variation in base rates and recidivism rates across risk categories
in samples of sexual offenders with ID, it appears that it is more helpful to report relative levels of risk rather than absolute rates of recidivism.

In the final presentation, Prof. John Taylor (Northumbria University, UK) discussed several tools for practice. He specifically focused on the added value of Finkelhor’s precondition offending model as a shared multidisciplinary and valuable approach. In this approach, the motivation to sexually offend is dissected in four stages. Stage 1 focuses on aspects that influence motivation, such as sexual arousal to inappropriate stimuli and experience of abuse. Stage 2 addresses overcoming self-control. More specifically, cognitive distortions, stress, drug/alcohol abuse and organic factors may lead to disinhibition. Stage 3 emphasizes external control. For example, external factors such as social isolation, discontinuation of supervision or structure, and unusual living/sleeping arrangement may increase the risk of offending. Finally, stage 4 focuses on overcoming victim resistance. Different influencing factors may be prominent in different offenders. Based on these factors, an individualized risk management plan including the level of risk, probability of risk, clinical interventions and management strategies can be developed. In the Northgate Sex Offender Treatment Program (Northumberland, Tyne & Wear NHS Foundation Trust) patients are encouraged to work through three developmental levels over the course of 12-24 months. First (phase 1, pre-treatment group) patients are desensitized to working in a group setting. Next (phase 2, intermediate group, patients are encouraged to discuss more personal issues, emotional difficulties and other things they would like to change. Finally (phase 3, is the offence related group), patients are encouraged to consider behavior related to their offences.

Several discussions with the participants during the masterclass indicated that many practitioners are struggling with the assessment in and treatment of ID offenders. There is clearly an urgent need to share best practices and to develop evidence-based assessment and treatment tools for practice. Since Prof. Lindsay has highlighted these necessities in his first studies, this field has moved forward, mainly thanks to his work. But we are obviously not there yet, as was made very clear throughout the presentations. Hence, it is of vital importance that experts, including Leam Craig, John Taylor and many others working with ID offenders, will proceed with their invaluable work in research and practice. We should also remain working on that two-way bridge between research and practice that Prof. Lindsay had been striving for. Maybe it is utopian to think that we will ever find a solution for all the problems we encounter when working with ID offenders. But nevertheless, we should follow in the footsteps of William Lindsay, and at least aspire to reach this destination.

Want to know more about the aforementioned topics? Some good reads:

Craig, L. A. (2010). Controversies in assessing risk and deviancy in sex offenders with intellectual disabilities. Psychology, Crime & Law, 16(1-2), 75-101.

Craig, L. A., & Lindsay, W. R (2010) Sexual offenders with intellectual disabilities: Characteristics and prevalence. In, L. A. Craig., W. R. Lindsay., & K. D. Browne, (Eds.), Assessment and Treatment of Sexual Offenders with Intellectual Disabilities: A Handbook. (pp. 13-36). Wiley-Blackwell.

Craig, L.A., Stringer, I., & Moss T. (2006). Treating sexual offenders with learning disabilities in the community: a critical review. International Journal of Offender Therapy and Comparative Criminology, 50(4), 369-390.

Habets, P., Jeandarme, I., Uzieblo, K., Oei, K., & Bogaerts, S. (2015). Intelligence is in the eye of the beholder: investigating repeated IQ-measurements in forensic psychiatry. Journal of Applied Research In Intellectual Disabilities, 28(3), 182–192.

Lindsay, W.R., & Taylor, J.L. (2018). Offenders with Intellectual and Developmental Disabilities. Research, Training, and Practice. John Wiley & Sons Inc.

Taylor, J.L., & Halstead, S. (2001). Clinical Risk Assessment for People with Learning Disabilities who Offend. The British Journal of Forensic Practice, 3(1), 22-32.

Uzieblo, K., Winter, J., Vanderfaeillie, J., Rossi, G., & Magez, W. (2012). Intelligent diagnosing of intellectual disabilities in offenders: food for thought. Behavioral Sciences & the Law, 30(1), 28–48.