Forensic aspects of intellectual disabilities and autism spectrum disorders

Nugent, Stella (2016) Forensic aspects of intellectual disabilities and autism spectrum disorders. DForenPsy thesis, University of Nottingham.

[img] PDF (Forensic Aspects of Intellectual Disabilities and Autism Spectrum Disorders) (Thesis - as examined) - Repository staff only - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (2MB)



This thesis reviewed forensic aspects of Intellectual Disabilities (ID) and Autism Spectrum Disorder (ASD). Chapter two was a case study where an individual with ID and ASD who exhibited forensic/Challenging Behaviour (CB) was assessed and intervention offered. Chapter three then focussed on the assessment of people with ID and ASD by critiquing the Wechsler Adult Intelligence Scale (WAIS), version 3 and 4 (WAIS-III & WAIS-IV) (Wechsler, 1997; Wechsler, 2008a, 2008b, 2008c) and discussed application issues for people with ID and ASD. Chapter 4 and 5 examined intervention in more depth. Chapter 4 applied Weiner’s (1985, 1993) theory of achievement, motivation and emotion as a way of understanding contextual intervention and Chapter 5 examined the effect of psychotherapeutic interventions on CB.

Chapter Two

The case study discussed in chapter two examined explanations of violence and diagnoses. ASD and an ID were identified as useful neurodevelopmental diagnoses that could be used as a framework to understand the individual’s needs. Some explanations of violence were related to features of these diagnoses. Social factors were also identified as increasing risk. Violence was modelled by a key male figure during childhood development which appeared to have been retained as a template of acceptable behaviour, supporting the work of Bandura on social learning (1973). This, and the experience of being a victim of this violence, also supported the work of Douglas, Hart, Webster and Belfrage (2013) who indicated that social factors can increase the risk of violence. In turn this affected attachment supporting the work of Bowlby (1980). The behavioural approach (Cipani & Schock, 2010) was also applied to identify functions of violence.

A psychotherapeutic intervention was offered to improve one aspect of emotional recognition, face perception, with the aim of enabling him to comprehend visual feedback from the environment, make interpretations about the emotions experienced by others, and modify his behaviour accordingly. There was little difference to his level of skills following the intervention. It was concluded that particular skills development may be difficult for someone with a neurodevelopmental difficulty if the biological structures are not there to support that skill, or skills may take a long time to develop. In this case it was concluded that the best intervention was to consider a placement for him in an appropriate environment that would cater for his ASD and ID related needs. Comments were made about the quality of assessments and for improvements to be considered to formulation and intervention.

Chapter Three

Chapter three was a critique of the WAIS, a tool widely used as part of the process to identify whether someone has an ID. This may determine if an individual may be unfit to plead in court or to determine the services appropriate for that individual’s needs. The review focussed on the most recent version, WAIS-IV (Wechsler, 2008a, 2008b, 2008c) but also referred to other versions in particular the WAIS-III (Wechsler, 1997). The conclusion was there were some flaws to the assessments that required further research and also some omissions in the epistemology.

The critique examined different aspects of validity and reliability. The examination of convergent validity yielded mixed results with some positive correlations with other tests and some weak correlations. This difference could be caused by some tests measuring different aspects of ‘g’. The consequences of differences can be significant, for example the scores of the Wechsler Intelligence Scale for Children, version 4 (WISC-IV) (Wechsler, 2003) and the WAIS-IV scores could differ by up to 10 points and could mean individuals moving from a children’s to an adult service could become ineligible for the same levels of support. The results for test-retest reliability were good in the short term but more research was recommended to determine if the latest version of the WAIS would be reliable in the long term. The ‘Flynn effect’ (Flynn, 2007) indicated that levels of intelligence were rising so the WAIS-IV compensated for this and currently measures intelligence at around 3 points lower than the WAIS-III. The stability of this effect was unclear.

The results for internal reliability were good although more research independent of the WAIS was recommended. The application of the WAIS for individuals with an ASD and ID was considered with the WAIS being found to be a limited tool for discriminating between categories of ASD, although what can be expected is an uneven profile. It was also unclear how useful the WAIS was to discriminate between individuals with a substance misuse/abuse disorder and normal controls. There were also difficulties with the application of the WAIS to individuals with ID. Difficulties measuring intelligence at lower levels were identified as scores can be unstable. Research was also recommended to provide a comprehensive view of the effect upon results of variables such as nationality, gender and age.

Chapter Four

Chapter four was an empirical research project investigating Weiner’s (1985, 1993) theory of achievement, motivation and emotion as a means of understanding the responses of unqualified nursing staff to clients with ASD exhibiting CB. One hundred and twenty seven unqualified nursing staff responded to an Attributional Style Questionnaire (ASQ) (Dagnan & Cairns, 2004) and questions based on a vignette. The quantitative results found weak support for Weiner’s model. There was weak evidence for the effect of demographic variables and the type of client (ASD or ID) and the type of service (ASD or Mental Health/ID) did not affect the results. Qualitative data was themed and coded according to Braun and Clarke (2006) and Boyatzis (1998) and provided an insight into the psychological processes influencing staff responses to CB. The results suggested that intervention was influenced by staff, patient and contextual variables. A recommendation was made for a contemporary exploration of the topic and to improve the validity and reliability of the ASQ.

Chapter Five

Chapter five was a systematic review of psychotherapeutic interventions aimed at reducing the CB exhibited by people with ID only due to a paucity of research using people with ASD as participants. A systematic literature search was conducted using 5 databases, a search of relevant journals and contact made with experts. From this 8 papers met the inclusion/exclusion criteria and these were analysed qualitatively. Three types of psychotherapeutic intervention were used within the ten papers, Cognitive Behavioural Therapy (CBT), “Soles of the Feet” meditation and Solution-Focussed Brief Therapy. All types of psychotherapeutic intervention reduced CB although the results of studies using CBT were mixed. There were shortcomings to these conclusions; these were methodological issues such as a need to ensure the consistency of outcome measures and the types of CB used to measure change. The effect of intervention may have been modified by variables such as length of treatment, the context and intrapersonal variables.


The chapters of this research thesis indicated that neurodevelopmental factors influenced forensic/CB, although social role models, attachment and trauma were also significant. Assessments were important as they may affect fitness to plead and services/treatment offered. Assessments such as the WAIS are supported by research although further research has been recommended. The use of the WAIS with people with ASD and ID was limited as people with ASD appear to exhibit uneven profiles when completing the WAIS and there were inaccuracies when using the WAIS with people with lower levels of intelligence. The difficulties people with ASD have with social communication skills can also affect performance and support is needed when administering assessments.

Intervention for people with a neurodevelopmental difficulty can also be successful. Consideration is needed regarding appropriate intervention for each individual, how long before the intervention is effective, the context including the type of support offered and how that affects outcomes, intrapersonal variables such as intelligence, and whether the treatment includes one to one support. More research of an improved quality is required to determine the effectiveness of both assessment and treatment including contextual based treatment such as the interaction between staff and patients within an institutional setting. Considering these further would improve the service for this client group and contribute to a reduction of risk.

Item Type: Thesis (University of Nottingham only) (DForenPsy)
Supervisors: Egan, Vincent
Chou, Shihning
Whitfield, Kate
Duff, Simon
Keywords: Intellectual disabilities, Autism spectrum disorder Challenging behaviour
Subjects: W Medicine and related subjects (NLM Classification) > WM Psychiatry
Faculties/Schools: UK Campuses > Faculty of Medicine and Health Sciences > School of Medicine
Item ID: 34777
Depositing User: Nugent, Stella
Date Deposited: 10 Jan 2017 12:50
Last Modified: 19 Oct 2017 16:34

Actions (Archive Staff Only)

Edit View Edit View