‘Diagnostic Overshadowing’ Amongst Clinicians Working with People with Intellectual Disabilities in the UK

Background Mental health problems are known to be hard to recognize in people with intellectual disabilities. One factor that may contribute to this is the diagnostic overshadowing bias, which describes the tendency of the clinicians to overlook symptoms of mental health problems in this client group and attribute them to being part of ‘having an intellectual disability’. Although a small amount of research has investigated this in the USA, very little has taken place in the UK. Materials and methods Two clinical vignettes were produced. Both described identical clinical problems, except that one vignette described a man with an IQ of 58 and impaired social functioning (i.e. an intellectual disability) and one a man with an IQ of 108 and normal social functioning (i.e. non‐intellectually impaired). Psychiatrists (n = 274) and clinical psychologists (n = 412) throughout UK were randomly assigned to either the low IQ or normal IQ condition, and sent a corresponding clinical vignette. Results One hundred and thirty‐three psychologists and 90 psychiatrists responded. Diagnostic overshadowing did appear to be present. Clinicians were more likely to recognize a range of symptoms in those with IQs in the normal range than those with intellectual disabilities. Furthermore, psychiatrists appeared more likely to make this error under some circumstances than clinical psychologists. Conclusions Diagnostic overshadowing may contribute to the difficulties that mental health professionals commonly experience in identifying mental health problems in people with intellectual disabilities. However, the methodology commonly used in this type of research has a number of weaknesses, and would benefit from an alternative approach.     

The Prevalence and Determinants of Obesity in Adults with Intellectual Disabilities

Background Obesity is a major public health concern internationally and this study aimed to measure the prevalence of obesity in adults with intellectual disabilities in comparison with general population data, and examine the factors associated with obesity. Methods This was a cross‐sectional study of all adults with intellectual disabilities, in a defined geographical area, in the context of a primary care health screening programme. A total of 945 adults with intellectual disabilities were involved, all of whom were living in the community. Body mass index (BMI), demographic characteristics, socio‐economic deprivation, level of intellectual disabilities and various health parameters were measured. Results Overall, 39.3% of women and 27.8% of men were obese, compared with 25.1% of women and 22.7% of men in the comparison general population. The mean BMI of women with intellectual disabilities (28.8, range 12.3–59, SD 7.8) was significantly greater than the mean BMI of men with intellectual disabilities (26.7, range 12.6–49, SD 5.9), and women were more likely to be obese than men with intellectual disabilities (χ² = 29.6, P < 0.001). Regression analyses showed that for both women and men, the risk of overweight and obesity reduced as the severity of intellectual disabilities increased, and Down syndrome was associated with an increased risk of overweight and obesity. Conclusions There is a need to carry out research to further our understanding of the reasons behind the increased prevalence of obesity in adults with intellectual disabilities. Effective weight management interventions and accessible clinical services are required to reduce the health inequalities experienced by adults with intellectual disabilities.     

Health in People with Intellectual Disabilities: Current Knowledge and Gaps in Knowledge

Background The health needs of people with intellectual disabilities have recently received increasing attention. Method Based on a review of the 2003 literature, this paper presents an overview of our knowledge on physical, mental and social well‐being in this group. Results Physical well‐being is threatened by handicap‐related conditions, syndrome‐related health problems and lifestyle characteristics. Conclusion Gaps in knowledge include insufficient evidence on health disparities, the lack of comparability of data on the prevalence of ill heath, lack of expertise in relation to communication problems and the fact that all knowledge is based on research in developed countries, while people with intellectual disabilities in developing countries face the same or even greater health problems. Recommendations concerning evidence, education and empowerment are formulated.     

Comparison of the WAIS‐III and WISC‐IV in 16‐Year‐Old Special Education Students

Background Previous research with earlier versions of the WISC and WAIS has demonstrated that when administered to people who have intellectual disabilities, the WAIS produced higher IQ scores than the WISC. The aim of this study was to examine whether these differences still exist. A comparison of the Wechsler Adult Intelligence Scale – Third Edition (WAIS‐III) with the Wechsler Intelligence Scale for Children – Fourth Edition (WISC‐IV) was conducted with individuals who were 16 years old and receiving special education. Materials and Methods All participants completed the WAIS‐III (UK) and WISC‐IV (UK). The order of administration was counterbalanced; the mean Full Scale IQ and Index scores on the WAIS‐III and WISC‐IV were compared. Results The WAIS‐III mean Full Scale IQ was 11.82 points higher than the mean Full Scale IQ score on the WISC‐IV. Significant differences were also found between the Verbal Comprehension Index, Perceptual Reasoning/Organization Index and Processing Speed Index on the WAIS‐III and WISC‐IV, all with the WAIS‐III scoring higher. Conclusions The findings suggest that the WAIS‐III produces higher scores than the WISC‐IV in people with intellectual disabilities. This has implications for definitions of intellectual disability and suggests that Psychologists should be cautious when interpreting and reporting IQ scores on the WAIS‐III and WISC‐IV.     

Patients', Family Members', and Professional Carers' Experiences of Psychoeducational Multifamily Groups for Participants with Intellectual Disabilities and Mental Illness

There is a dearth of articles addressing psychoeducational multifamily groups for adults with intellectual disabilities. The objective of this study is to investigate the participants' experiences of being part of a group like this. The group intervention had been slightly modified due to the participants' intellectual disabilities. Four patients, their close relatives, and community professional caregivers were interviewed using a semi-structured scheme. The four patients had participated in different groups. Three of them had autism spectrum disorder in addition to intellectual disabilities and mental illness. None of the patients were in the most acute phase during the group intervention. Topics discussed in the group sessions encompassed friendship, personal economy, hygiene, understanding of mental illness, and the need for help. A basic meal was served at every group meeting. The experiences were favorable.     

Talking About Real‐life Events: An Investigation Into the Ability of People with Intellectual Disabilities to Make Links Between Their Beliefs and Emotions Within Dialogue

Background This study compares how people with and without intellectual disabilities talk about events, beliefs and emotions in dialogues about real‐life, emotive events and in a structured task assessing understanding of cognitive mediation. Materials and Methods A cognitive‐emotive interview was used to assist 19 adults with intellectual disabilities and 19 adults without disabilities in generating an account of an emotive, interpersonal event. Participants also completed a cognitive mediation task and an assessment of intellectual and verbal ability. Results Between‐group analyses indicated that participants with intellectual disabilities scored significantly lower than those without disabilities on the cognitive‐emotive interview and the cognitive mediation task. Participants with intellectual disabilities generated fewer beliefs within their dialogues and were less likely to provide alternative perspectives on events. Within‐group comparisons showed no significant association between the ability to talk about events, beliefs and emotions within a dialogue and performance on a cognitive mediation task, or with Full Scale or Verbal IQ scores. Conclusions Participants with intellectual disabilities had more difficulties than those without disabilities in talking about events, beliefs and emotions. Within a therapeutic context, they are likely to require assistance to reflect on events and consider alternative interpretations, which take into account individual and environmental factors. Future therapeutic developments may benefit from placing greater emphasis on emotional understanding and the intuitive links that people make between events and emotions.     

A Prevalence Study of Sexual Abuse of Adults with Intellectual Disabilities Referred for Sex Education

This paper reports on a prevalence study of sexual abuse of 65 women and 120 men with intellectual disabilities who were referred for sex education. The prevalence rate of abuse was found to be significantly higher for women (61%) than men (25%). Almost all perpetrators were men, with the majority being men with intellectual disabilities or fathers. Women are shown to experience the sexual contact more negatively than the men, although it was usual for both the women and men to feel quite ambivalent about the perpetrator and what he had done to them. Typically the abuse was revealed by the victims themselves, but they were unaware of its social meaning. Generally responses to the abuse were very weak, however there is evidence that the abuse of men is taken more seriously. The poorest service responses were recorded for women who had been abused by men with intellectual disabilities.     

Assessing Components of Empathy in Sex‐ Offenders with Intellectual Disabilities

Background Because of a lack of research investigating empathy in sex offenders with intellectual disabilities, this study explored empathy in sex offenders and non‐offenders with intellectual disabilities. Specific aims were to explore differences between these groups on measures of the components of empathy. Methods The scores of 21 sex‐offenders and 21 non‐offenders with intellectual disabilities, matched by age, gender and IQ, were compared on the Test of Emotional Perception. Results No differences were found between the two groups across the components of empathy. However, sex offenders who had received treatment performed better on tasks of emotion recognition, emotion replication and response decision than the non‐offenders. Conclusions Further research is needed to understand empathy in sex offenders with intellectual disabilities before any recommendations can be made regarding treatment programmes.     

Age Recognition in Adults with Intellectual Disabilities: a Literature Review and an Exploratory Study

The ability of children to classify accurately their own ages and the ages of others has been the subject of very limited research. However, the literature is largely in agreement on there being progressive increases in skill with chronological age, although there is disagreement on the age at which this ability becomes well developed. The processes look similar in the field of intellectual disabilities, although this area is extremely under‐researched. Key factors may include age, the amount of time spent in institutions (e.g. long‐term hospitals for people with intellectual disabilities), developmental level and IQ. The present paper provides a review of the relevant literature and an exploratory study investigating the age recognition of self and colleagues in a group of 20 adults with intellectual disability, some from within what has been a major hospital for people with intellectual disabilities and some from the wider community. Measures of age recognition using photographs, as well as standardized measures of intellectual ability and social adaptive behaviour, were administered, and correlations were found between the ability to recognize age in others and developmental age, and also IQ. Success on the task of age discrimination appears to be more likely if the IQ of the individual is around 60–65 or above, and if the person shows social adaptive behaviour equivalent to 8 or 9 years of age and over. Also included in the study was a task in which only the discrimination of whether the photographs were of adults or children was required, and this proved to be a simpler process for the participants. The present study also demonstrates some of the discriminative stimuli used by adults with intellectual disabilities to ascertain the approximate age of a person.     

Coins and Costs: A Simple and Rapid Assessment of Basic Financial Knowledge

Introduction We describe a simple and rapid screening test for basic financial knowledge that is suitable for administration to people with mild intellectual disabilities. Method The Coins and Costs test asks respondents to name coins, and to estimate prices of objects ranging between £1 (an ice cream) and £100K (a small house). The test was administered, alongside a battery of neuropsychological tests, to 40 people attending day services (mean Full‐Scale IQ = 59.1). Results Total scores were normally distributed, and correlated significantly with receptive language ability and performance on memory tests, but not with IQ or executive functioning. Conclusion The test provides a rapid (<5 min) screening test that has good psychometric properties and appears very suitable for assessing basic financial knowledge of people with mild intellectual disabilities.     

The Contribution of Academic Skills to the Successful Inclusion of Children with Disabilities

Data relating to academic ability were collected for 24 students with disabilities who had been included in regular education classes for 18 months or more. Norm-referenced literacy measures were collected for all 24 students and for 19 of them peer-micronormed literacy and numeracy work samples were obtained and compared to samples collected on average teacher-nominated peers in each of their classes. In addition, teachers were interviewed for their perceptions of the literacy and numeracy skills of the students compared with typical grade peers and their perceptions of the success of the integration. While most of the students performed below their age peers on all measures, some students (even students who had been diagnosed as having a moderate intellectual disability) performed close to and occasionally above what would be expected for their age/grade. There was a positive and statistically significant relationship between the direct measure of academic skills and class teacher perception of those skills and between the perceptions of independent observers who rated the work samples and the direct measure of academic skills. While a relationship was found between teacher rating of success and academic ability, no clear relationship was found between level of disability, as measured at the preschool level, and academic ability. Implications of these findings are discussed.     

Utility of the Brief Symptom Inventory in the Assessment of Psychological Distress

Introduction People with intellectual disabilities are now acknowledged to be susceptible to the full range of mental health disorders. This acknowledgement has resulted in the need to develop and evaluate instruments for the assessment and detection of mental health problems. This research evaluates the use of the Brief Symptom Inventory (BSI) with 200 people with mild intellectual disabilities representing community, clinical and forensic populations. Results and conclusions Results illustrate the reliability of the BSI for each of the groups and demonstrates how the Positive Symptom Total (PST) index effectively discriminates between study groups. Case rates for each group are provided. The study illustrates that the BSI could be employed as a brief multitrait assessment instrument and as a treatment outcome measure with people with an intellectual disability.     

A Randomized Controlled Trial of a Specialist Liaison Worker Model for Young People with Intellectual Disabilities with Challenging Behaviour and Mental Health Needs

Background Twenty six young people with intellectual disabilities and mental health needs from Pakistani and Bangladeshi communities were recruited as part of a bigger study to examine the effectiveness of a liaison worker in helping young people and their families access appropriate intellectual disabilities and mental health services. Method Twelve young people were randomly allocated to the treatment group, which had the help of the liaison worker, and 14 young people were allocated to the control group without the help of a liaison worker. Baseline measures were undertaken with all the young people and their carers. This was followed by a 9‐month trial, consisting of the liaison worker helping the treatment group to get in touch with and take up appropriate services, mainly in the areas of psychiatric appointments, benefits advice, house adaptations, leisure facilities and support and care for the young person. The control group participants did not have the access to the liaison worker and were accessing services using the normal routine. Assessments were carried out post‐treatment to assess whether the use of a liaison worker had had any effect on outcomes for the two groups. Results Twelve young people completed the study in the treatment group and 14 in the control group. Participants allocated to the specialist liaison worker had statistically significantly more frequent contact with services and with more outcomes, than the control group, and significantly lower scores on the Strengths and Difficulties Questionnaire (SDQ). Conclusion The use of specialist liaison services in ensuring adequate access to services for young people with learning disabilities and mental health needs from the South Asian community proved to be significant and effective compared with young people and their families accessing services on their own.     

Specialist Versus Generic Models of Psychiatry Training and Service Provision for People with Intellectual Disabilities

Background Models of service provision and professional training differ between countries. This study aims to investigate a specialist intellectual disabilities model and a generic mental health model, specifically comparing psychiatrists’ knowledge and competencies, and service quality and accessibility in meeting the mental health needs of people with intellectual disabilities. Method Data were collected from consultant and trainee psychiatrists within a specialist intellectual disabilities model (UK) and a generic mental health model (Australia). Results The sample sizes were 294 (UK) and 205 (Australia). Statistically significant differences were found, with UK participants having positive views about the specialist intellectual disabilities service model they worked within, demonstrating flexible and accessible working practices and service provision, responsive to the range of mental health needs of the population with intellectual disabilities, and providing a wide range of treatments and supports. The UK participants were knowledgeable, well trained and confident in their work. They wanted to work with people with intellectual disabilities. In all of these areas, the converse was found from the Australian generic mental health service model. Conclusions The specialist intellectual disabilities model of service provision and training has advantages over the generic mental health model.     

OFFENDING BY ADULTS WITH LEARNING DISABILITIES: IDENTIFYING NEED IN ONE HEALTH DISTRICT

The extent to which adults in one health district with intellectual disabilities engaged in offending behaviour and the nature of their need was investigated in a series of three studies. First, the number of adults who reported having learning difficulties or who had attended special needs schools, in a consecutive series of adults charged at a city police station over a two-month period, was identified. Secondly, the extent and nature of offending by those living in residential placements for people with learning disabilities was ascertained retrospectively for the year 1992. In addition, the policies and responses of the residences' managers to offending behaviour were ascertained. Thirdly, a case control study of the outcome in the criminal justice process of those with self-reported learning disabilities identified in Study One was undertaken. Twelve (4.4%) of the 251 people arrested and screened at the city police station had been to a special school for children with mild or severe learning disabilities. Seven (2%) of 358 adults living in residential placements for adults with learning disabilities had been interviewed by police because of an alleged offence. None of this group appeared in Court despite the seriousness of some offences. In Study One, seven (58%) were sentenced by the Courts. None received a prison sentence or were diverted to the health service. The lack of established links between the criminal justice agency and other services and the experience and attitudes of staff in the different agencies both hindered the recognition of the presence of a possible learning disability and also prevented referral across agencies. These and social factors, such as homelessness, all contributed to a failure to provide for the needs of this minority of adults with learning disabilities who became involved in the criminal justice system.     

Profiling the Sexually Abusive Behaviour of Men with Intellectual Disabilities

Of a total of 120 men with intellectual disabilities who were referred for sex education, 75 had allegedly perpetrated some form of sexual abuse. Presented here is a statistical analysis of the offences that these men committed and the responses they received. The most common victims are shown to be people with intellectual disabilities, women staff, children and women in the general public. Variation is found between the nature of the offences across victim groups, with people with intellectual disabilities being on the receiving end of the most serious forms of assault Seriousness of the assaults was also found to be dependent on the ability of the perpetrator. The responses to the men were not found to be correlated with the nature of the sexual abuse but to whom was abused: the abuse of children and women in the general public giving rise to the strongest responses. Protection of victims from subsequent abuse was also related to this specific variable: here people with intellectual disabilities and women staff gained the least protection. Attempts to isolate predictive factors of abusive behaviour proved unsuccessful. For example, abusers and non-abusers within the sample had experienced sexual abuse themselves at similar rates. The study draws attention to the high proportion of men receiving intellectual disability services who appear not to have intellectual disabilities and the poor level of risk management of men with histories of sexually abusing.     

Schizophrenia in autistic people with intellectual disabilities: Symptom manifestations and identification

Background

The assessment of schizophrenia in autistic people with intellectual disabilities is challenging. This study aimed to explore the identification of schizophrenia in this population.

Methods

Using data from a clinical multi-centre study, reported symptoms in 26 autistic individuals with intellectual disabilities diagnosed with co-occurring schizophrenia were explored. Scores on two checklists (Psychopathology in Autism Checklist [PAC], Aberrant Behaviour Checklist [ABC]) were compared with two comparison groups: autistic individuals with intellectual disabilities and other mental disorders (94), or no mental disorder (63).

Results

Reported symptoms of schizophrenia in this population met the formal diagnostic criteria. For PAC/ABC scales, only PAC psychosis differed for the schizophrenia group. Among participants with schizophrenia, two were diagnosed with additional mental disorders. Elevated scores for anxiety and depression were common.

Conclusions

Emphasising core symptoms seems necessary when assessing co-occurring schizophrenia in autistic people with intellectual disabilities. The PAC may serve as a helpful screening tool.