Patterns of offending among people with intellectual disability: a systematic review. Part II: predisposing factors

In the present study, the second part of a review of offending by adults with intellectual disability (ID), data on predisposing factors are presented and there is a discussion of the overall conclusions. The available data are shown to be problematic in a number of respects: there is no offence‐specific data; and a number of dimensions are under‐explored, specifically race, class and subjective accounts of offenders. Age and gender were the most highly correlated factors, as they are with offenders generally; however, there does appear to be evidence that the average age of offenders with ID is higher than for other offenders. The present authors note with concern the inattention to mainstream criminological research, and a tendency to downplay the extent to which an ‘offender’ is the outcome of complex and multifarious social processes. The authors also argue that the literature is dominated by unsubstantiated assumptions regarding the direction which policy and practice should take.     

Impulsiveness as a factor in sexual offending by people with mild intellectual disability

Background It has been suggested that sexual offending by people with intellectual disability (ID) results from a pattern of impulsive behaviour that is consistent with psychosocial disadvantage, rather than sexual deviancy. This study aimed to explore this hypothesis by assessing levels of impulsiveness in sexual offenders, non‐sexual offenders and non‐offenders with mild ID. Method Impulsiveness was assessed using a modified version of the Barratt Impulsiveness Scale (11th edition). Total impulsivity scores were compared between sexual offenders, non‐sexual offenders and non‐offenders, all with mild ID. Results There was a significant difference in the levels of impulsiveness between sexual offenders and non‐sexual offenders with ID (t = 2.83, P < 0.01). The sexual offenders were less impulsive than non‐sexual offenders. Conclusions This study did not support the hypothesis that sexual offending by people with ID is better explained by impulsive behaviour rather than sexual deviancy. It supports recent findings that among the general population, sexual offenders are less impulsive than controls and violent offenders.     

Assessing the prevalence of intellectual disability among young male prisoners

Background   In recent years, academic debate has (re)focused on the extent of the co-occurrence of intellectual disability (ID) and criminality, although findings from prevalence studies examining this link have been inconsistent. In April 2004, a process for transferring responsibility for commissioning healthcare services in UK prisons to Primary Care Trusts (PCTs) commenced. This development meant that it was important for PCTs to ascertain the need for specialist ID services in prisons in their areas. Because there were no reliable prevalence data, this research was commissioned by one such PCT.
Method   Using a stratified random sampling frame, data were collected from 185 young adult male prisoners aged 18 and 21 years old. Participants completed a semi-structured research questionnaire, the Kaufman Brief Intelligence Test (Second Edition) (KBIT2) and the Vineland Adaptive Behavior Scales (Second Edition) (VABS2).
Results   Ten per cent had an IQ composite of 69 or below, indicating a significant impairment in cognitive functioning. A further 10% had IQ composite scores between 70 and 74, and 14% between 75 and 79. None of the sample had an Adaptive Behavior Composite (ABC) score of 69 or less, although 15% scored between 70 and 79 on this measure. While none of the sample could be classified as having an ID in strict diagnostic terms, 4% scored 69 or below on the KBIT2 and in the borderline (71–79) range on the VABS2, 4% had borderline ABCs and IQs between 70 and 74; and 3% had borderline ABCs and IQs less than 79. This equates to a point prevalence of borderline ID of 11%.
Conclusions   Eleven per cent of the sample had borderline ID, supporting suggestions that this group are prevalent – and easily hidden – in mainstream criminal justice settings. Differences between borderline ID inmates and non-ID counterparts are discussed, and implications for service delivery are considered.     

Prevalence of people with intellectual disability in the Netherlands

Background Since the 1990s, people with intellectual disability (ID) in the Netherlands have been moving from institutions to supported accommodation in the community. The Government is in need of recent data on the numbers of these people, to ensure adequate care provision and funding. This paper reports on the prevalence of people with ID in the Netherlands. The research question was: what is the lowest and highest estimation of prevalence of people with ID in the Netherlands? Methods Two extrapolation methods were used, each consisting of a number of stages, using general practice databases and ID care services records. Results The prevalence of people with ID in the Netherlands was 0.7% (111 750 persons). Other assumptions yielded 0.54–0.64%. Arguments for the two extrapolation methods and the lowest and highest estimation of prevalence are discussed. Conclusions Compared with 1988, there has been a slight decrease in the prevalence of people with ID in the Netherlands, even though we included all age groups and even people with ID of who were not included in ID care services records. By using general practitioner databases it was possible to identify these not registered people with ID.     

The prevalence and nature of intellectual disability in Norwegian prisons

Background The objective of the study was to calculate the prevalence of inmates with intellectual disabilities (ID), and identify historical, medical and criminological characteristics of a certain impact. Methods A random sample of 143 inmates from a Norwegian prison cross sectional sample was studied. The Hayes Ability Screening Index (HASI) was validated with the Wechsler Abbreviated Scale of Intelligence (WASI). Results The prevalence of inmates with ID, IQ < 70, was 10.8%. Some essential characteristics of inmates with ID were more frequent medication for mental disorders, a higher number of imprisonments, less drug abuse and less education than the other inmates. The results indicated that the HASI is a valid tool for screening of ID for the Norwegian inmates. Conclusions The prevalence of ID in Norwegian inmates is significant, measured by WASI and HASI. Identification, rehabilitation and care, concerning an intellectual handicap, are mostly absent in the Norwegian criminal justice system.     

Children with intellectual disability in rural South Africa: prevalence and associated disability

Background The objective of the present study was to determine the prevalence of intellectual disability (ID) and its associated disabilities in rural South African children aged 2–9 years. It was undertaken in eight villages in the district of Bushbuckridge, Northern Province, South Africa. Methods A two‐phase design was utilized. The first phase involved screening children on a house‐to‐house basis by interviewing mothers or caregivers using an internationally validated questionnaire for detecting childhood disability in developing countries. The second phase consisted of a paediatric/neurodevelopmental assessment of the children who screened positive. Results A total of 6692 children were screened; 722 (10.8%) had a paediatric evaluation and 238 children were diagnosed with ID, giving a minimum observed prevalence of 35.6 per 1000 children in this population. The prevalence of severe and mild ID was 0.64 per 1000 and 29.1 per 1000 children, respectively. The male:female ratio of children with ID was 3:2. In the affected children, a congenital aetiology for the ID was determined in 49 subjects (20.6%), an acquired aetiology in 15 (6.3%) and the aetiology was undetermined in 174 children (73.1%). Epilepsy (15.5%) and cerebral palsy (8.4%) were the commonest associated disabilities. Conclusion The present study represents the first data on the prevalence of ID and associated disabilities in rural South African children. The prevalence of ID was comparable with results from a study performed in one other African country (Zambia) as well as those from other developing countries. The data provide an initial factual insight into ID and its associated disabilities for healthcare, social service and educational policy planners. This study provides a basis for the initiation and development of appropriate and integrated services for the best possible care of individuals affected with these disabilities, and for their possible prevention.     

Sexuality and personal relationships for people with an intellectual disability. Part I: service-user perspectives

Background   Despite a recent ideological shift towards the recognition of sexual autonomy for people with an intellectual disability (ID), there are continuing social and cultural barriers to sexual expression. Part I of the current two-part study assessed the sexual knowledge, experiences and aspirations of service users through focus groups and also examined their perceptions of impediments to achieving sexual autonomy.
Method   Thirty-two participants (20 male, 12 female) attending an ID service participated in focus groups delineated by gender and age group (13–17 years; 18–30 years; 31+ years).
Results   Analysis of the focus groups showed that service users, especially those over the age of 18 years, had an understanding of their sexual rights but also identified a number of social and cultural barriers that they felt prevent them from achieving sexual autonomy. Those under the age of 18 years had only rudimentary knowledge of sexuality issues, for example pregnancy and sexual anatomy, but aspired to relationships and marriage similar to those over the age of 18 years. Family and staff attitudes appeared to be very influential in the views of respondents. All service users had received some form of sex education, although the benefits of such education appeared most enduring for those over 18 years.
Conclusion   Service users had an understanding of their sexual rights and the social and environmental barriers that prevent them from fulfilling their rights. The provision of sex education training and promotion of positive attitudes towards appropriate sexual expression is critical to the realization of sexual autonomy for people with an ID.     

The use of social media and people with intellectual disability: A systematic review and thematic analysis

Background In this paper we present a systematic review of the evidence on the use of social media by people with intellectual disability.

Method Ten primary studies published in the English language between January 2000 and June 2014 were identified from electronic database searches (CINAHL, PsychInfo, PubMed, Web of Knowledge, and Scopus), correspondence with experts, and citation tracking.

Results Nine themes were identified through thematic analysis of the texts: “safety and safeguarding,” “social identity,” “level of usage,” “support,” “relationships,” “happiness and enjoyment,” “communication and literacy skills,” “cyber-language and cyber-etiquette,” and “accessibility/design”.

Conclusion Examination of these themes revealed that some people with intellectual disability are having positive experiences using social media in terms of friendships, development of social identity and self-esteem, and enjoyment. However, barriers that stop people with intellectual disability from successfully accessing social media were identified as being safeguarding concerns, difficulties caused by literacy and communication skills, cyber-language, cyber-etiquette, and accessibility (including lack of appropriate equipment).     

Autonomy in relation to health among people with intellectual disability: a literature review

Background Since the 1990s, individualisation, participation, normalisation and inclusion have been the main principles of care for people with intellectual disability (ID). Autonomy has become an important issue for these people. This review of the literature tried to answer the question: how do people with ID exercise autonomy in relation to health? Method Searches in Cochrane, Medline and PsycINFO were based on the following aspects of autonomy: self‐determination, independence, self‐regulation and self‐realisation. Results Thirty‐nine of 791 articles met our criteria, including 14 on self‐determination, seven on independence, 15 on self‐regulation and three on self‐realisation. Conclusions In spite of decades of promoting autonomy, the exercise of autonomy in relation to health has so far rarely been an issue in the literature.     

Community participation of people with an intellectual disability: a review of empirical findings

Study design A systematic review of the literature. Objectives To investigate community participation of persons with an intellectual disability (ID) as reported in empirical research studies. Method A systematic literature search was conducted for the period of 1996–2006 on PubMed, CINAHL and PSYCINFO. Search terms were derived from the International Classification of Functioning, Disability and Health. Three investigators assessed the relevance of the initially identified studies using predefined content and methodological selection criteria. Included domains of community participation were: (1) domestic life; (2) interpersonal interactions and relationships; (3) major life areas; and (4) community, civic and social life. Results Of 2936 initial hits, 23 quantitative studies eventually met the selection criteria and were included in the study. Only two studies are based on a theoretical framework. Research instruments were various and were most often ad hoc and not validated. The average number of persons in the social network of people with ID appears to be 3.1, one of them usually being a professional service staff member. People with ID are 3–4 times less employed than non‐disabled peers; they are less likely to be employed competitively and are more likely to work in sheltered workshops or in segregated settings than those with other disabilities. People with ID are less likely to be involved in community groups, and leisure activities are mostly solitary and passive in nature. Most of the people with ID had been accompanied in an activity by training/therapeutic staff. Conclusion It can be concluded that on the basis of empirical evidence, within the time frame of this literature search, little is known about community participation of people with ID. Many researchers did not clearly define community participation and were concerned with limited areas of community participation; research is seldom based on a theoretical framework. Most studies focus on people with mild ID, and there are few reports of the subjects' sample. However, one conclusion can consistently be drawn from the review: people with ID living in community settings participate more than people living in a segregated setting, but their participation level is still much lower than non‐disabled and other disability groups.     

Offenders with intellectual disability: a prospective comparative study

BACKGROUND: Intellectually disabled offenders (IDO) are a poorly served and under-recognized group, who are likely to require long-term specialist treatments and interventions. METHOD: This prospective study investigated the characteristics and factors that influence outcome in this group, with particular reference to therapeutic interventions. Sixty-one individuals were identified from contact with either (1) specialist health and social services for people with intellectual disability (ID) or (2) nonspecialist services in the criminal justice or (forensic) mental health/social service systems. The participants were assessed at baseline and after a mean of 10 months in order to compare recidivism rates and the impact of therapeutic interventions. RESULTS: The findings suggest that IDO start offending at an early age, that they frequently have a history of multiple offences, and that sex offending and arson are over-represented offence types. Those participants recruited from nonspecialist ID services had significantly higher IQs and were less likely to have had contact with community social and health support agencies. Despite the high rates of psychopathology, there was little evidence for efficacy of therapeutic interventions, which, where offered, appeared to be of a nonspecific nature. At second interview, approximately half of the sample had re-offended.     

Prevalence and incidence of health problems in people with intellectual disability

The objective of this study was to determine the prevalence and incidence of the most frequent chronic health problems in relation to age in people with intellectual disabilities living in residential facilities in the Netherlands. A prospective cohort study was done with four data collections, each with an interval of one year. Data were collected by means of questionnaires which were completed by each person's physician. Striking results included the reported high prevalence and incidence of visual and hearing impairment, which was even more pronounced in people with Down's syndrome than in people with intellectual disability resulting from other causes. Gastrointestinal problems also appeared to have high incidence rates. Dementia was frequently reported in people with Down's syndrome aged 40 years and older. The results reflect the need for a more predictive policy which can anticipate health problems in people with intellectual disability.     

Ethnic factors in mental health service utilisation among people with intellectual disability in high-income countries: systematic review

Background An emerging literature suggests that ethnic and cultural factors influence service utilisation among people with intellectual disability (ID), but this has not previously been reviewed. Aims To investigate possible ethnic variation in uptake of mental health services in children, adolescents and adults with ID in high‐income countries. Method A systematic review using main databases of studies that consider ethnic influences on mental health utilisation of people with ID. Methodological quality of studies was assessed. Results Nine studies that reached selection criteria were identified. Six studies that compared two or more ethnic groups found a variation in levels of mental health service utilisation. The most consistent finding was that South Asian children, adolescents and adults with ID in the UK had lower use of mental health services than White British comparison groups. Conclusion Ethnic influences on mental health service utilisation were identified. Understanding their significance and potential negative consequences requires further investigation.     

Careers of offenders with an intellectual disability: the probabilities of rearrest

Background This paper reports results from a total population of persons with intellectual disabilities (ID) in Western Australia arrested for the first time since 1 April 1984. It is part of a longitudinal study that ‘tracked’ offenders with ID through the criminal justice system over an 11-year period to compare their experiences at each stage of the justice process with a sample of the general offending population. The research draws on an analysis of the Western Australian Police Services Apprehension records and the Disability Services Commission database. Method The data collected provided the opportunity to calculate base rates of the probability of rearrest of offenders with ID in comparison to mainstream offenders. Results The study found that people with ID had a significantly higher rate of rearrest than general population offenders and the study canvasses some possible reasons for this finding.     

Alcohol and its relationship to offence variables in a cohort of offenders with intellectual disability

Abstract

Background Alcohol use and misuse may be lower in people with intellectual disability (ID) than in the general population but may be related to offending.

Method Alcohol-related crime and history of alcohol use was recorded in 477 participants with ID referred to forensic ID services and related to offending.

Results Level of alcohol-related crime and history of alcohol misuse was lower than in some previous studies at 5.9% and 20.8%, respectively. History of alcohol abuse was associated with alcohol-related offences and theft. Higher rates of alcohol problem history were associated with histories of a number of offences, psychiatric disturbance in adulthood, psychiatric disturbance in childhood, and experiences of childhood adversity. Most effect sizes were weak or moderate.

Conclusions The convergence of childhood adversity, psychiatric problems in childhood and adulthood, and alcohol abuse is consistent with studies that have found these as risk markers for offending.     

Police encounters with people with intellectual disability: prevalence, characteristics and challenges

Background This study investigated the experiences and perceptions of operational members of Victoria Police in relation to their contacts with people with intellectual disability (ID). Key interests for exploration included how frequently and in what context police reported coming into contact with people with ID, how they made this identification, and the challenges they experienced at this interface. Methods Participants comprised 229 operational police members who attended mandatory firearms training sessions over a 2‐week period in Melbourne, Australia. Results Police reported coming into contact with people they believed to have an ID on a regular basis and for a wide variety of reasons. They were most likely to base their knowledge on job‐related experiences and were most likely to identify individuals on the basis of physical and behavioural cues. The most common challenges were communication, and gaining access to assistance and co‐operation from other service providers. While many considered themselves capable in their interactions with those with ID, those who identified that they were most in need of training reported lower confidence in how to respond in these encounters. Conclusions Future training needs to focus on differentiating between mental illness and ID, techniques for enhancing identification and communication, and the inclusion of hands‐on scenario‐based sessions involving an interdisciplinary approach.