A review of the assessment and treatment of anger and aggression in offenders with intellectual disability

Cognitive behavioural anger treatment for adults with intellectual disabilities: effects of therapist experience on outcome

BACKGROUND

Anger has been shown to be associated with aggression and violence in adults with intellectual disabilities in both community and secure settings. Emerging evidence has indicated that cognitive behavioural anger treatment can be effective in reducing assessed levels of anger and violent behaviour in these patient populations. However, it has been suggested that the effectiveness of these types of interventions is influenced by the experience and training of the therapists.

METHOD

In this service evaluation study, the pre- and post-treatment and 12-month follow-up assessment scores of 88 detained in-patient adults with intellectual disabilities and forensic histories who received cognitive behavioural anger treatment were examined in order to investigate whether participants' responsiveness to treatment was associated with treatment being delivered by qualified versus unqualified therapists.

RESULTS

Overall significant reductions in self-reported measures of anger disposition and anger reactivity were found with no significant time × therapist experience interaction effects. However, the patients treated by qualified therapists improved significantly on measures of anger control compared with those allocated to unqualified therapists.

CONCLUSIONS

Male and female detained patients with intellectual disabilities and forensic histories can benefit from an individual cognitive behavioural anger treatment intervention delivered by qualified and unqualified therapists, but therapist experience may be important in supporting patients to develop more complex anger control coping skills.

Use of music for mood regulation in adolescents with intellectual disabilities: a case control study

Functions connected to mood and emotion regulation are often reported as the most frequent and important functions of music, particularly during adolescence. However, less is known on how adolescents with intellectual disabilities (ID) use music for emotion regulation. The aim of this study was therefore to explore how adolescents with intellectual disabilities (n = 30) use music for mood regulation in comparison to adolescents without ID (n = 34). We assessed the seven mood-regulation strategies of the Music in Mood Regulation questionnaire, personality traits, mood, and a number of variables regarding music listening. The result showed that personality and mood were associated with the use of music for mood regulation and that adolescents with ID were less specific in their use of mood regulation strategies than adolescents without intellectual disabilities, even when adjusting for gender differences. In conclusion, the present study shows that personality traits in addition to mood is related to differences in usage of music for mood regulation among adolescents with and without intellectual disability. The study provides initial insights into the use of music and the relationships between personality, mood, and music in mood regulation in adolescents with intellectual disabilities.

Emotion regulation and angry mood among adolescents with externalizing problems and intellectual disabilities

BACKGROUND AND AIMS

Cognitive behavior therapy targeting emotion regulation is found to be effective in decreasing externalizing problems, but little is known about the emotion regulation capacities of adolescents with externalizing problems and Mild Intellectual Disabilities or Borderline Intellectual Functioning (MID-BIF). Therefore, the aim of this study was to compare emotion (i.e., anger) regulation capacities, angry mood level and angry mood variability between two groups: adolescents with externalizing problems and MID-BIF and adolescents with externalizing problems and average intelligence (AIQ).

METHODS AND PROCEDURES

Participants in the MID-BIF (n = 42, M_age = 15.52, SD = 1.43) and AIQ (n = 39, M_age = 13.67, SD = 1.06) group completed questionnaires about emotion regulation difficulties, emotion regulation strategies, and angry mood.

OUTCOMES AND RESULTS

Adolescents in the MID-BIF group reported fewer emotion regulation difficulties, fewer maladaptive regulation strategies, and lower levels of angry mood than adolescents in the AIQ group. No between-group differences in angry mood variability were found. Lastly, adolescents in the MID-BIF group reported to use more behavioral than cognitive regulation strategies.

CONCLUSIONS AND IMPLICATIONS

These findings provide a starting point in understanding emotion regulation and angry mood of adolescents with externalizing problems and MID-BIF and show that it is important to consider differences between cognitive and behavioral regulation processes.

Social Cognition in Children With Non-specific Intellectual Disabilities: An Exploratory Study

Social cognitive abilities - notably, Theory of Mind (ToM) and social information processing (SIP) - are key skills for the development of social competence and adjustment. By understanding affective and cognitive mental states and processing social information correctly, children will be able to enact prosocial behaviors, to interact with peers and adults adaptively, and to be socially included. As social adjustment and inclusion are major issues for children with intellectual disabilities (IDs), the present study aimed to explore their social cognitive profile by combining cluster analysis of both ToM and SIP competence, and to investigate the structure of relations between these skills in children with IDs. Seventy-eight elementary school children with non-specific IDs were recruited. They had a chronological age ranging from 4 years and 8 months to 12 years and 6 months and presented a preschool developmental age. Performance-based measures were administered to assess ToM and SIP abilities. Questionnaires were completed by the children's parents to evaluate the children's social competence and adjustment and their risk of developing externalizing or internalizing behaviors. Exploratory analysis highlighted strengths and weaknesses in the social cognitive profiles of these children with IDs. It also emphasized that the understanding of affective and cognitive mental states was used differently when facing appropriate vs. inappropriate social behaviors. The present study leads to a better understanding of the socio-emotional profile of children with IDs and offers some suggestions on how to implement effective interventions.

The reliability and validity of the Adaptive Functioning Assessment Tool in UK custodial settings

Adaptive functioning (AF) has been overlooked in the assessment of intellectual disability within the UK Prison Service, primarily because there are no reliable and valid measures of AF suitable for use with prison populations. This position is incompatible with the obligation of Her Majesty's Prison and Probation Service to provide specialist interventions for individuals with intellectual disabilities. This study assessed the psychometric properties of the Adaptive Functioning Assessment Tool (AFAT), a new measure of AF developed for use in prisons. The AFAT was completed on 61 participants (mean age 41, standard deviation 11.8). Internal consistency was tested using Cronbach's α. Construct validity was assessed using linear regression and a Receiver Operator Characteristic analysis. The findings provide evidence to support the AFAT being a reliable and valid measure of AF in prison populations.

The Prevalence and Correlates of Partner Violence Used and Experienced by Adults With Intellectual Disabilities: A Systematic Review and Call to Action

It has been suggested that individuals with intellectual disabilities (IDs) are at increased risk of violence perpetration and victimization. A systematic review was undertaken to identify and critically evaluate the existing empirical research concerning the use and experience of partner violence by adults with IDs. In total, six poor-quality articles were identified: five of which adopted qualitative methods and one of which adopted a mixed-methods approach, comprising a total of 93 participants (48 women, 45 men: 1 perpetrator, 92 victims). The qualitative data were extracted from the studies and synthesized. A partner violence victimization rate of 60% was identified in one nonrepresentative sample. Two superordinate themes emerged from the qualitative data: nature of partner violence experience and help seeking. Children were the cross-cutting theme within the two superordinate themes. Participants reported experiencing a range of physical, emotional, and sexual violence leading to serious injury and psychological consequences. Participants reported experiences of positive and negative help-seeking reactions from professionals and specific requirements of services for victims with IDs. Children were identified as involved in the experience of abuse, the impact of abuse, and decisions to seek help. The findings indicate that training of clinical staff to detect partner violence is needed. In addition, adults with IDs need education concerning healthy relationships. Research is needed to better understand the difference between "challenging behavior" that is behavior displayed by an individual which challenges services, family members, and carers. Such behavior is more common in individuals with a severe ID for whom it would not be appropriate to be dealt with through the criminal justice system, and partner violence, in order to develop appropriate interventions for victims and perpetrators with ID.

Using a Videogame Intervention to Reduce Anxiety and Externalizing Problems among Youths in Residential Care: an Initial Randomized Controlled Trial

Residential care is among the most intensive forms of treatment in youth care. It serves youths with severe behavioral problems and is primarily focused on targeting externalizing problems. Despite best efforts, effect sizes remain moderate, which may be due to the disregarding of internalizing symptoms - in particular anxiety - and to limitations regarding the delivery model of interventions. This initial randomized controlled trial (n = 37) aimed to examine the effectiveness of a biofeedback videogame intervention (Dojo) as an addition to treatment as usual for youths with and without intellectual disability (ID) in residential care with clinical levels of anxiety and externalizing problems. Dojo targets both anxiety and externalizing problems, and incorporates the principles of conventional treatment, while addressing its limitations. Youths were randomly assigned to play Dojo (eight 30-min gameplay sessions) or to treatment as usual (TAU). Measurements of anxiety and externalizing problems were conducted at baseline, posttreatment, and 4-months follow-up through youths' self-report and mentor-report. Completers-only analyses revealed decreases in self-reported anxiety and externalizing problems, and mentor-reported anxiety at posttreatment for participants in the Dojo condition compared to the control condition. Only mentor-reported anxiety was maintained at follow-up. No effect was found for mentor-reported externalizing problems. These findings provided preliminary evidence that Dojo is a promising, innovative intervention that engages high-risk youths. Practical implications are discussed.

Usability evaluation of the digital anger thermometer app

The digital anger thermometer is a prototype for a mobile application (app) for use with adults in anger management treatment. The digital anger thermometer incorporates standards of software development in addition to anger management resources from the Substance Abuse and Mental Health Services Administration. The digital anger thermometer underwent a usability study conducted by five expert reviewers. The results indicate that it is easy to learn, efficient, and ergonomically sound. However, it does not offer support features or user-error tolerance. The digital anger thermometer prototype requires additional usability studies and comparative research in order for it to become an actual mental health app.

Reductions in aggression and violence following cognitive behavioural anger treatment for detained patients with intellectual disabilities

BACKGROUND

Aggression is a significant problem amongst people with intellectual disabilities (ID), particularly those residing in hospital settings. Anger is related to aggression in secure services working people with ID, and the effectiveness of psychological interventions in reducing anger has been demonstrated in this population. However, no studies have systematically examined whether levels of aggression reduce following anger treatment with people with ID detained in secure settings.

METHOD

This programme evaluation study concerns individually delivered cognitive anger treatment delivered to 50 patients (44 men and 6 women) with mild to borderline ID, delivered twice weekly for 18 sessions in a specialist forensic hospital service. Aggressive incidents and physical assault data were obtained from records 12 months pre-treatment and 12 months post-treatment.

RESULTS

Following completion of treatment, the total number of aggressive incidents recorded in patients' files fell by 34.5%, and the post-treatment reduction in the number of physical assaults was 55.9%. Analysis of the data partitioned into 6-month blocks over the 24-month study period showed that significant reductions in aggressive and violent incidents occurred in the assessment intervals following anger treatment.

CONCLUSIONS

These findings reinforce the efficacy of cognitive behavioural anger treatment for detained patients with ID and histories of aggression; and despite its methodical limitations the study indicates the ecological validity of this treatment approach.

Social networks of people with mild intellectual disabilities: characteristics, satisfaction, wishes and quality of life

BACKGROUND

A supportive social network is crucial for facilitating social inclusion, which can, in turn, contribute to the quality of life (QOL) for people with intellectual disabilities (ID). In this study, we investigate how people with mild ID perceive their social networks and which network characteristics relate to satisfaction with the network and perceived QOL.

METHOD

Data were gathered from 33 young adults with a mild to borderline ID using structured questionnaires: the MSNA to map the social network, the IDQOL-16 to assess QOL, and a questionnaire to determine satisfaction and wishes with regard to the social network.

RESULTS

The majority of the participants (73.1%) were satisfied with their social networks. Improvement in the area of strengthening existing ties (e.g. more frequent contact, better contact) was desired as opposed to expansion of the network. Affection--especially towards family and professionals--was most strongly related to perceived QOL. It appears to be essential that relatives live in the same town, can frequently meet up and provide both emotional and practical support.

CONCLUSIONS

The significance of family and the importance of high-quality interpersonal relationships between professional and client in the lives of young adults with ID cannot be overestimated. Although measures of satisfaction and wishes can have limitations, in actual practice it is considered useful to assess the opinions of clients with respect to their social networks. Interventions can then be tailored to the needs and wishes of the persons themselves.

A multilevel meta-analysis of single-case and small-n research on interventions for reducing challenging behavior in persons with intellectual disabilities

The effectiveness of different interventions for challenging behavior (CB) in persons with intellectual disabilities (ID) was reviewed by means of a two-phase study. First, a systematic review of 137 meta-analyses and reviews on group-study interventions for CB in persons with ID was conducted. Based on this review, hypotheses concerning the effectiveness of divergent interventions for CB and concerning the impact of variables moderating treatment effectiveness were systematically generated. Second, these hypotheses were tested by means of a multilevel meta-analysis of single-case and small-n research. Two hundred and eighty-five studies reporting on 598 individuals were examined. The average treatment effect was large and statistically significant. However, this effect varied significantly over the included studies and participants. Compared to the meta-analyses and reviews focusing on group-studies in this research domain, the results of the present multilevel meta-analysis of single-case and small-n intervention research provided more detailed knowledge on which specific CB and intervention components moderate the interventions' effectiveness.

Peer with intellectual disabilities as a mindfulness-based anger and aggression management therapist

A young man with intellectual disabilities (ID) and mental illness, who had previously been taught to successfully manage his aggressive behavior by using Meditation on the Soles of the Feet, reported that he shared his mindfulness practice with his peers with ID. When requested by his peers, and without any training as a therapist, he began to teach this procedure to his peers for controlling their anger and aggressive behavior. We tracked the anger and aggressive behavior of three of the individuals he taught and the fidelity of his teaching of the procedure. According to self and staff reports, anger and aggressive behavior of the three individuals decreased to very low levels within five months of initiating training and remained at very low levels for the two years during which informal data were collected. The fidelity of his teaching the procedure was high, if one allows for his idiosyncratic teaching methods. These findings suggest that individuals with mild ID, who have mastered an effective mindfulness-based strategy to control their aggressive behavior, may be able to teach their peers the same strategy to successfully control their anger and aggressive behavior to a level that is acceptable for community living.

Factors associated with the efficacy of a group intervention for anger in people with intellectual disabilities

OBJECTIVES

There is a growing literature that suggests cognitive behavioural interventions aimed at reducing inappropriately expressed anger by people with intellectual disabilities are effective. However, interventions provide little information about which aspects of the individual or their treatment may be contributing to the overall efficacy of the approach.

DESIGN

A group intervention is compared with a waiting list control. A cross-sectional regressional method was used to explore the relationship between change in a provocation inventory score over the course of an intervention and a number of other variables.

METHODS

Data was collected from 50 participants who attended a series of groups with the aim of reducing aggressive behaviour. This was compared with a waiting list control of 36. Outcome was measured by a provocation inventory, which was administered pre-, post-group, and at follow-up. Other variables were also measured including, receptive vocabulary, age, gender, experience of primary therapist and whether staff accompanied participants to the group or not.

RESULTS

A 2 x 2 split plot ANOVA identified a statistically significant treatment effect. However, analysis examining clinical significance was more equivocal with only 11 of the individuals in the intervention group showing reliable change as defined by Jacobson and Truax (1991). Regression analysis indicated that 17.5% of the variance in change of provocation inventory scores could be accounted for by the independent variables. Immediately on completion of the group, being accompanied by a member of staff and increased receptive language scores contributed significantly to the variance.

CONCLUSIONS

A reduction in provocation inventory scores immediately after the group was more likely to occur if the participant was accompanied by a member of staff who knew them and if they had a higher score on the test of receptive vocabulary. This pattern changed with time. The implications of the results will be discussed and the relatively large amount of variance that is not accounted for will also be considered.

Individual cognitive-behavioural anger treatment for people with mild-borderline intellectual disabilities and histories of aggression: A controlled trial

OBJECTIVES

Anger is a significant predictor and activator of violent behaviour in patients living in institutional settings. There is some evidence for the value of cognitive-behavioural treatments for anger problems with people with intellectual disabilities. In this study, a newly designed treatment targeted at anger disposition, reactivity, and control was provided to intellectually disabled offenders with aggression histories living in secure settings.

DESIGN

About forty detained patients with mild-borderline intellectual disabilities and histories of serious aggression were allocated to specially modified cognitive-behavioural anger treatment (AT group) or to routine care waiting-list control (RC group) conditions.

METHODS

AT group participants received 18 sessions of individual treatment. The AT and RC groups were assessed simultaneously at 4 time points: screen, pre- and post-treatment, and at 4-month follow-up using a range of self- and staff-rated anger measures. The effectiveness of the treatment was evaluated using ANCOVA linear trend analyses of group differences on the main outcome measures.

RESULTS

The AT group's self-reported anger scores on a number of measures were significantly lower following treatment, compared with the RC wait-list condition, and these improvements were maintained at follow-up. Limited evidence for the effectiveness of treatment was provided by staffs' ratings of patient behaviour post-treatment.

CONCLUSIONS

Detained men with mild-moderate intellectual disabilities and histories of severe aggression can successfully engage in, and benefit from, an intensive individual cognitive-behavioural anger treatment that also appears to have beneficial systemic effects.

Carer reports of the efficacy of cognitive behavioral interventions for anger

Anger resulting in Aggression can be a significant problem for some people with Intellectual Disabilities. Carers were asked to complete a provocation inventory and an attribution scale before and after a group cognitive behavioral intervention aimed for anger and at similar points in time for a waiting list control. When compared using an analysis of variance results suggest that staff perceive a significant reduction in aggressive responses for participants who took part in the intervention. A regression analysis of factors that may influence the amount of change observed suggests that greater change was achieved if participants were accompanied by carers and had been attributed by carers as having an emotional cause for their behavior.

A meta-analysis of intervention effects on challenging behaviour among persons with intellectual disabilities

BACKGROUND

Persons with intellectual disabilities (ID) often show challenging behaviour. We review distinct interventions that are applied to treat these challenging behaviours, and analyse intervention effects and moderating variables.

METHODS

A literature search was conducted using the databases ERIC, PsycINFO, Web of Science and Medline. A random-effects meta-analysis was carried out, supplemented with sensitivity, subgroup, meta-regression and publication bias analyses.

RESULTS

Eighty potential articles were identified, from which 30 contained sufficient data to enable statistical meta-analysis. From these 30 studies, 18 described a biological, 13 a psychotherapeutic and nine a contextual intervention, either applied alone or combined. The overall standardised mean difference was 0.671 (SD = 0.051). As shown by sensitivity analysis, this summary effect size is robust. Assessed through subgroup and meta-regression analysis, all tested moderators showed no statistically significant association with the treatment effects. After applying a funnel plot-, a fail-safe N-, and Duval's and Tweedie's trim and fill-analysis, we conclude that our meta-analysis does not suffer much from publication bias effects.

CONCLUSIONS

Several biological, psychotherapeutic and contextual interventions effectively reduce challenging behaviours among persons with ID.

Cognitive behavioural therapy: from face to face interaction to a broader contextual understanding of change

Cognitive behavioural therapy (CBT) is increasingly used to address the emotional and interpersonal problems of people with ID. There is a limited but promising evidence base supporting this activity. However, these individuals face real and continuing challenges in their lives that have implications for their self and interpersonal perceptions. These adversities have implications for the adaptation of CBT. First, it may mean that characteristically negative perceptions may be more common and may be the result of a complex interaction with a truly aversive environment and should not simply be considered as cognitive distortions. Secondly, clients may have limited control over their everyday lives, with limited opportunity to negotiate change with their informal and formal sources of support. This review suggests that it is important to consider the interpersonal context of therapy both to ensure effective work within sessions and to enable real change in clients' everyday lives. The review draws upon Vygotsky's theory of the zone of proximal development and ecological models of change to consider the challenges of establishing collaborative relationships and the potential to use CBT within a broad psychosocial model. The aim is to offer a helpful framework for practitioners and to identify directions for future research.

Assessing anger in people with intellectual disability

BACKGROUND

There is a growing interest in the use of cognitive approaches for the treatment of psychological difficulties with people who have intellectual disability. The aim of the present study was to investigate the properties of an anger inventory, the relationship between self-reported and staff-reported levels of anger, and the relationship between different staff measures.

METHOD

Two studies are described that use self-report and staff-report measures. The first study employs a cross sectional design and the second, a longitudinal design.

RESULTS

No relationship was found between self-reported and staff-reported levels of anger on the first measurement occasion, but on the second measurement occasion after some intervention a significant relationship was found. If staff had accompanied individuals during an intervention a larger correlation was found.

CONCLUSION

These results suggest that staff may require specific training or exposure to a therapeutic environment before they can predict the response of people with intellectual disability on the anger inventory. This suggests that involvement of care staff in interventions may be useful therapeutically.

Depression in adults with mild intellectual disability: role of stress, attributions, and coping

The experience of stressful social interactions, negative causal attributions, and the use of maladaptive coping efforts help maintain depression over time in the general population. We investigated whether a similar experience occurs among adults with mild intellectual disability. We compared the frequency and stress impact of such interactions, identified causal attributions for these interactions, and determined the coping strategies of 47 depressed and 47 nondepressed adults with mild intellectual disability matched on subject characteristics. The depressed group reported a higher frequency and stress impact of stressful social interactions, more negative attribution style, and more avoidant and less active coping strategies did than the nondepressed group. Findings have implications for theory building and development of psychotherapies to treat depression.

Contextual variables affecting aggressive behaviour in individuals with mild to borderline intellectual disabilities who live in a residential facility

BACKGROUND

Aggression is a common type of problem behaviour in clients with mild to borderline intellectual disability who live in a residential facility. We explored contextual events that elicit aggressive behaviour and variables that were associated with such events.

METHOD

Respondents were 87 direct-care staff members of 87 clients with aggressive behaviour who lived in a residential facility. Staff members completed the Contextual Assessment Inventory (CAI) and a questionnaire on demographic information and types, frequency and severity of aggressive behaviour. Internal consistency of the total CAI was excellent (alpha = 0.95), and Cronbach alpha's for the CAI sub-scales ranged from 0.75 to 0.93. Inter-rater agreement for the CAI could be considered good (mean intra-class correlation coefficient = 0.63).

RESULTS

Both social and task-related events were reported to evoke aggressive behaviour of clients most often. Negative interactions, task characteristics and daily routines relatively often evoked aggressive behaviour while an uncomfortable environment, medication, illness and physiological states (i.e. physical and biological events) evoked aggressive behaviour least often. Mean CAI sub-scale scores were significantly related to gender, IQ and frequency of aggressive behaviour.

CONCLUSION

The present study extends our knowledge regarding events that are associated with an increased probability of aggressive behaviour. Knowledge of these contextual variables may be helpful in designing programmes (e.g. applied behaviour analysis, social skills training and cognitive behavioural therapies) for the management and prevention of aggressive behaviour in clients with mild to borderline intellectual disability who live in a residential facility.

CBT for People with Intellectual Disabilities: Emerging Evidence, Cognitive Ability and IQ Effects

Historically people with intellectual disabilities have not been offered or received cognitive behavioural interventions that have been shown to be effective for mental health and emotional problems experienced by those without such disabilities. This is despite many people with intellectual disabilities having life experiences that potentially result in them having an increased risk to such problems. This paper discusses whether such therapeutic disdain is justified based on the evidence that is available and emerging concerning the application of cognitive behavioural interventions for this population. Issues concerning access to services, the ability of people with intellectual disabilities to engage in and benefit from the cognitive components of CBT, and the effect of cognitive abilities and IQ level on treatment effectiveness are explored in relation to this question.

Diagnosis and treatment of aggression in individuals with developmental disabilities

Aggressive behavior is a common referral problem for individuals with developmental disabilities (DD), placing them at risk for institutionalization, social isolation, physical restraint, over-use of medication to treat behavior problems, exclusion from services, and becoming a victim of abuse. Aggression strains relationships between individuals being supported and their caregivers, whether professionals or family members. The treatment of aggression is persons with DD, with or without comorbid mental illness, remains a controversial area and changes in practice have been slow to come. The evidence related to pharmacotherapy and psychological treatment is, in general, either lacking or poor. This does not suggest that these treatments are necessarily ineffective but that there is not enough good quality evidence to support their usefulness. This review considers the prevalence and correlates of aggression, as well as possible causative factors. The relationship between mental illness, intellectual disability and aggression is explored. The psychopharmacological and psychological treatment literature is reviewed with implications for clinical care and future research.

Clinical and Benefit—Cost Outcomes of Teaching a Mindfulness-Based Procedure to Adult Offenders With Intellectual Disabilities

The effects of a mindfulness-based procedure, called Meditation on the Soles of the Feet, were evaluated as a cognitive-behavioral intervention for physical aggression in 6 offenders with mild intellectual disabilities. They were taught a simple meditation technique that required them to shift their attention and awareness from the precursors of aggression to the soles of their feet, a neutral point on their body. Results showed that physical and verbal aggression decreased substantially, no Stat medication or physical restraint was required, and there were no staff or peer injuries. Benefit—cost analysis of lost days of work and cost of medical and rehabilitation because of injury caused by these individuals in both the 12 months prior to and following mindfulness-based training showed a 95.7% reduction in costs. This study suggests that this procedure may be a clinically effective and cost-effective method of enabling adult offenders with intellectual disabilities to control their aggression.

Persons with intellectual disabilities in the criminal justice system: review of issues

Although the vast majority of individuals with intellectual disabilities (ID) are law-abiding citizens, there is a small percentage with offending behaviour that is considered antisocial, socially inappropriate, or defined as illegal. It has long been recognised that individuals with ID or mental-health needs who break the law should be dealt with differently from the general population. There have been an increasing number of empirical studies in this area; however, these have been plagued by various definitional and methodological issues. Prevalence estimates of offenders with ID are complicated by diagnostic variations and inconsistencies in the criminal justice process. International studies have shown a large range, from 2% to 40%, depending on methodological approaches. The following review will highlight the salient issues including prevalence of offending, characteristics of offenders, vulnerabilities within the legal system, assessment, and a brief overview of intervention and treatment approaches.

Exploratory factor analysis and convergent validity of the Dundee Provocation Inventory

Background The prevalence and consequences of anger and aggression in people with intellectual disability (ID) are of great concern. It is essential that appropriate assessment tools are developed to aid formulation of treatments and to evaluate progress and outcomes. Method This study evaluates the Dundee Provocation Inventory (DPI), a 20-item assessment measure for anger provocation. A group of 114 participants were administered the DPI, and 62 of these were also administered the Novaco Anger Scale (NAS) and NAS Provocation Inventory (NAS-PI), two well-validated measures. Results Preliminary analysis revealed that the DPI correlated significantly with the NAS (r = .57) and NAS-PI (r = .77). The DPI had high internal consistency (alpha = .91) and moderate to high inter-item and item-to-total score correlations. Factor analysis revealed a 5-factor solution which accounted for 63% of the variance and was most easily interpreted. Conclusion The analysis suggests that the DPI is a suitable tool for assessing anger in people with ID. Further replication of the factor structure would be valuable.

Trends and challenges in forensic research on offenders with intellectual disability

BACKGROUND

The Journal of Intellectual & Developmental Disability has a well-respected history of establishing the parameters and contributing to developments in the field of offenders with intellectual disability (ID).

METHOD

The field has seen a number of developments over the past 15 years, and this paper identifies several trends that have emerged in the research during this period, including work on prevalence of ID in prison populations, development of risk assessment, consideration of staff issues, developing the psychometrics of offence-specific assessments, evaluating treatment methods, and testing the underlying theoretical frameworks which attempt to account for offending.

RESULTS AND CONCLUSIONS

We refer to a number of studies which have advanced these developments in the field and draw the reader's attention to the way in which papers in this special issue contribute to and further develop each of these research trends.

Empathy and theory of mind in offenders with intellectual disability

BACKGROUND

Little research has been carried out on empathy and theory of mind in offenders with intellectual disability (ID) and these concepts are often poorly defined.

METHOD

Various models of empathy and theory of mind are discussed and scores on 2 empathy and 3 theory of mind tasks are compared for 25 offenders with ID and 25 non-offenders with ID (all male).

RESULTS

Differences were found in empathy and theory of mind performance of offenders and non-offenders with ID. Offenders performed better than non-offenders on a second order theory of mind task and on emotion recognition. They required fewer prompts to mention emotions, and gave empathic/caring responses more often than non-offenders when observing happiness (but not sadness or anger).

CONCLUSIONS

Results suggest that offenders with ID may have better, rather than poorer, empathy and theory of mind abilities than non-offenders, and that empathy training is therefore not indicated for this group.

A comparison of offenders with intellectual disability across three levels of security

BACKGROUND

A number of authors have described, with disparate results, the prevalence of people with intellectual disability and their characteristics, in a range of offender cohorts defined by service use. These have included high security, a range of criminal justice services and community services. There is a need for research comparing cohorts of offenders with intellectual disabilities across different settings. AIM AND HYPOTHESIS: To conduct such a comparison and test the hypothesis that severity of characteristics measured will be highest in highest levels of residential security.

METHOD

A clinical-record-based comparison a offenders with intellectual disability in high security (n = 73), medium/low security (n = 70), and a community service (n = 69).

RESULTS

Groups were similar in age and tested IQ levels. Early psychiatric service contact had been more likely in the lower security groups. In line with the hypothesis, more complex presentations, in particular comorbid personality disorder, was more likely in the highest security group. Both fatal and non-fatal interpersonal violence convictions were significantly related to group, with more in the high security group sustaining a conviction both at the index offence and prior to that. Over 50% of all groups had at least one conviction for a sexual offence. A regression model accounting for 78% of the variance was made up largely of disposal variables (Mental Health Act status and probation) and indications of antisocial traits (criminal damage, lifetime conviction for murder and ICD-10 personality disorder classification).

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

The authors show that context of sampling affects most relationships between intellectual disability (ID) and offending when the methods for measuring ID are held constant. The results also present several questions on the relationship between risk, services available in an area and referral to higher security.

Sexual and nonsexual offenders with intellectual and learning disabilities: a comparison of characteristics, referral patterns, and outcome

This article reports an evaluation of a community intellectual disability offender service over the period from 1990 to 2001. Men who committed sex offenses or sexually abusive incidents (n = 106) and men who committed other types of offenses and serious incidents (n = 78) are compared on personal characteristics, referral sources, forensic details, and outcome up to 7 years after referral. The cohorts are older than one would expect from the criminology literature, and, at about 33%, the incidence of mental illness is consistent with some previous studies. A greater proportion of sex offenders had criminal justice involvement and a formal disposal from court. Fire raising was not overly represented as an offense. There was a higher rate of reoffending in the nonsexual cohort, which persisted up to 7 years. Investigating only reoffenders, there was a considerable amount of harm reduction recorded up to 7 years, statistically significant up to 5 years following initial referral.

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.