Predicting aggression in adults with intellectual disability: A pilot study of the predictive efficacy of the Current Risk of Violence and the Short Dynamic Risk Scale.

BACKGROUND: Structured assessments have been shown to assist professionals to evaluate the risk of aggression in secure services for general offender populations and more recently among adults with intellectual disabilities. There is a need to develop intellectual disability sensitive measures for predicting risk of aggression in community samples, especially tools with a focus on dynamic variables. METHODS: The study prospectively followed 28 participants for up to 2 months to test whether the Current Risk of Violence (CuRV) and Short Dynamic Risk Scale (SDRS) were able to predict verbal and physical aggression in a community sample of adults with intellectual disability. RESULTS: CuRV and SDRS ratings significantly predicted verbal and physical aggression over a 2-month period. CONCLUSIONS: The current study supports the use of the CuRV with adults with intellectual disability living in community settings. The CuRV and SDRS are worthy of future development and evaluation in independent investigations.

The protective scale of the Armidilo-S: The importance of forensic and clinical outcomes.

BACKGROUND: The Armidilo has two scales-the risk scale and the protective scale. Research has been confined to the risk scale which appears to predict future incidents with medium to large effect sizes. There have been no publications on the use of the protective scale. METHODS: The Armidilo was completed on four individuals with IDD who were either moving on from their placement or whose placement was in jeopardy because of new information or altered policies in the organization. The Armidilo was completed in the usual fashion. RESULTS: Risk and protective results show that for each individual, recommendations could be made that ensured the best outcome. For two participants, restrictive placements were avoided because of the data on protective factors. CONCLSIONS: The protective scale can be a powerful support for the clinician's case in offenders with IDD. The protective scale should be completed routinely for clinical evaluation.

A systematic review and synthesis of outcome domains for use within forensic services for people with intellectual disabilities.

BACKGROUND: There is limited empirical information on service-level outcome domains and indicators for the large number of people with intellectual disabilities being treated in forensic psychiatric hospitals. AIMS: This study identified and developed the domains that should be used to measure treatment outcomes for this population. METHOD: A systematic review of the literature highlighted 60 studies which met eligibility criteria; they were synthesised using content analysis. The findings were refined within a consultation and consensus exercises with carers, patients and experts. RESULTS: The final framework encompassed three a priori superordinate domains: (a) effectiveness, (b) patient safety and (c) patient and carer experience. Within each of these, further sub-domains emerged from our systematic review and consultation exercises. These included severity of clinical symptoms, offending behaviours, reactive and restrictive interventions, quality of life and patient satisfaction. CONCLUSIONS: To index recovery, services need to measure treatment outcomes using this framework. DECLARATION OF INTEREST: None. COPYRIGHT AND USAGE: © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY) licence.

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

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.

Why do some people with intellectual disability engage in offending behaviour and what can we do about it? Editorial.

BACKGROUND: The field of forensic intellectual disabilities has been developing rapidly over the last 15 years. Much of the work has been built on research in mainstream criminality but more recently studies have emerged that reveal issues specific to offenders with intellectual disability. METHOD: Research on pathways into offending is reviewed with reference to its relevance to the field of intellectual disability. We also summarize some findings on pathways into and through services for offenders with intellectual disability. FINDINGS: Studies reveal that developmental adversity is an important risk variable. Previous and recent aggression are potent risk factors. New evidence suggests that immediate, proximal risk factors may be more important in this client group. The studies in this issue add to the knowledge on pathways into offending, important areas for assessment and effective treatments as well as advancing knowledge in the academic literature on general criminality.

Prospective dynamic assessment of risk of sexual reoffending in individuals with an intellectual disability and a history of sexual offending behaviour.

BACKGROUND: The purpose of the present study was to add to the literature on the predictive accuracy of a dynamic intellectual disability specific risk assessment tool. METHOD: A dynamic risk assessment for sexual reoffending (ARMIDILO-S), a static risk assessment for sexual offending (STATIC-99), and a static risk assessment for violence (Violence Risk Appraisal Guide [VRAG]) were completed for a sample of 64 adult males with an intellectual disability. RESULTS: The dynamic risk assessment for sexual offenders with an intellectual disability resulted in the best prediction of sexual reoffending (ARMIDILO-S area under the curve (AUC) = 0.92) this was better than an established sexual offending static risk assessment (STATIC-99 AUC = 0.75). A static tool for violent reoffending, did not perform as well in this group (VRAG AUC = 0.58). CONCLUSIONS: Results suggest that dynamic variables are useful in predicting sexual reoffending with individuals with an intellectual disability, confirming previous findings. The ARMIDILO-S is a promising dynamic risk assessment for individuals with an intellectual disability.

Face recognition and description abilities in people with mild intellectual disabilities.

BACKGROUND: People with intellectual disabilities (ID) are as likely as the general population to find themselves in the situation of having to identify and/or describe a perpetrator's face to the police. However, limited verbal and memory abilities in people with ID might prevent them to engage in standard police procedures. METHOD: Two experiments examined face recognition and description abilities in people with mild intellectual disabilities (mID) and compared their performance with that of people without ID. Experiment 1 used three old/new face recognition tasks. Experiment 2 consisted of two face description tasks, during which participants had to verbally describe faces from memory and with the target in view. RESULTS: Participants with mID performed significantly poorer on both recognition and recall tasks than control participants. However, their group performance was better than chance and they showed variability in performance depending on the measures introduced. CONCLUSIONS: The practical implications of these findings in forensic settings are discussed.

An evaluation and 20-year follow-up of a community forensic intellectual disability service.

BACKGROUND: Since the middle of the 20th century, there have been several heterogeneous studies of recidivism by offenders with intellectual disabilities (ID) who have been in specialist mental health services after an index offence. Although some were long term, as befits a chronically needy group, laws and services have changed in that time. It may no longer be appropriate to rely on findings from the 1960s and 1970s. AIMS: To compare mental health presentations and recidivism between male sex offenders, men convicted of other offences and female offenders from a 1986-2008 cohort of offenders referred to specialist forensic ID services in Scotland. METHOD: A 20-year follow-up of an assessment and treatment service for 309 offenders with ID (156 sex offenders, 126 non sexual male offenders and 27 women) was conducted. RESULTS: Sex offenders were more likely to be referred from the courts and had lower anger levels. Women were more likely to be diagnosed with mental illness. There was a split between groups with sex offenders committing few nonsexual offences and the other groups showing few sexual offences. During the study period, 16% of sexual offenders, 43% of male nonsexual offenders and 23% of women committed at least one further offence. Following assessment and treatment there was a 90-95% reduction in offending incidents. CONCLUSIONS: Although recidivism rates are disappointing, harm reduction data suggests that assessment and treatment for offenders with ID can be highly successful in terms of public safety.

Individuals with developmental delay and problematic sexual behaviors.

The field of sex offenders with intellectual and developmental disabilities (IDD) has attracted a significant amount of research in the last 5 to 10 years. This research has included theoretical work on the reasons why men with IDD might engage in problematic sexual behaviours, work on the assessment of risk for future incidents, research investigating the pathways into and through services for sex offenders with IDD and a considerable amount of work developing and evaluating effective treatments. This paper will review the recent research on each of these areas in turn.

The impact of known criminogenic factors on offenders with intellectual disability: previous findings and new results on ADHD.

BACKGROUND: Developmental and index offence variables have been implicated strongly in later criminal behaviour and service pathways and this paper investigated attention deficit hyperactivity disorder (ADHD) which, with conduct disorder, has emerged from previous studies on offenders. ADHD and conduct disorder are over-represented among criminal populations when compared to the general population. The present authors reviewed the extent to which ADHD affected the presentation of offenders with intellectual disability. METHOD: Information related to index behaviour, history of problem behaviours, childhood adversity and psychiatric diagnoses was recorded in 477 referrals to forensic intellectual disability services. Comparisons were made between those with a previous diagnosis of ADHD and those without. RESULTS: The ADHD group showed higher proportions of physical aggression, substance use, previous problems including aggression, sexual offences and property offences, birth problems and abuse in childhood. Effect sizes were small. CONCLUSION: Attention deficit hyperactivity disorder with conduct disorder is associated with a greater degree and history of problematic behaviour in offenders with intellectual disability.

People with intellectual disability who offend or are involved with the criminal justice system.

PURPOSE OF REVIEW: This review assesses the impact of recent research on the field of offenders with intellectual disabilities. Research includes work on prevalence, developments in appropriate assessments and investigations into the effectiveness of treatment procedures. RECENT FINDINGS: Methodological difficulties continued to beset studies on prevalence, with estimates ranging between 2 and 10% of the offender population having intellectual disabilities. Research on risk assessment has developed quickly in the last 7 years and current studies establish both the framework for assessment and new instruments that have been shown to predict offending incidents. There have been a number of promising studies on sex offender treatment and on the treatment of issues related to general offending. These studies continue to evaluate treatment progress in terms of improvements in behaviour, cognitive distortions and reductions of offending. One notable study had targeted reductions in sexual deviancy. With two exceptions, the main drawback in treatment studies continues to be the lack of control conditions. SUMMARY: These research studies will aid clinicians in the implementation of the assessment reviews and treatment programs for offenders with intellectual disabilities.

Pathways through services for offenders with intellectual disability: a one- and two-year follow-up study.

The pathways through services for offenders with intellectual disability were reviewed. Participants were 197 offenders with intellectual disability accepted into three types of community and three types of secure forensic intellectual disability services. They were first compared with 280 participants referred but not accepted into services and were then followed-up for 2 years to review pathways through services. Those accepted into services had a higher charge rate than did those who were referred (46% and 25%, respectively). The greatest diversity in pathway was seen in participants in community forensic intellectual disability and inpatient services. Individuals in secure settings showed the least diversity over time, and, similarly, a relatively high percentage of those accepted into generic community services remained in these services.

Referrals into services for offenders with intellectual disabilities: variables predicting community or secure provision.

BACKGROUND: There is a need for research to promote an understanding among service developers on why people with intellectual disabilities (ID) are referred to offender services in order for them to receive appropriate assessment and treatment. Previous studies investigating referrals into forensic ID services have concentrated on referral sources and administrative variables such as legal status. AIMS: To construct a predictive model for choice of service referral based on a comprehensive range of information about the clientele. METHOD: We conducted a case record study of 336 people referred to community services and 141 to secure provision. We gathered information on referral source, demographics, diagnosis, index behaviour, prior problem behaviours and history of abuse. RESULTS: Comparisons revealed 19 candidate variables which were then entered into multivariate logistic regression. The resulting model retained six variables: community living at time of referral, physical aggression, being charged, referral from tertiary health care, diverse problem behaviour and IQ < 50, which correctly predicted the referral pathway for 85.7% of cases. CONCLUSIONS: An index act of physical aggression and a history of diversity of problem behaviours as predictors against the likelihood of community service referral suggest that professionals have similar concerns about people with ID as they do about their more average offending peers; however, the more severe levels of ID mitigated in favour of community referral, regardless. Offenders with ID tend to be referred within levels of service rather than between them, for example, form tertiary services into generic community services.

Structural, item, and test generalizability of the psychopathy checklist--revised to offenders with intellectual disabilities.

The Psychopathy Checklist-Revised (PCL-R) is the most widely used measure of psychopathy in forensic clinical practice, but the generalizability of the measure to offenders with intellectual disabilities (ID) has not been clearly established. This study examined the structural equivalence and scalar equivalence of the PCL-R in a sample of 185 male offenders with ID in forensic mental health settings, as compared with a sample of 1,212 male prisoners without ID. Three models of the PCL-R's factor structure were evaluated with confirmatory factor analysis. The 3-factor hierarchical model of psychopathy was found to be a good fit to the ID PCL-R data, whereas neither the 4-factor model nor the traditional 2-factor model fitted. There were no cross-group differences in the factor structure, providing evidence of structural equivalence. However, item response theory analyses indicated metric differences in the ratings of psychopathy symptoms between the ID group and the comparison prisoner group. This finding has potential implications for the interpretation of PCL-R scores obtained with people with ID in forensic psychiatric settings.

The Ward and Hudson pathways model of the sexual offense process applied to offenders with intellectual disability.

The offense pathways model of Ward and Hudson has had a significant impact on work with sex offenders. Researchers have hypothesised that offenders with intellectual disability (ID) will show a predominantly avoidant and passive pathway. The present study classifies 62 sex offenders with ID according to the four self-regulation pathways. Allocation to pathways is highly reliable and, against prediction, most participants are allocated to approach pathways. Explicit/active offenders have a higher rate of contact offenses and a lower rate of reoffending. Automatic/passive offenders have a lower average IQ. There are no significant differences between groups on victim choice, previous offenses, or assessment of cognitive distortions. The results suggest that treatment may improve understanding of society's laws, promote self-regulation, and reduce recidivism for explicit/active offenders.

Risk assessment in offenders with intellectual disability: a comparison across three levels of security.

In mainstream offender samples, several risk assessments have been evaluated for predictive validity. This study extends this work to male offenders with intellectual disabilities. Participants from high-, medium-, and low-security settings, as well as community settings, were compared on a range of risk assessments. The Violence Risk Appraisal Guide, HCR-20-Historical Scale, the Risk Matrix 2000-C (combined risk), and the Emotional Problems Scales-Internalising discriminated between groups, with participants from high security having higher scores than those in medium security, who had higher scores than those in the community. The Violence Risk Appraisal Guide, all HCR-20 scales, the Short Dynamic Risk Scale, and the Emotional Problems Scales (Internalising and Externalising) showed significant areas under the curve for the prediction of violence. The Static-99 showed a significant area under the curve for the prediction of sexual incidents. The discussion reviews the value of these various scales to intellectual disability services.

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.

Predictive validity of the PCL-R for offenders with intellectual disability in a high security hospital: treatment progress.

BACKGROUND: Among mainstream offenders, the severe personality disorder of psychopathy has considerable importance as a construct. The disorder has long been associated with failure to make treatment progress. Previous work has identified that psychopathy as a disorder occurs in samples of offenders with intellectual disability (ID), and suggests that the Psychopathy Checklist - Revised (PCL-R: Hare, 1991, 2003) as a measure of the disorder has adequate reliability and validity (Morrissey et al., 2005). The present study aimed to compare the predictive power of the PCL-R in relation to treatment progress with a more general assessment of violence risk, the HCR-20 (Webster, Douglas, Eaves, & Hart, 1997). METHOD: A sample of 73 residents in a high security intellectual disability service, who had previously been assessed using the PCL-R and the HCR-20, were followed up at 2 years post-assessment, and their outcome determined in terms of two distinct dichotomous variables reflecting definite positive treatment progress and definite negative treatment progress respectively. RESULTS: In line with predictions, the PCL-R Total score and Factor 1 score (Interpersonal and Affective aspects of psychopathy) and the HCR-20 Total score were significantly inversely associated with a positive move from high to medium security hospital conditions within 2 years of assessment. However against prediction, the PCL-R Total score had incremental validity over the HCR-20. The PCL-R Total and Factor 1, but not the HCR-20 Total score, were also significantly associated with negative treatment progress in terms of a move to more restricted treatment conditions. CONCLUSION: Psychopathy, and in particular its interpersonal and affective manifestations, is a construct which appears to be associated with indirect measures of treatment progress in this high security ID group. However, caution should be applied in the use of a construct with potentially negative connotations in an already devalued population.