Crime and victimization among people with intellectual disability with and without comorbid mental illness

Forensic psychiatric issues in intellectual disability

Forensic psychiatrists and neuropsychiatrists are likely to encounter individuals with intellectual disability as they are over-represented in the judicial system. These individuals may have the full range of mental illnesses and comorbid conditions, including physical infirmity, sensory deficits, language impairment, and maladaptive behaviors. They are frequently disadvantaged in the judicial system due to lack of comprehension, lack of accommodations, and stigmatization. Decision making capacity may need to be assessed for health care, sexual autonomy, marriage, financial management, making a will, and need for guardianship. The usual approach to conducting an evaluation needs adaptation to fit the unique characteristics and circumstances of the individual with intellectual disability. The forensic consultant can assist attorneys, defendants, and victims in recommending accommodations and the expert witness can provide education to juries.

Association of intellectual disability with violent and sexual crime and victimization: a population-based cohort study

BACKGROUND

Intellectual disability (ID) is associated with violent and sexual offending and victimization, but the importance of neuropsychiatric comorbidity and severity of disability remains unclear.

METHODS

In a register-based cohort study of people born in Sweden 1980-1991 (n = 1 232 564), we investigated associations of mild and moderate/severe ID with any, violent and sexual crimes, and with assault victimization, stratified by comorbid autism and attention deficit hyperactivity disorder (ADHD). We defined ID by attendance at a special school or registered diagnosis and obtained data on criminal convictions and injuries or deaths due to assaults from nationwide registers until end of 2013.

RESULTS

Compared to people without ID, autism or ADHD, men and women with mild or moderate/severe ID and comorbid ADHD had elevated risks of violent crimes [range of hazard ratios (HRs) 4.4-10.4] and assault victimization (HRs 2.0-7.7). Women with mild ID without comorbidities or with comorbid autism also had elevated risks of violent crimes and victimization (HRs 1.8-4.6) compared to women without ID, autism or ADHD. The relative risks of sexual offending and victimization were elevated in men and women with ID without comorbidities (HRs 2.6-12.7). The highest risks for sexual offending in men (HRs 9.4-11.0) and for sexual assault victimization in women (HRs 11.0-17.1) related to ID and comorbid ADHD.

CONCLUSIONS

The elevated risk of violent offending and assault victimization in people with ID is largely explained by comorbid ADHD, whereas ID is independently associated with sexual crimes and victimization, even though absolute risks are low.

Characteristics and Prevalence of Lifetime Sexual Victimization Among a Sample of Men and Women with Intellectual Disabilities

This study examines the prevalence and characteristics of sexual victimization experiences suffered by people with intellectual disabilities (ID). The sample consisted of 260 adults with an ID diagnosis (154 men and 106 women), ranging in age from 20 to 71 years (M = 41.69, SD = 12.05). The results showed that 35% of the sample had been sexually victimized at some point in their life. Being a woman, being declared legally incapable, and having comorbid mental health diagnoses were the most relevant characteristics of sexual victims with ID. Fondling was the most reported victimization, and rape showed the greatest gender differences, with a higher risk for women with ID of being raped compared to their male counterparts (odds ratio = 4.28, p < .05). The offender was generally a known male adult, and the percentage of incidents reported to the authorities was very low (7.4%). The psychological consequences of abuse were general distress, anxiety, and depressive symptomatology. Intervention and prevention programs targeting this population, as well as the training of professionals and caregivers, are essential to deal with sexual victimization and to protect and ensure the quality of life of people with ID.

Exploring the victim offender overlap among people with an intellectual disability

BACKGROUND

While there is growing international evidence pointing to the increased risks of crime perpetration and victimisation for some people with an intellectual disability, the overlap between offending and victimisation (the victim-offender overlap) remains unclear.

METHOD

This study utilised a data linkage methodology of 2600 people with an intellectual disability, exploring their contacts with public mental health services and the police in Victoria, Australia.

RESULTS

Victim-offenders accounted for a small proportion of the sample (n = 148, 5.7%). The victim-offender overlap was evident for both violent and nonviolent nonsexual crimes, particularly for theft, burglary, and threat-related crimes. Key differences were also noted between males and females.

CONCLUSIONS

People with an intellectual disability who are both victim and offenders comprise a small but particularly complex justice-involved population. Future research should explore the victim offender overlap for males and females separately, as well as any additional risks and vulnerabilities associated with specific mental health diagnoses.

Risk Factors for Sexual Offenses Committed by Men With or Without a Low IQ: An Exploratory Study

Although risk factors associated with offending and recidivism are relatively well-established for mainstream sexual offenses, much less is known about men with a low IQ who have sexually offended (MIQSO), let alone those with forensic involvement. In this exploratory study, 137 convicted for the commission of at least one sexual offense and found not criminally responsible because a mental disorder were recruited in a maximum-security hospital. They were all assessed with the SORAG (static risk factors) and the RSVP (dynamic risk factors). Compared with MIQSO (N = 76), men with an average or higher IQ who have sexually offended (MSO, N = 61) obtained significantly higher scores on static factors related with general delinquency (histories of alcohol abuse, non-violent criminality, violent criminality, and sexual offense) and dynamic factors related with sexual delinquency, paraphilia, and recidivism (chronicity, psychological coercion, escalation, sexual deviance, and substance abuse). In contrast, MIQSO obtained significantly higher scores on major mental illness, problems with planning and problems with self-awareness. Logistic regressions revealed that both the SORAG and RSVP were useful to predict group membership. It is concluded that risk factors related with general and sexual delinquency better describe offenses committed by MSO, whereas risk factors related with mental disorder, lack of insight and contextual impulsivity better describe offenses committed by MIQSO.