Risk factors for recidivism in offenders with intellectual disabilities

Abstract

The literature on risk factors for recidivism in offenders with intellectual disability (ID) is inconsistent and inconclusive compared to the field of mainstream criminality where the predictive efficacy of social psychological and criminological factors is well established (Gendreau, Little & Goggin, Criminology, 34, 575–607, 1996). Criminological variables have also been reported to have superior predictive efficacy over clinical variables in a large meta-analysis of recidivism in other mentally disordered offenders (Bonta, Law, & Hanson, Psychological Bulletin, 123, 123–142, 1998). The current study replicated this finding in a sample of offenders with ID (n=145) discharged from four independent sector medium secure units in the UK between 1990 and 2001. Over a two-year follow-up period criminal history variables were significantly related to general recidivism. A subsequent analysis found the Offender Group Re-conviction Scale, a criminogenic risk assessment instrument designed for use in general offenders, to have excellent predictive efficacy in offenders with ID.

Keywords:

• intellectual disability
• recidivism
• criminal history risk factors
• OGRS

Notes

1. Diagnostic classification systems such as ICD-10 (World Health Organization, 1992) and DSM-IV-TR (American Psychiatric Association, 2004) outline the criteria required for a diagnosis of mental retardation to be: significantly sub-average intellectual functioning with an IQ of less than 70 (confidence interval of 67–75); a concurrent deficit of adaptive functioning; and age of onset before 18 years. Various terms are used throughout the research literature to describe these criteria: namely mental retardation, learning disabilities, developmental disabilities and intellectual disabilities (Holland, Clare, & Mukhopadhyay, 2002). These terms all refer to the same cluster of criteria required to satisfy a diagnosis of mental retardation (Holland et al., 2002). In the present paper it has been decided to use the term intellectual disabilities as it is the most widely used term in the research literature.

2. This particular point did not precisely replicate Bonta et al. (1998), with fewer days hospitalized predicting recidivism in the Phillips et al. (2005) study and more days hospitalized predicting recidivism in the Bonta et al. (1998) analysis. The reasons for this discrepancy may lie with the samples employed, but requires further study and is beyond the remit of the present study.

3. Quinsey et al. (2004) evaluated the ability of the VRAG to predict violence in a community sample of offenders with ID, although the violence recorded in the study was only against other clients and staff in their community accommodation and therefore it is felt to be akin to institutional violence.

4. Unless otherwise stated, we do not differentiate between the two versions of the test which will collectively be termed the OGRS.