Dutch forensic patients with and without intellectual disabilities: A comparison of demographic, offence, and diagnostic characteristics

Abstract

Background: Patients with an intellectual disability (ID) and offending histories constitute a challenging clinical group. The present study examined commonalities and differences in demographic, diagnostic and offence characteristics in patients with and without intellectual disabilities who were either convicted for violent or sexual offences and who resided in mandated care in the Netherlands.

Method: We compared 165 offenders with an ID to 249 offenders without an ID. We compared both groups by type of offence (i.e., sexual versus violent offence) using Mann-Whitney U-test or independent samples t-tests for continuous variables and Chi-square tests for categorical variables.

Results: In general, forensic patients with an ID were younger at admission (U=357, z = -12.668, p < .001), had more prior convictions for violent offences (χ²(1)= 6.175, p = .013) and more prevalent diagnoses of substance abuse disorders (χ²(1)= 9.266, p = .002) than those without an ID. Similar results were found for patients with IDs with sexual offence histories.

Conclusion: A clear understanding of distinct characteristics of forensic patients with intellectual disabilities is crucial in understanding (sexual) violent behavior in this population as it mayassistclinicians in prioritizing interventionstrategies.

Keywords: Characteristics; Intellectual disability; Offence; Sexual offending; Violence.