Dutch forensic patients with and without intellectual disabilities: A comparison of demographic, offence, and diagnostic characteristics.
Dutch forensic patients with ID arrive younger, carry more violence history, and show higher addiction rates—plan treatment and safety around these facts.
01Research in Context
What this study did
Keulen-de Vos et al. (2022) compared two groups of Dutch forensic patients: those with intellectual disability and those without.
They looked at age at admission, past violent crimes, and rates of substance-use disorder.
The goal was to see if offenders with ID enter the system differently and carry extra risks.
What they found
Patients with ID were younger when admitted and had more prior violent convictions.
They also showed higher rates of substance-use disorder than non-ID offenders.
These patterns suggest a more complex risk profile that teams need to plan for.
How this fits with other research
Lancioni et al. (2008) found that one in ten Norwegian prisoners has ID, using the same quick screen (HASI) that To et al. (2015) later validated in Dutch.
Marije’s 2022 forensic-hospital data line up with those prison numbers, showing the justice pipeline is packed with people who have ID plus addiction.
To et al. (2015) proved that substance use does not throw off the HASI scores, so the high addiction rate Marije reported is real, not a testing error.
Together the three papers paint the same picture across settings: offenders with ID are common, often violent, and frequently using drugs or alcohol.
Why it matters
If you work with offenders who have ID, expect earlier, more violent entries and heavy addiction.
Build shorter, clearer programs and add substance-use modules from day one.
Use the Dutch HASI to flag ID quickly, then fold Marije’s risk factors into your behavior plan.
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02At a glance
03Original 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.
Research in developmental disabilities, 2022 · doi:10.1016/j.ridd.2022.104255