Assessment of neurodevelopmental disorders (ND) and comorbid substance use disorders (SUD) in a highly violent forensic population

Few studies have examined how neurodevelopmental disorders (ND) and substance‑use disorders (SUD) are evaluated in individuals convicted of severe violent offences. This study investigates whether forensic experts assess ND and SUD, and whether these conditions co‑occur in this population. One hundred Norwegian forensic psychiatric reports concerning severe violent crime were reviewed. The presence of standardised assessment tools and clinical descriptions of intellectual disability (ID), attention‑deficit/hyperactivity disorder (ADHD) and SUD was recorded. Associations between ADHD, SUD, and recidivism were analysed using chi‑square tests (α=0.05). Standardised assessment tools were employed in only a minority of reports. ADHD symptoms were documented in 50%of the reports, SUD symptoms in 76%, and other neurodevelopmental impairments in one‑third. Offenders with ADHD symptoms were significantly more likely to have SUD. Recidivism rates were higher among offenders who presented both SUD and ADHD compared with those with either condition alone. Neurodevelopmental symptoms, particularly ADHD, are frequently noted in forensic psychiatric reports, yet formal assessment tools are rarely used and seldom integrated into diagnostic conclusions. The co‑occurrence of ADHD and SUD appears to increase the risk of re‑offending, underscoring the need for systematic assessment and targeted interventions in this high‑risk group.