Review of: Mohr-Jensen C et al, J Am Acad Child Adolesc Psychiatry 2019;58(4):443–452

ADHD has long been linked to antisocial behavior leading to arrests and incarcerations. Children and young adults with ADHD are more likely to be charged with anything from traffic violations to violent crimes. However, these associations do not prove causality. Is the ADHD causing these antisocial behaviors, or are there other psychosocial factors that would explain the findings? And if ADHD is indeed an independent risk factor for criminal behavior, can that risk be decreased through stimulant medication?

These big questions require population-based studies. Researchers evaluated data from Danish national medical and prescription registries and matched 4,231 children diagnosed with ADHD from 1995 to 2005, with controls based on sex and age. Follow-up data from an average of 22 years were obtained regarding arrests, incarcerations, substance abuse, time on stimulant medications, and other psychosocial factors. Nearly all (98%) of stimulant prescriptions were for methylphenidate, and most of the children (85%) were male.

After controlling for confounders such as psychiatric comorbidity, socioeconomic status, parental psychopathology, and other psychosocial factors, males with ADHD were 60% more likely (hazard ratio [HR] = 1.6) to be convicted of a crime and 70% more likely (HR = 1.7) to be incarcerated. For females, the effect was even more profound—they were 120% more likely (HR = 2.2) to be convicted and 190% more likely (HR = 2.9) to be incarcerated. However, when looking at times of active treatment with stimulant medication, the risk of conviction dropped significantly by 40% (HR = 0.6) for both males and females compared to time periods off medication. Incarceration risk also dropped by 40% (HR = 0.6) for males, but did not drop significantly for females.

CCPR’s Take
This study takes a mile-high view of a given population, looking for large trends over time. While population-based studies do not apply to every individual patient, knowing that appropriate treatment of ADHD may prevent criminal behavior is very encouraging. The data for more severe consequences of ADHD in females are particularly interesting, though they may stem from underrecognized mild ADHD in girls. For all cases, early recognition of the complex needs (related to poverty, trauma, etc.) of children with ADHD and supporting psychosocial treatment with medication can change lives.