The Familial Co-Aggregation of Attention-Deficit/Hyperactivity Disorder and Criminal Convictions: A Register-Based Cohort Study.

BACKGROUND

The association between attention-deficit/hyperactivity disorder (ADHD) and criminality is well established, but little is known about the familial liability of ADHD and crime across different types of relatives, from twins to cousins. In this study, we aimed to clarify the association between ADHD and crime by examining their co-aggregation both in the general population and across a range of familial relationships in a nationwide population-based sample, including separate analyses for men and women.

METHODS

We analyzed data from 1,507,211 individuals born in Sweden between 1987 and 2002. Using Cox proportional hazard regressions, we estimated the associations between clinically diagnosed ADHD and official crime records in individuals and families.

RESULTS

Analyses showed that individuals with ADHD had a significantly higher risk of being convicted of any crime-violent or nonviolent-compared with individuals without ADHD, with the risk being significantly higher for women than men. Additionally, individuals with a relative diagnosed with ADHD were at increased risk of criminal convictions, with some sex-based variations.

CONCLUSIONS

ADHD and criminal convictions co-aggregate within families, consistent with shared familial liability. Patterns across relatives and sexes suggest genetic contributions, with stronger associations in women. These findings may help inform risk assessment and prevention efforts.