A new study published in Biological Psychiatry has found that people with attention-deficit/hyperactivity disorder (ADHD) are more likely to be convicted of crimes compared to those without the condition. The research also indicates that relatives of individuals with ADHD face a higher risk of criminal convictions, suggesting that both genetic and environmental factors within families may contribute.
The researchers analyzed data from Swedish national registries, tracking over 1.5 million people born between 1987 and 2002. They linked medical diagnoses of ADHD to official crime records and compared risks across different family relationships, including twins, siblings, half-siblings, and cousins.
John Krystal, MD, Editor of Biological Psychiatry, stated: "We have long known that ADHD puts people at risk for risky, impulsive behaviors, including crime. We have also been aware that ADHD risk has a genetic component. This important paper now brings these threads together to show that families that carry ADHD risk also are at risk for having family members who engage in criminal activity. These data highlight the importance of early identification and treatment of ADHD in high-risk families to mitigate this risk."
Lead investigator Sofi Oskarsson, PhD, from örebro University in Sweden explained: "We found that individuals with ADHD were several times more likely to have criminal convictions for both violent and non-violent crimes. Importantly, relatives of individuals with ADHD also showed increased risk, even if they themselves did not have ADHD, pointing to shared familial liability. The associations were to some extent stronger among women than men, indicating possible sex-specific factors in how ADHD relates to criminal outcomes." She added: "Because ADHD may be underdiagnosed or mischaracterized in females, the higher relative risk among women may indicate that when ADHD does occur, it reflects a more severe or concentrated set of underlying risk factors."
The study was conducted in Sweden—a country with universal healthcare and low incarceration rates—but the authors note that global studies suggest similar rates of ADHD when using consistent diagnostic criteria. This suggests the findings could apply beyond Sweden's borders but further research is needed in other regions.
The results point toward the need for prevention strategies tailored for both males and females while considering additional challenges faced by women with ADHD such as stigma or delayed diagnosis. Early detection and treatment—especially within families where there is already a history—could help reduce negative outcomes like involvement with the criminal justice system.
Dr. Oskarsson concluded: "At a time when awareness of ADHD is increasing, understanding the broader familial patterns helps us recognize ADHD not only as an individual challenge but also as part of a family-level risk profile. These insights are critical for informing early intervention and support strategies that could reduce negative outcomes like criminality."
