ADHD linked to higher risk of criminal convictions within families

People with ADHD are at a higher risk of offending than those without an ADHD diagnosis. The same pattern appears among their relatives, according to a new study from örebro University. "This suggests that both genetic and environmental factors within families may play a role," says researcher Sofi Oskarsson.

Using Swedish national registers, the researchers tracked more than 1.5 million people born between 1987 and 2002, linking medical ADHD diagnoses to official criminal records. They then compared the risk of convictions among individuals and between twins, full siblings, half-siblings, and cousins.

The findings indicate that individuals with ADHD are significantly more likely to be convicted of both violent crimes and other types of crimes. Relatives of those with ADHD also face a higher risk of conviction, even if they do not have ADHD.

The correlation is somewhat stronger among women than among men.

“Since ADHD is often detected later in women, the higher risk may mean that those who are diagnosed often have more severe symptoms,” says Sofi Oskarsson, a researcher in criminology at Örebro University.

One of the largest studies conducted to date

The study, published in the journal Biological Psychiatry, is the largest to date to examine how ADHD and criminality co-vary within families across multiple levels.

The results highlight the importance of early identification and intervention for ADHD, particularly in families with a history of the condition. The researchers note that this can minimise the risk of adverse outcomes, such as criminal behaviour.

“Increased knowledge about the role of the family enables healthcare professionals to be more attentive to ADHD symptoms in relatives. This can help prevent impulsive and risky behaviour – and break patterns across generations,” says Sofi Oskarsson.

Preventive measures should target both genders and consider gender-specific needs and the additional challenges faced by women with ADHD, such as stigma and late diagnosis.

“Our research indicates that ADHD is not only a personal challenge but also part of a family-based risk profile. These insights are vital for developing early interventions and support that can lower the risk of criminal behaviour.”

Relevant outside Sweden

The study was conducted in Sweden, a high-income country with universal healthcare and a relatively low proportion of prisoners. Cultural, legal, and organisational factors can influence both how ADHD is detected and the chances of being convicted of a crime. However, a systematic review of the global prevalence of ADHD indicates that levels are fairly comparable across regions.

“This suggests that our findings could also be applicable beyond the Western world. However, further research is necessary in underrepresented regions to determine if the same pattern holds elsewhere,” concludes Sofi Oskarsson.