Study finds genetic link between ADHD and criminal behaviour
Globally, ADHD affects about 5-7 percent of children and teenagers and around 2.5 percent of adults. It is often associated with negative life outcomes, including increased risk of involvement in crime.
A new study has found that individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) face a higher risk of criminal conviction, a link that extends to their family members.
ADHD is a neurodevelopmental disorder marked by inattention, hyperactivity, and impulsivity, often beginning in childhood and persisting into adulthood. These symptoms can interfere with decision-making, impulse control, and social functioning.
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Published in Biological Psychology, the study analysed data from 1,507,211 individuals born in Sweden. Researchers used national registers to explore whether ADHD and criminal behaviour co-occur due to shared familial or genetic factors, or if ADHD independently contributes to criminal risk.
Findings showed that individuals diagnosed with ADHD were significantly more likely to be convicted of both violent and non-violent crimes compared to those without the disorder. While men had more convictions overall, the relative increase in risk was greater among women, suggesting that ADHD in females may represent a more severe form or be linked to stronger behavioural risk factors.
Importantly, ADHD itself does not directly cause crime. The increased risk stems from traits such as impulsivity, executive dysfunction, and co-occurring conditions like conduct disorder or substance abuse. Impulsivity can lead to rule-breaking, while difficulties with planning and attention make it harder to foresee consequences. A need for stimulation may also drive risky behaviour.
Environmental factors play a role, too. Children with ADHD who grow up in disadvantaged settings, face academic challenges, or experience social rejection are more likely to develop antisocial behaviours. Brain differences in areas controlling reward and impulse regulation may further contribute.
Long-term studies show that ADHD symptoms in childhood, especially when combined with conduct problems, can increase the likelihood of criminal behaviour in adolescence and adulthood.
However, most people with ADHD do not commit crimes. Early interventions that improve self-control, emotional regulation, and social skills can significantly reduce risk.
The study also found that having a relative with ADHD increases the likelihood of criminal conviction, with risk rising alongside genetic closeness. Siblings of individuals with ADHD were more likely to have convictions than cousins, pointing to shared genetic or familial factors. This co-aggregation suggests that ADHD and criminal behaviour share underlying vulnerabilities influenced by both genes and environment.
Researchers emphasised that this does not mean ADHD causes criminal behaviour directly. Instead, traits like impulsivity and emotion regulation difficulties may be common to both. The stronger relative risk for women may reflect under-recognition of ADHD in females, meaning diagnosed cases could be more severe. It may also indicate sex-specific pathways linking ADHD to criminality.
Even after accounting for family confounding, ADHD appears to confer independent risk for criminal convictions. The findings have important clinical implications: individuals with ADHD, especially those with a family history, constitute a higher-risk group. Early diagnosis, treatment, and family-based support could help mitigate this risk. The elevated risk in women highlights the need for better diagnostic recognition and tailored interventions.
It’s crucial to note that these results reflect probabilities, not certainties. Most individuals with ADHD, and their relatives, do not engage in criminal behaviour. The study simply shows that the statistical risk is higher compared to the general population.
Like all register-based studies, this research has limitations. ADHD diagnoses were drawn from clinical and administrative data, which may miss undiagnosed or milder cases. Criminal convictions only reflect detected and prosecuted offences. Additionally, the findings are based on Swedish data and may not fully apply to other countries.
Nonetheless, the study offers compelling evidence that ADHD and criminal convictions are linked both within individuals and across families, largely due to shared genetic and environmental factors. This underscores the importance of early identification and support to reduce long-term behavioural risks.
Globally, ADHD affects about 5–7 per cent of children and teenagers and around 2.5 per cent of adults. It is often associated with negative life outcomes, including increased risk of involvement in crime.
Studies show that people with ADHD are 2–3 times more likely to be arrested, convicted, or incarcerated. They tend to encounter the justice system at a younger age and are more likely to reoffend. About one in four prison inmates meets the criteria for ADHD, far higher than in the general population.
Recent research found that men with ADHD are more likely to have criminal convictions than women with ADHD. However, women with ADHD have a higher relative risk compared to women without the disorder. For both sexes, the risk is greater for violent crimes than non-violent ones. These findings suggest the need to study men and women separately and to examine different crime types when exploring the ADHD-crime link.
Both ADHD and criminality are strongly influenced by genetics. Research estimates that genes account for about 70-80 per cent of ADHD and roughly 50 per cent of criminal behaviour. This shared genetic influence may partly explain the connection. However, the link persists even after adjusting for family factors, indicating that genetics alone doesn’t tell the full story.
Additional studies support this association. A 2015 meta-analysis of nine longitudinal samples involving over 15,000 individuals diagnosed with ADHD in childhood found they were 3.3 times more likely to be convicted and 2.9 times more likely to be incarcerated than peers without ADHD.
A 2022 study of 356 prison inmates found that those with probable ADHD had more convictions and entered criminal activity at an earlier age than those without the disorder. This highlights the higher prevalence of ADHD among incarcerated individuals and its link to recidivism.
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