Research Identifies Link Between Childhood ADHD and Adult Crime

Published: October 19, 2009

New Haven, Conn. — Schoolchildren with attention deficit/hyperactivity disorder are substantially more likely to engage in many types of criminal activity such as burglary, theft and drug dealing as they grow older, a new study by the Yale School of Public Health has found. The research was published in The Journal of Mental Health Policy and Economics.

An analysis of more than 10,000 adolescents who were later surveyed as young adults found that children with ADHD were twice as likely to commit theft later in life and had a 50 percent higher incidence of selling drugs. The research results are believed to be the first evidence of a link between illegal activity and the childhood condition commonly known as ADHD that uses a national sample of individuals.

Authors Jason M. Fletcher, assistant professor at the school, and Barbara Wolfe of the University of Wisconsin-Madison say the findings suggest that children exhibiting ADHD symptoms should be viewed as an at-risk group and that intervention programs might be appropriate.

Researchers estimate that crimes where ADHD is a factor cost society $2 billion to $4 billion annually. “While much research has shown links between ADHD and short-term educational outcomes, this research suggests significant longer-term consequences in other domains, such as criminal activities,” said Fletcher, the study’s lead author. He added, “We also found important differences in the association between adult crime and the type of childhood ADHD symptoms—whether hyperactive or inattentive or both.”

It is estimated that ADHD affects between 2 percent to 10 percent of schoolchildren in the United States. The condition is far more prevalent in males than females and is much higher among close relatives than in the general population, suggesting a genetic origin. Treatment for ADHD, meanwhile, has increased sharply over the past 20 years with pharmaceuticals, such as Ritalin, now commonly used.

Fletcher said the link between ADHD and criminal activity will be further investigated by examining whether pharmacological treatments may reduce the risk of illegal activities as an adult. He is also investigating the relationships between childhood ADHD symptoms and labor market outcomes, such as employment and earnings.

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