THURSDAY, Feb. 23, 2017 (HealthDay News) -- A new study suggests that teenage boys who are chronically sleepy in the daytime may be at higher risk of becoming violent criminals as adults.
A team of U.S. and British researchers identified a link between frequent daytime drowsiness in the high school years to a 4.5-times greater likelihood that a boy would grow up to commit a violent offense by his late 20s.
"It's the first study to our knowledge to show that daytime sleepiness during teenage years are associated with criminal offending 14 years later," study author Adrian Raine said in a news release from the University of Pennsylvania. He's a professor of criminology and psychology at the university.
But at least one psychiatrist who reviewed the findings believes it may be premature to say sleepy teens are destined for a life of crime.
Frankly, said Dr. Victor Fornari, "it is hard to find an adolescent who has had enough sleep and is not tired."
The study couldn't prove a cause-and-effect link, he noted, and its takeaway message remains "unclear."
"So many other factors other than sleep play into the outcome of criminal behavior," said Fornari, who directs child and adolescent psychiatry at Cohen Children's Medical Center in New Hyde Park, N.Y.
In the study, Raine and his colleagues conducted specially designed "sleepiness tests" with more than 100 boys, all of whom were 15 and attending one of three high schools in northern England.
In a lab setting, each teen was asked to rank his degree of sleepiness between the hours of 1 p.m. and 3 p.m. Researchers also conducted brain activity measurements during that time frame, alongside attention behavior testing.
The boys' socioeconomic background information was noted, and the students and their teachers were also asked to report on any antisocial behavior the teens had engaged in.
Then, many years later, the same team looked at criminal records to see which of the teens had displayed criminality by the time they reached the age of 29.
The result: Seventeen percent of the teens had been convicted of committing a violent crime and/or property offense by their late 20s. After accounting for certain variables, the study found that teenage daytime drowsiness did seem tied to a higher odds of adult violent crime.
But family background seemed to matter, too: Boys who came from relatively poorer families were more likely to have daytime drowsiness as teens and, in turn, be more prone to violent crime as adults.
What's the possible connection? According to Raine, "daytime drowsiness is associated with poor attention. Take poor attention as a proxy for poor brain function. If you've got poor brain functioning, you're more likely to be criminal."
Still, Fornari remains unconvinced. "I am not sure what this study is really contributing to the body of knowledge," he said.
And Raine also stressed that, of course, not all sleepy male teens will turn out to become criminals.
Still, encouraging better sleep in the teenage years couldn't hurt, he said.
"More sleep won't solve crime, but it might make a bit of a dent," Raine said.
The findings were published Feb. 23 in the Journal of Child Psychology and Psychiatry.
There's more on teens and sleep at the National Sleep Foundation.