KEY POINTS:
Unchecked antisocial behaviour in childhood leads to poor health in later life, new findings from an internationally-acclaimed long-term New Zealand study show.
The latest results from the Otago University study, which has followed 1000 people since they were born in Dunedin in 1972 and 1973, has found links between antisocial behaviour and poor physical health in adulthood.
The findings, a collaboration between the Dunedin research unit and colleagues at the University of London, appear this week in the American journal Archives of General Psychiatry.
Unit director and paper co-author Professor Richie Poulton said other studies had shown that childhood antisocial behaviour led to adult crime and mental disorder, but this was the first study to show a link to poor adult physical health.
That included injury, sexually transmitted diseases, dental disease, reduced immune function, and an increased risk of heart disease.
The study has tracked 526 males through childhood, adolescence, and adulthood.
The most recent assessments were done when they were 32.
Boys whose antisocial behaviour persisted into adulthood were more than three times as likely as others to have symptoms of chronic bronchitis and gum disease, 2.9 times more likely to show markers for later heart disease and stroke, and 2.2 times more likely to have the herpes virus.
Males who exhibited high levels of antisocial behaviour as children, but reduced this behaviour in adulthood did not have the same level of poor health, said Professor Poulton.
"You're talking about kids in the sandpit at preschool fighting and bullying each other, and by 13, these kids are converting cars and by 18, they're bashing people and raping people.
"That's the sort of development of this hard core antisocial behaviour.
"It's early onset and persistent - in order words, there's a whole bunch of kids who are naughty during childhood but they don't persist. They grow out of it.
"We're talking about the 10 per cent of males who are identifiable early, with a whole bunch of risks, and who continue to behave in an antisocial way over their life."
Professor Poulton said these findings were consistent with other indicators of poor health, such as being in a low socio-economic grouping.
The findings could help the justice and health systems, as reducing antisocial behaviour early could help combat future crime and violence, and reduce the overall health burden.
"You have this hard core of 10 per cent males, and then you've got the 25 per cent who exhibit antisocial behaviour during childhood but grow out of it.
"It's the real tough test - if you want to intervene early, which ones are the ones that are going to go on [to offend in adulthood]? We're really at the pointy end of that particular research endeavour."