Bullying can have a ‘severe impact' on a child's long-term health, a new study has shown.

US researchers monitored the progress of almost 4,300 children aged between 10 and 15. The children were interviewed periodically about any experiences of bullying and their overall mental and physical health.

Perhaps not surprisingly, the researchers found that if a child was bullied, they were more likely to have poorer mental health and lower self-worth.

However, they also found that if a child was chronically bullied, they reported increased problems with physical activities, such as walking, running and sports participation.

Those who were bullied in the past and were also being bullied in the present had the worst health scores.

And the longer a child was bullied, the more severe and lasting the impact was on their overall health.

"Our research shows that long-term bullying has a severe impact on a child's overall health, and that its negative effects can accumulate and get worse with time. It reinforces the notion that more bullying intervention is needed, because the sooner we stop a child from being bullied, the less likely bullying is to have a lasting, damaging effect on his or her health down the road," commented the study's first author, Dr Laura Bogart, of Boston Children's Hospital.

The researchers said that their findings show the importance of early intervention to stop bullying, but also the importance of intervening again, even if the bullying has stopped, to address any possible health effects.

"There's no such thing as a one-size-fits-all approach when it comes to addressing bullying. But providing teachers, parents and clinicians with best practices that are evidence-based could better assist those at the frontlines helping children cope with this serious problem and lessen the damage it causes," they added.

Details of these findings are published in the journal, Pediatrics.