The wounds of childhood bullying last for decades - in both the health of victims and their bullies, a new study shows.

Children who are bullied grow into adults more likely to suffer depression and feelings of isolation, Victoria University research has found.

Meanwhile, the grown-up bullies are twice as likely to smoke, and are significantly more likely to suffer a long-term illness than those who were not bullies, researcher Jaimee Stuart said.

The effects were compounded in children who both inflicted and endured bullying: they suffered isolation and depression, as well as more frequently coming down with long-term illnesses.

"We matched people who were bullies in childhood for a variety of different things - similar cognitive abilities, coming from similar backgrounds . . .

"There's some constellation of behaviours, of which bullying is one, which is leading to bad health later on."

Stuart's soon-to-be-published research used a study done in Scotland in the 1950s, where teachers classified primary school children as either bullies or non-bullies.

She then used information from a follow-up survey of those children 39 years later, who are now in their late 40s and early 50s.

More than 600 of them were compared, and further divided into those who remembered being bullied in primary school and those who did not.

A range of mental and physical health measures, including levels of personal support and frequent alcohol consumption, were then compared among the four groups: bullies, victims, not involved and "bully-victims" - who experienced both.

"I don't think I was expecting to find such strong relationships - it was 39 years later, so you expect that there would be things in between that would make a difference," Stuart said.

There was potential for researchers to target and prevent behaviours such as bullying before they developed in the schoolground and workplace and caused long-term problems, she said.

She was now looking into how today's more bullying-aware generation saw the issue.

"There are things that actually are even more difficult for kids these days, with technology, and even the acceptance of this type of behaviour . . . so it may be slightly different for kids today, but that doesn't mean it's easier."

Mt Cook School principal Sandra McCallum said modern children often failed to identify bullying via Facebook and text message as abuse.

"They're really insidious types of bullying. Often kids don't view it that way but the impact is the same."

The long-term health effects of bullying were no surprise to McCallum, who said family and socio-economic pressures played a huge part in creating bullies.

Teachers at Mt Cook School were very proactive about bullying, asking children to identify even very minor incidents like face-pulling, McCallum said.

But to really tackle the problem, parents, sports clubs and other social leaders would need to adopt a no-tolerance approach, she said.

"It's about acting as a whole community and giving a collective message."

Today is Pink Shirt Day, a global initiative encouraging people to stand up against bullying and foster positive relationships.

The theme for 2014 is Speak Up, Stand Together, Stop Bullying.

CONSEQUENCES

Results of childhood bullying:

Bullies: smoke more, have more long-term illnesses

Victims: suffer depression more frequently and commonly feel isolated

"Bully-victims" (bullied others and were bullied): have more long-term illnesses, bouts of depression and feelings of isolation than those not involved in bullying

Source: Victoria University