IRISH children suffer the effects of cyber-bullying for longer than those in other EU countries.
As many as 14pc of Irish nine to 16 year olds are still upset two months or more after an incident, compared with 2pc across Europe, according to latest findings from the 25-country EU Kids Online survey.
"This is very high and it is an issue we have to deal with," said Simon Grehan of Webwise, a Department of Education-funded internet safety awareness initiative.
He was speaking at the launch of the Watch Your Space campaign, which includes a website devoted to young people to show their support for victims of cyber-bullying.
Mr Grehan said that along with schools, parents and industry, young people themselves had an important role to play in combating online bullying.
"When a bystander intervenes in a safe and effective way to support victims, or lets a bully know that their behaviour is unacceptable, this can inspire positive action by other bystanders," he said.
Watch Your Space is the first step in the Government's €500,000 action plan to combat bullying and was launched to coincide with Safer Internet Day today, which aims to change the attitude of bystanders.
People will be able to use the website to show their support for victims of bullying.
Gardai are also introducing a new module to their schools' education programme, called Connect with Respect, to help students understand the impact cyber-bullying can have.
Speaking at the launch yesterday, Garda Commissioner Martin Callinan said it was important to stand up to bullying, whether online or in the real world.
Meanwhile, Irish parents are being warned against supplying primary school children as young as six with smartphones because it increases their exposure to potential cyber-bullying.
Trinity College Dublin psychologist and cyber-bullying expert Dr Stephen Minton will tell a conference today that young children "are technologically smart but not mature enough to handle the issues that can arise, such as cyber-bullying".
The conference is being organised in conjunction with internet security firm TrendMicro.
New software and apps are being developed that can protect smartphones from cyber-bullying incidents by restricting them to the numbers of family and friends.
Donegal sisters Erin (13) and Shannon (15) Gallagher and Leitrim student Ciara Pugsley (15) took their own lives last year amid a worrying level of deaths linked to cyber-bullying.
In December, junior minister Shane McEntee took his own life after being the target of vicious social-media abuse.
The Bishop of Cork, Ross and Cloyne, Dr Paul Colton, threatened to end his use of Twitter after what he described as a "depressing" series of anti-Christian comments online.
Last month, a 15-year-old Cork girl was the target of social media abuse because she had refused to date a teenage boy.