One in every five children has suffered cyber-bullying
Youngsters said it damaged their confidence and self-esteem as well as mental and emotional well-being.
Many suggested cyber-bullying, like other forms of bullying, could "push people over the edge" leading to suicides. Respondents in the online study examining the scale of cyber-bullying and its effects wrote about cyber- bullying "messing with people's heads", and causing "upset" and "depression".
Researchers found that cyber-bullying - using the internet or mobile phones - was far more prevalent among girls.
Of those surveyed, 18.4 per cent admitted that they were a victim of cyber-bullying and 69 per cent of those bullied were female.
Steven Walker, who led the research which surveyed almost 500 young people aged between ten and 19, said that while most online interactions were neutral or positive, the internet provided a new method of bullying.
"Some people who cyber-bully think that they won't get caught if they do it on a mobile phone or on the internet," he said.
"The people who cyber-bully are usually jealous, angry or want to have revenge on someone, often for no reason at all."
More than a quarter of victims said they had stayed away from school because of it, and more than a third had stopped socialising outside school.
Mr Walker, principal lecturer in child and adolescent mental health at Anglia Ruskin University, said: "Cyber-bullies often think that getting their group of friends to laugh at someone makes them look cool or more popular.
"Some people also bully others as a form of entertainment or because they are bored and have too much time on their hands. Many do it for laughs or just to get a reaction.
"Many of the respondents in our study thought that cyber-bullies do not actually think they are bullying. In the main, they thought cyber-bullying was seen by bullies as merely a form of 'harmless fun', a joke and therefore not an issue. "
Brian Donnelly, director of Respectme, an anti-bullying organisation, said: "We are glad to see a study focusing not on the characteristics of people doing the bullying or receiving it, but on the effects on mental health and well-being of those being targeted.
"We tell parents to connect with their children and to think of the internet as a 'place' not a 'thing'. A young child would not be allowed out into the city centre on their own to wander around by themselves - the internet is no different.
"However, relationships have their ups and downs and we don't want children finding themselves with criminal records. We need to teach them that what may have seemed like a throwaway comment can be round the school in two hours, causing upset and damage."Parents can put controls on their children's computers, but we need to try to resolve things by including children in discussion, setting boundaries, and agree consequences if these are broken."