A third of young people aged between 14 and 18 have been the victims of online abuse in the past six months, research shows.
More than a quarter (27%) of those questioned by a youth charity said they were the subject of regular attacks, with most messages aimed at physical appearance (40%).
Others are targeted for their religion or race (16%) leaving almost a third (29%) of those questioned losing confidence in themselves.
But despite the detrimental effect, nearly a quarter (23%) admit they find trolling funny and one in 10 admit to carrying out trolling attacks.
The research was carried out by youth volunteering charity vInspired, which is launching a new campaign - Lolz not Trolls - to tackle the problem.
Backed by stars including Lauren Goodger, presenter Caroline Flack and singer Delilah, the campaign gives young people the chance to make a pledge not to troll.
It will give teenagers information on appropriate online behaviour by following a set of "netiquette" guidelines, with the aim of making social media channels a safer place.
Of the 2,000 youngsters polled about the issue, more than two thirds (67%) said they receive the abusive messages from someone they know.
Almost half (47%) say they keep the attacks secret.
The research showed evidence of a "digital disconnection" about trolling, with nearly one in five (18%) thinking messages sent in cyberspace are less damaging than insults hurled face to face.
Nearly half (49%) believe it is okay to say things online that you would not in person.
Professor Mark Griffiths, a social media expert who is working with vInspired on the campaign, said the phenomenon is growing as more youngsters grow up in the digital world.
He said: "The ability to remain anonymous online can lead to people saying what they may not in person over social networking channels."
He has helped create a downloadable guide of dos and don'ts for using social media, which is available from the campaign's Facebook page, www.facebook.com/DoSomethingUK.
Terry Ryall, chief executive of vInspired, said: "We have all heard of cases where youngsters have harmed themselves due to troll attacks - so writing a trolling message isn't harmless fun, it's potentially deadly.
"Our aim isn't to attack the trolls, but instead to get young people to do something positive and pledge not to be a troll themselves, abiding by the 'netiquette' guide we have created."
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