The research found that 85) or teachers (1 of teens said they had never reported the problem to the relevant social media website, despite many sites offering one click abuse reporting.
Teens don't believe reporting abuse makes any difference; over a third of those deciding not to report the incident said it was because they felt like no action would be taken. The study suggests trolling is now more prevalent than real-life bullying: 49 that had online.
Phil Kingsland, Site Director at knowthenet.org.uk, said: "Understanding the potential impact trolls can have on teenagers is the first step to engaging with your youngsters about this, and helping them to deal with these issues.
"Online trolling can be as traumatic as physical bullying in the playground, so it's important that action is taken quickly and parents and teachers work together to monitor and deal with the issue."
Emma-Jane Cross, CEO and founder of the charity BeatBullying added: "Bullying both on and offline continues to be a serious problem for a huge number of teenagers and we cannot ignore its often devastating and tragic effects.
"We work with hundreds of young people being cyber-bullied or trolled so badly that it can lead to depression, truancy, self-harm, or even force them to contemplate or attempt suicide.
"What's also concerning is that many young people could be suffering in silence. The most important thing for young people to remember is not to ignore it. If you see cyber-bullying going on, report it to the site concerned and offer your support.
"If you're being cyber-bullied, always save any bullying messages, posts, pictures or videos you receive or see.
"Never respond or retaliate, as this can just make things worse, and block any users that send you nasty messages."
Knowthenet has launched a trolling hub with lots of advice on how to deal with online bullying and trolling. This provides details of how to report online bullying and trolling.
The top three tips to tackle online trolling:
1. Don't feed the trolls – trolls feed off your response so whatever you do, never reply.
2. Tell a mate, a teacher, a parent or someone you trust about it as soon as possible.
3. Collect evidence of email or message trails in case it gets more serious. You can find a checklist of what to keep at www.knowthenet.org.uk/trolling
1. Listen to your teenager and discuss the problem they're having.
2. Help your child with the practical elements of gathering evidence but be respectful of their privacy so ask before reading their messages.
3. Support your child in reporting the abuse to the social network, online messaging service, or even the authorities and keep monitoring the situation on a regular basis.