Children's counselling service ChildLine has seen the number of contacts from suicidal young people surge by a third in a year, a report has revealed.
The 24-hour service, which allows children 18 or under get in touch by phone, online chat and e-mail, also reported a 87% rise in contacts about online bullying in 2012/13 compared to the previous year and a 41% increase in contacts about self-harm.
The report - called Can I Tell You Something? - also showed the service for the first time ever received more contacts via online channels (59%) than by telephone (41%).
ChildLine founder Esther Rantzen said: " This report is a real wake-up call. Far too many of the nation's children seem to be struggling and in despair.
"It's so important that we support children to talk about issues and look out for signs that they're not able to cope. N o matter how hard pressed we are, we must commit to giving children time and space to talk about their lives. If they are concealing unhappiness, encourage them to open up and if they can't talk to you, maybe they can talk to ChildLine."
While online bullying rose by 87% in the period, contacts about bullying increased by 8%.
ChildLine, which conducted nearly 300,000 counselling sessions in the last year, said the 24-hour nature of online bullying meant there was "no escape" for young people.
More than 1,400 young people told the service they were experiencing racist bullying in 2012/13, up 69% on the previous year.
A common theme was for young people to be called a "terrorist" or a "bomber" and to be told to "go back to where they came from", ChildLine said.
Self-harm was mentioned in almost 47,000 counselling sessions, up 41% year-on-year, while suicide was mentioned in 4,500 contacts from children aged between 12 and 15 alone.
Peter Wanless, chief executive of children's charity NSPCC, which provides the service, said: " The issues facing children today are very different from those that faced us as children.
"Stranger danger, for example, rarely comes up in contacts to ChildLine but depression, self-harm, online bullying and even suicide contacts are increasing exponentially. If we are to help young people we need to listen to what they are telling us about the issues they are facing.
"We will be regularly publishing all our data showing what is increasing and where new emerging issues are appearing. It is essential that children's voices, concerns and experiences are shared, understood and addressed."
Family relationships remain a primary reason that children and young people contact ChildLine, with family problems mentioned in more than 86,000 counselling sessions in 2012/13.
:: Childline is a free and confidential service available online at www.childline.org.uk or by calling 0800 1111.