A survey of over 800 young people found that 22 per cent of males and females aged 11 to 19 had self-harmed, while 56 per cent said they know someone who has.

Of those that self-harmed, over 70 per cent admitted to cutting, 49 per cent used punching, 14 per cent resorted to burning and 10 per cent tried poisoning.

The study, commissioned by mental healthcare specialists Affinity Healthcare, found nearly half the self-harmers blamed depression for their actions. Anger triggered 17 per cent, while stress and relationship problems were both named by 10 per cent of respondents.

Dr David Kingsley, Affinity Healthcare's lead consultant adolescent psychiatrist, warned self-harm was becoming an increasing problem.

"As a society we need to sit up and take notice when one in five young people and a third of girls are admitting to feeling so bad about themselves that they need to self-harm," he said.

"The massive increase in family breakdown and the extra pressure that is put on our young people in schools may be part of the explanation but more research is urgently needed to understand this better."