The number of people harming themselves deliberately has leapt by a third in the past five years, according to new figures seen by The Independent on Sunday. The biggest rise in self-harm and attempted suicide has been among young women between the ages of 16 and 24 as they struggle to cope with the pressures of modern living in Britain.

There were 97,871 hospital admissions for deliberate self-harm in England in 2007-08 – 4,337 of them for children under the age of 14. Meanwhile, one in eight young women admitted to self-harm in 2007 – an 80 per cent increase since 2000.

According to new research published by the World Health Organisation (WHO), the growing gap between rich and poor has led to an increase in mental health problems such as depression and self-harm in countries including the UK and US. People are surrounded by stories about the rich and famous – lifestyles that are unattainable for the majority. These inequalities cause psychological and physical stress which leads to mental and physical health problems, the report concludes.

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Another possible reason for the rise is a growing trend among young people to rely on extreme measures such as overdoses and wrist cutting to communicate their anger and distress, say mental health experts. Emergency doctors report an increase in alcohol-related self-harm as people turn to drink to cope with difficult feelings and experiences.

Experts called on the Government yesterday to treat mental illness as a wider public health and social problem rather than just spending money on specialist treatments and psychological therapies. The incidence of self-harm has risen despite record levels of government spending on mental health services since 2000.

Dr Andrew McCulloch, chief executive of the Mental Health Foundation, said: "Self-harm is often a secret activity and people will avoid going to hospital if possible. So the fact we've seen such a substantial rise in hospital admissions is worrying and could be the tip of the iceberg.

"Research we carried out last year with Girlguiding UK showed that even very young girls are feeling the strains of modern life and the pressure to grow up too quickly. A rise in reported self-harm among young women in their late teens and early twenties fits in with that picture, and unfortunately suggests that there's a whole generation of young women who feel such emotional distress, and that many of them are turning to self-harm in an attempt to cope."

The majority of people who were admitted to hospital for self-harm last year had taken an overdose of legal medications. More than 6,000 people needed hospital treatment after cutting themselves – a rise of 80 per cent in five years.

Buried in last month's annual Psychiatric Morbidity Survey were alarming figures about young women: nearly 12 per cent of women aged between 16 and 24 admitted to self-harm – a rise of 80 per cent since 2000. Self-harm is the second most searched-for subject on the mental health charity Mind's website, yet the majority of people who self-harm will never tell anyone or seek help.

Health professionals are bracing themselves for increases in depression and anxiety, as well as a rise in the number of people who self-harm or commit suicide as the recession sets in. Dr Peter Byrne, a consultant psychiatrist in A&E and self-harm specialist, said: "It is much harder to be an adolescent these days. Young people are surrounded by an obscenely rich celebrity culture, and kids want to have those things too. Others I come across are excluded from society and cannot imagine living beyond 30. And two-thirds of the young people I see in A&E have been drinking alcohol. Their drinking is angry, morose, avoidant, and when this happens someone is much more likely to self-harm. If you look at the unhappiest populations in the world, it is those with the greatest income inequality."

Published earlier this month, Mental Health, Resilience and Inequalities by the WHO and the Mental Health Foundation revealed a strong link between income inequalities and poor mental health. Inequality is now known to be a constant trigger for the "fight or flight" response in human beings. Over time, the perpetual stress is thought to get "under the skin" and lead to permanently raised levels of stress hormones such as cortisol, as well as causing depression, higher blood pressure and other biological changes associated with stress and mental illness.

Lynne Friedli, author of the report, said: "We have to face up to the fact that mental well-being depends on reducing the gap between rich and poor. A large divide leads to a mentally unhealthy society, and many associated social problems. In the UK in particular, we've failed to acknowledge this link, preferring instead to blame people's lifestyle choices."

Dr McCulloch said: "We know that the UK has become a much more unequal place in the past few decades and we also know that people's mental health seems to have worsened at the same time. Now we're beginning to understand how these two trends might be linked, and how living with inequality can have very real effects on the mind and body."

Since 2000, the Government has spent millions of pounds on improving mental health services in the community and A&E departments. As a result, far fewer people are admitted to hospital unnecessarily, according to the National Audit Office. More recent efforts have concentrated on specialist help for children and adolescents but some experts argue that these efforts miss the point.

The shadow health minister Anne Milton, who obtained the hospital admission figures, said: "These startling figures are yet another example of the surge in mental health issues that the UK has experienced in recent times. The sharp rise shows that government policy has failed to sufficiently prioritise mental health and early intervention. We must focus more on reducing stigma and proactive prevention rather than crisis management."

Dr McCulloch said: "Most children and young people won't go near a place labelled 'mental health' if they can help it, so we have to start supporting their wellbeing in places they will go – youth centres, sports clubs and so on – before they even get to the point of needing a specialist mental health service. We also know young people between 16 and 25 fall between two stools, and neither children nor adult mental health services suit their needs. This is key problem with the current system as that age group is particularly vulnerable. Just when they need continuity of support, they fail to get it."

Rufus May, a clinical psychologist in Bradford, said: "Demonised by the media, subject to scrutiny and evaluation in terms of their looks and appearance, and a school system that is increasingly prescriptive, young people don't have space to be creative or learn how to express how they feel. Self-harm is a release. It anaesthetises people from the pain of feeling wretched and unworthy. It helps us escape the pain of living in a competitive, self-conscious world where we rarely feel that we are making the grade. It can also be an expression of anger. This is one way to briefly be powerful and take back control. The scars of self-harm are like protest graffiti, and we need to listen to it. The answer is not more therapy. We need to teach young people how to communicate and care for themselves and one another."

Selina's story: 'I wanted to punish myself for being such a failure'

Selina Aktai, 39, from north London, cut herself almost constantly between the ages of 12 and 36

"There was a build-up of unhappiness from when I was really young. After my mum died when I was 12, my dad remarried really quickly and the whole family changed. I felt out of control, angry at my dad and completely alone. One day I was shaving my legs in the bathroom and I cut myself accidentally. Watching the blood trickle into the water made me feel so much better; it felt like a release. From then I started cutting my legs in secret, every other day, as a way to convey how I felt. I would cut until I could see blood and then cover them with plasters.

"I never told anybody. We didn't do that in our family. We were taught to have good manners, to respect our parents and do well at school; not to talk about our thoughts and feelings. I was acting out at school, but everyone just thought I was difficult. No one asked me how I felt.

"After a few years I started to have suicidal thoughts and began to experiment with paracetamol; I wanted to see how far I could go. I was holding down a job, but then my dad convinced me to get married in Bangladesh. It didn't work out, and I came home. I then spent five chaotic years travelling around the country, completely out of control, cutting myself and taking overdoses, but still I didn't tell anyone. Deep down, I knew I was taking risks with my life, but I didn't know any other way. By this stage cutting no longer made me feel better: I did it because I wanted to punish myself for being such a failure.

"Even when I got my life together, settled down and got a job with the council, I still hurt myself at times, and the suicidal thoughts got stronger whenever I tried to resolve the difficulties with my family. It all came to a head eventually, and I made a plan to jump off Westminster Bridge. That's when I ended up in hospital in 2005.

"Hospital is not the right place for people who self-harm. I got myself out and after six months got an appointment with a fantastic therapist – the first time I found someone who listened to me, understood my culture and helped me to express how I felt with words. I haven't hurt myself for many, many months and feel much more in control of my life. My family still has no idea about what I was doing and how bad things got."