Radley College, the elegant boys’ boarding school south of Oxford, has always prided itself on its reputation for cultivating good manners and generosity in its pupils. In many respects Charlie Waller epitomised the Radley spirit. A great bear of a boy, he was loyal, kind, funny and popular, with a strong sense of justice and fair play as well as being a towering physical presence as head of house and captain of the rugby first XV.

Teachers can picture him still: giant-framed and full of life but gentle, solicitous, a model pupil. Charlie built on his Radley success through university at Durham and on into the advertising industry, where he became a successful account manager, inspiring clients with his wit, warmth and dependability.

But in September 1997, at the age of 28, Charlie drove to a wood in Berkshire and killed himself by channelling exhaust fumes into his car. In a suicide note he wrote: “I don’t think I am very well at the moment.” In truth Charlie Waller had been suffering from depression, a fact he managed to keep well hidden from all who knew him. It was the weekend of Princess Diana’s funeral and, although he was possibly influenced by the emotionally charged atmosphere of the time, his suicide came as a shock to his friends and family.

Only with hindsight have those close to him identified the signs of depressive illness - bouts of lethargy, concentration difficulties, agreeing to meet friends and then not turning up - but they lacked the knowledge to interpret them, and Charlie failed to seek their help or that of a doctor until it was too late.

Five hundred people attended his funeral, many of them friends from school, college or work, unable to comprehend why this loving and much-loved friend had taken his own life. But once through their initial raw grief, Charlie’s family - brothers Richard and Philip and parents Rachel and Mark - determined that other families should not have to go through what they were going through. They set up the Charlie Waller Memorial Trust with two clear aims: to improve the treatment of depression in primary care (in family doctors’ surgeries) and to educate young people in school, principally sixth-formers, about depression and its warning signs.

The work of the trust is already having an effect. It has raised almost pound;500,000, and Charlie’s friends in advertising have produced a booklet, Depression and How to Deal with It. Last year the trust ran a pilot competition in seven schools, including Radley, Bradfield College in Berkshire, Holland Park comprehensive in west London, and Winchester College in Hampshire, offering hundreds of pounds in prizes to pupils who designed the best websites on depression. This year it plans to extend that pilot to 60 schools before turning it into a national project.

Following a visit from the trust, pupils at Radley produced seven sites for people of their own age. Unlike Charlie and his peers, many of them feel they are informed and therefore forearmed to deal with depression, which commonly hits young people in their late teens and early twenties, and to recognise signs of it in their friends.

Charlie’s legendary success and popularity in school fuelled their enthusiasm. Henry Morris, 17, says: “I thought it would be good to learn about making websites, but the more I got into it the more I realised the importance of learning about depression. I have never come across it in school or in my family, but the fact that no one knew Charlie was depressed brings it home to you.

“You often hear about celebrities suffering from depression, but associate that with drugs and lifestyle. I thought depression was for people whose lives were not going well and who couldn’t face their problems.

“I thought of it as the consequence of bad luck, not a medical condition. But to know that it hit somebody like Charlie Waller, a stable, real, loveable, but average sort of guy, makes you realise it can affect anybody.”

Jayme Goldstein, 14, aimed to create a site for younger teenagers, bright and breezy, full of flashing symbols and easy-to-read text. “When you hear about somebody like Charlie you tend to think something serious must have happened in his life to make him depressed,” he says. “But when you learn that the smallest thing can trigger it, you’re more likely to look out for it in your friends.”

Daniel Kenyon Jones, 17, who created the winning website, says: “There was a boy here who was suffering from clinical depression and none of us had a clue about what was happening to him. But now I have some understanding at least and that’s good. I had no idea it was such a common illness.”

Simon Thorn, head of personal and social education at Radley, believes the competition was an attractive and effective way of teaching young people about the illness. “They’re not likely to turn up to or be interested in a lecture on depression, but they will work on computers designing something that appeals to others of their own age group.”

Hamish Aird, Radley’s deputy head, was also Charlie Waller’s tutor and became a firm friend of the family. “Charlie was the sort of person people relied on,” he says. “He was a big, warm-hearted, friendly extrovert. He came from a very close-knit, loving, successful family and whenever you went to the home there were always lots of young people about. He was very positive at school and certainly showed no signs of depression then. His death made lots of people feel very strongly that they had to do something.”

copywriter Ben Walker was a close colleague of Charlie Waller’s at the advertising agency, Simons Palmer Clemmow and Johnson, where they were both working when he died. He has designed the trust’s website and booklet and has thrown himself into raising funds from his own industry. Charlie was the sort of person, he says, who could party all night and still be first into the office in the morning, and latterly took on more and more work - which Walker now believes was a way of trying to escape what was happening “inside his head”.

“I had no idea he was depressed and went through a horrible, horrible time after his death,” he says. “Latterly, he had seemed a bit down and didn’t turn up sometimes when he’d been invited out by mates. But I had this strange idea that a couple of drinks would get him out of the blues.”

Mark Durden Smith, who went to school and university and shared a house with Charlie, explains how friends all failed to spot the danger signs. “Charlie was a high achiever,” he says. “He was extremely funny and would do anything to make people happy. But he did go through bouts of great lethargy. It seems terrible now, but we used to call him the sofa slug. It didn’t cross my mind that he was severely depressed; he never said anything. He was in a cocoon and death was the only way out.”

Charlie’s father, Sir Mark Waller, a Court of Appeal judge, says the aim of the trust is to save lives. “We are determined to see that what we have gone through does not happen to others. We feel strongly as a family that if only we had known more we might have been able to help Charlie more. He did show signs of depression, but we didn’t realise how serious they were.

“We want to try to get people to doctors - for friends and families to realise what’s happening and to get them there. and when they are there, for doctors to deal with them appropriately.”

Depression is known as the “common cold of psychiatry” - at any time, one person in 10 may be suffering from it - but as the trust’s booklet spells out: “it doesn’t take a day off and some Lemsip to cure it”. Fifteen per cent of people suffering from depression make an attempt on their lives, and the suicide rate among young men has grown alarmingly. Depressed young men, who feel less able to communicate their illness, are three times more likely to kill themselves than women.

Sir Mark says he wants to target sixth-formers, “not to make them all feel they will get depressed, but to say simply, ‘this is a piece of baggage to take out with you into the wide world where the pressures will be greater’. We’re not saying ‘you will suffer from depression’, we are saying ‘watch out for it’.”

Only 10 per cent of people who go to GPs with depression are referred on. In an attempt to improve GP care, the trust has set up, in a joint pound;80,000 project with the NHS, a clinic in Lambeth, south London. Here, nurses specialising in depression will staff a GP clinic with links to Anthony Mann, professor of epidemiological psychology at the Institute of Psychiatry. The aim, according to Sir Mark, is for people to be able to walk in off the street and receive counselling.

The trust has also funded the research of Dr Andre Tylee at the Institute of Psychiatry into mental health and primary care. Dr Tylee, who recently became the country’s first professor of primary care mental health, says the trust’s support has been critical; among other things it has enabled him to tour Britain talking to groups of trainee GPs about depression. “We need to be equipped to identify depression early,” he says. “We need to assess people’s needs properly at the first point of call. We need to know what care is available and what are the effective treatments.” Bursaries are being made available for doctors and nurses to attend Dr Tylee’s courses.

Professor Mann, an adviser to the trust, says: “If we are seriously to address the rise in suicides we have to improve education of the young and treatment at primary care level. The Waller family are doing remarkable work through this trust. They are plugging a gap. It is very unusual for people who have been through this kind of tragedy to be so clear about what they want to achieve.”

Radley College’s website on depression: www.radley.org.ukpagesmemorialentries.html.Charlie Waller Memorial Trust, Institute of Psychiatry, De Crespigny Park, London SE5 8AF. Tel: 020 7848 0568. Website: www.cwmt.org