It was Julie McNamara's job to help the man who had just sloped into her office, shoulders sagging, late for an appointment. She was a therapist and he was one of her clients. 'He was sitting there with this sulky expression,' she says, with a wry laugh. 'He just looked so negative. I looked at him and said, "You think you're having a hard time?" and told him to go to bed with a hot water bottle. I couldn't have given a shit what he had to tell me that day. That was burnout for me.'

Looking back, the symptoms were all there. She had been feeling the kind of exhaustion no amount of sleep can relieve. She was working incessantly but feeling as though she was getting nowhere. She had a constant sense of isolation. It isn't hard to see how Julie McNamara broke down. She had suffered an incredible 11 recent bereavements - including the death of her father. Her job for Hackney Council was emotionally draining, stressful and poorly managed. 'I give everything I've got to a job and I felt set up to fail long before I cracked,' she says. 'The poor sods who came to my office didn't get many chances and I really wanted to help them. But I had become cynical because the budget was so small for our dreams and visions.'

It took two years for McNamara, now 42, to recover fully. 'After that I learnt to say no,' she says. 'I learnt to look after myself because if I didn't, I would have nothing to give.' She pauses, and laughs again. 'And I also learnt that I didn't want to work in mental health any more.' Today McNamara works three days a week at the London Disability Arts Forum and uses the rest of her time to run writing courses, and perform in public, activities that make her happy but were previously squeezed out by the demands of a demoralising job.

A new book, The Joy of Burnout, by psychologist Dr Dina Glouberman, suggests that burnout is a positive thing. She believes burnout is what happens when we ignore 'the soul whispering' against an unhealthy job or relationship. 'Your heart has gone out of something but fear, often of the loss of your sense of identity, drives you to work even harder or give even more,' she says. The book is endorsed by author Sue Townsend who writes of four burnouts in her own life, marked by illnesses including TB, a heart attack and sciatica, which generally occurred during angst-ridden periods of overwork, when she felt she was allowing herself or her work to be compromised.

Glouberman's argument is that burnout, usually seen as a disaster, is not the end but a new beginning, though, she stresses, it is preferable that people transform an unhealthy situation before they are damaged. 'I'm suggesting that, at the first symptom, you stop and listen,' says Glouberman, who suffered a burnout of her own in 1989. It is a provocative notion - that through the pain of burnout, human beings can undergo some kind of rebirth.

It was with the caring professions that burnout - a term coined in the late Seventies by psychologist Herbert Freudenberg - was originally most associated. But the term is now almost synonymous with the corporate world. Last week a survey, UK Wealth Watch, reported that one in three people on salaries of more than £60,000 wish they had put happiness ahead of earning money. Research from the UN International Labour Organisation backs up the findings. It surveyed five countries - Britain, the US, Germany, Finland and Poland - and discovered that workplace stress, burnout and depression is spiralling out of control. The report warned that anxiety levels will rise with the increased competition and uncertainty generated by globalisation.

Downsizing, layoffs, mergers, short-term contracts and the push for higher productivity are taking their toll. Overall, the survey found one in 10 workers suffering from depression, stress and burnout. The UK comes out particularly badly, with three in 10 employees suffering mental-health problems. It is estimated that 80 million days a year are being lost in the UK to stress - a financial burden of £5.3 billion.

Professor Andrew Kakabadse, of Cranfield School of Management, believes some people still refuse to acknowledge burnout because of its association with mental breakdown. 'But burnout isn't like that,' says Kakabadse, who sees it not as a crisis point, but as a state of being. 'People can be burnt out for two or three years and they just carry on working. Most don't leave their jobs but their relationships and health suffer.' For Kakabadse burnout is essentially overwork, and is 'a social not a mental-health problem'. He says stress is worse in countries with Anglo-American business models where rationalisation and redundancy mean far too few people doing far too much work. 'If you go to Germany, Scandinavia or parts of France, there is less burnout,' he says. 'The UK has the longest working hours in Europe. Around 80-90 per cent of executives experience some kind of burnout in their career, and most have two.'

Despite figures that suggest a near epidemic, some still see burnout as nature way's of weeding out the weak. Glouberman insists, however, that burnout is likely to hit the most creative, hard-working and committed people. And psychology professor Christina Maslach, from the University of California, Berkeley, one of the world's leading burnout experts, argues that companies ought not to scapegoat employees but look to the environment they expect people to work in.

Management consultant Elizabeth, 37, agrees (she prefers anonymity because she fears any perception that she 'couldn't hack it' will torpedo future job opportunities). Until last year, Elizabeth worked for one of London's top management consultancies. She was earning six figures for the first time in her life, and promotion and partnership beckoned. But she was first to the door when a redundancy programme was announced. 'I was with the company for three years before I got so unhappy,' she says. 'Until then, I don't think I had had time to reflect much on what was happening. I was just rolling from one project to the next.'

But the pace began to take its toll. 'There were a lot of tight deadlines and it could be 4am before you finished at the office, and you worked many weekends. The highest standards were always expected. It was relentless and utterly driven. It relied on you wanting to prove yourself over and over again, against other people.

'I became manic about the little time I did get off. I ended up drinking far too much, and partying too hard. And then I would be so depressed at weekends that I couldn't even get out of bed.' Elizabeth's mood swings weren't unusual. On smart-suited weekdays, manage ment consultancy looked quite glamorous. But weekends could be sad affairs. 'I remember one colleague whispering to me that she'd spent her entire weekend in her dressing gown just staring at videos,' says Elizabeth. 'That was how it was. One moment you didn't even want to pick up the phone and then you were getting drunk and out of order. It just wasn't the person I am.'

It was Elizabeth's moth-balled private life that bothered her most. She had not had a boyfriend since she joined the firm. 'I began to worry I was never going to meet anyone,' she says. 'A lot of people did leave, but I was so ground down by then that I didn't have the confidence. It was the sort of environment where insecurities were drawn out and played upon. There were a couple of partners who were very psychologically aware. It wasn't exactly manipulation or mind games but in that area.'

The redundancy programme - offering a year's salary - came just in time. 'I didn't have a nervous breakdown but I was on the edge,' she says. Elizabeth doesn't blame everything on the company. 'I colluded with the system,' she says. 'Its measures became my measures of success. And I did feel like a failure when I left. A lot of people thought I was mad to give up my salary.'

Lawyer Helen Quinn, 38, also left a lucrative post with top City law firm Clifford Chance last year. She had worked there for over a decade and her gradual disenchantment with work chimes with Elizabeth's. Overnight and weekend work, during multimillion-pound property acquisitions, had seemed exciting in her twenties. Now she dreaded the unexpected file dropping on her desk. 'I became increasingly disillusioned with the ethos of the big corporate firm,' she says, adding that the lack of female law partners in City firms is testament to how little the environment suits women. 'I didn't become a gibbering wreck, but there were days on the train to work when I thought shall I just stay on until Barking, or just go round and round on the Circle line? I was almost 40 and didn't want to do this for the rest of my life.'

Quinn moved on before unhappiness caused her any ill health. When James Bennett ran into trouble as the new marketing director for a division of accountants, he was less fortunate. Bennett was a 30-year-old wunderkind when he was head-hunted for a Price Waterhouse job but he found the culture of the large corporate organisation difficult.

'I felt I was failing,' says Bennett, now 36. 'I just worked harder and harder thinking it would come right. I became really ill and ended up in the hospital for tropical diseases with some viral illness they could not identify. When I tried to go back to work, I was utterly exhausted. The company sent me to all sorts of psychologists and doctors and eventually chronic fatigue syndrome was diagnosed and I took three months off.'

Bennett has no doubt stress caused his illness. The 'failure' at Price Waterhouse played on deep insecurities. Bennett's dyslexia went undiagnosed at school and he left at 16 with no qualifications, believing he was 'thick'. After starting out selling windows, he set up his own record import company, and did an MBA, after which he was successful in his first company marketing director's role. But when things stalled at Price Waterhouse, the self-doubt flooded in. 'I was the young high-flying executive, with a bright future and the world was my oyster,' he says. 'I felt if I failed there, I had failed at everything.'

Bennett was eventually given a generous severance package. And, like Elizabeth, he takes some responsibility for what happened. 'It's too easy to blame the employer,' he says. 'While an employer has responsibilities, an employee also has responsibilities for getting the work-life balance right.' He says the crisis taught him that too much of his self-esteem was wrapped up in work.

Life coach Fiona Harrold helps put the burned out, and the poised-to-burn-out, back on their feet. 'I think burnout occurs when people have gone six months past the time when they should have made serious changes to their lives. It is the body saying this is enough, I don't want to do this any more.'

Harrold says that when the all-consuming jobs disappear, many clients find that even huge payoffs fail to take away the painful sense of failure. 'I have one woman who got an astoundingly high severance from the City after becoming sick,' says Harrold. 'She had a long successful career and yet she feels like a failure. People get so caught up in their work worlds that they lose perspective.' Harrold is tough when it comes to getting the burnt-out moving again. She suggests her clients think of Africa, or simply take a taxi down to Peckham, south London when they are feeling sorry for themselves. And she is absolutely uncompromising in her belief that none of us - even those saddled with a mortgage, a nanny, and three sets of school fees - needs to stay in jobs we have come to hate.

Glouberman also connects illness and burnout and Sue Townsend says she sees something 'significant' in the way her four periods of illness, including her recent blindness, forced her to take the rest her relentless drive and manic working will not allow. Of the chronic sciatica that struck her at 49, Townsend says: 'The only way I could get relief for myself was for my body to break down. It was the only way I could get rest without guilt... I have a facility to carry on where other people would've stumbled at, say, the third hurdle. I carry on to the end with my legs broken, ridiculously neglectful of myself.'

Harrold also sees the link between burnout and illness, and warns that burnout's victims are getting younger. 'Years ago, it was the 43-year-old businessman and his first heart attack. Now I have very unhappy men in their late twenties coming to me,' she says. 'These are serious achievers, who have been on the treadmill since the age of six, getting top marks from prep school right through to university. And they say, "Look at me, I've turned into a suit, and it isn't me."' Harrold says many clients make changes to their lives in time. 'But sometimes things have to get so bad they couldn't get any worse. Sometimes people have to get sick.'

Harrold's client Nicola Moule was 26 when she developed vasculitis, a rare auto-immune disorder. Doctors are uncertain about its causes but both women are sure that the stress of working as a marketing consultant in London played a part. Moule was struck down more than three years ago and did not work for a year. 'I think it is possible that my subconscious was telling me that what I was doing didn't suit me,' says Moule, 'I am so much healthier and calmer since I got off the treadmill and moved down to Cornwall.

'In London I had been putting too much pressure on myself to be successful (whatever that is ) and trying to keep up with London life - whatever that is. In London it's all about the right clothes, going to the right places, even drinking the right drinks. There was a lot of pressure but you just get on with it, don't you? How many people have time to stand back and take a look at their life?'

Moule's sickness began with a cold that wouldn't go away. Before long, exhaustion set in. 'I didn't even have the energy to watch TV,' she says. 'I just kept trying to keep going.' She was finally diagnosed with pneumonia. Drugs helped her recover, but Moule believes a change in lifestyle played a large part. She did try to resume her London life but felt too exhausted most days to do much more than shower, and after four months she moved down to Cornwall. 'I had to move away from the temptation of doing too much all the time. And I think I had to find something that made me happy to get better.'

Philip, 48, is a businessman who also prefers anonymity. He's survived two periods of chronic fatigue with burnout. The first illness occurred in 1991 when he fell into £500,000 of debt after buying a country house before finding a buyer for his London flat. Philip ended up with a bridging loan as interest rates surged to 16 per cent. Then an import deal he had devised to solve his financial problems collapsed, adding to his debt. 'I couldn't declare myself bankrupt,' he says. 'It is just not in my psyche, so I worked 18-hour days, six days a week, for two years to pay off the debts.' It was a period of siege. 'I worked from home, living in tracksuit and flip-flops. I avoided my clients, except on the phone. I felt I had got into the mess and I had to get out of it.' He spent only a few hours a night in bed and even then he couldn't sleep. 'I would end up just looking at the ceiling,' he says. He collapsed immediately after the money was paid off.

Philip had to take three months off work but his health recovered, his company grew and so did his personal wealth. Then in 1997, he had another collapse. This time there was no financial crisis but again he was working too hard, trying to build up his business. 'My father spent his entire life working to make other people rich,' he says, 'so my whole self-esteem was tied up with being financially independent. It was me who put me under pressure.'

It took six months for Philip to recover, but he believes he learnt a lesson this time. He has not had to make a huge change in his life, just develop a change in mindset, suggested by Harrold. 'Before the burnout, I felt I was the head of a household with 14 people [his employees] to support, and I had started to resent my employees. I try to see the business more as a partnership now.'

James Bennett says that one of the great misconceptions about burning out is that you then have no option but to buy a croft, and grow your own vegetables, far from the commercial cut and thrust. 'People assume burnout means complete change,' he says. 'But you might be in the right career but have the wrong attitude.' Since leaving Price Waterhouse, Bennett has created a successful international conference company, the European Technology Forum. Price Waterhouse is one of his customers. Bennett says burnout removed a deep-seated terror. 'I no longer have the fear of being on the scrap heap,' he says. 'I know that if this business doesn't survive, I will.'

Nicola Moule is also back in business. She now runs a marine engineering company with her brother and a PA service. 'I still work as hard but I'm enjoying it because the work suits me better,' she says. Cornwall also agrees with her. 'I'm earning an awful lot less but here you can just walk down a beach and sit on a rock. It is better that being on a Tube full of sweaty people and a life that goes along at 110 miles an hour.'

Philip is still running his business, but is making time for aromatherapy massage and acupuncture, therapies he would have once considered 'poncey'. He also recently married for the first time. Elizabeth has also made changes and 'created balance'. She now has a partner and they are trying for a baby. She has spent the past year visiting neglected friends and relatives making up for the three-year 'deficit' in human relations. But her redundancy money is running low and she is starting to develop her own business. 'There's only so long you can sit on the couch,' she says. 'But I would rather work for myself now. The corporate world is always looking for fresh human beings to work to death.'

For Helen Quinn, leaving her job has meant more time at her Normandy holiday cottage. It has also meant a 'quite scary' period trying to decide what to do next. It is sometimes easier to know what you don't want to do, than what you do. 'Leaving the job was like suddenly being cast adrift,' she says. 'Suddenly there was this blank canvas. I felt I had no role, no external recognition of who I was.' But it has allowed her to see the wood for the trees. She has discovered that it wasn't law she had gone off, just the kind she was practising. 'I was so ground down I had lost sight of what I liked and was good at,' she says. Quinn is working as a consultant to a high street solicitors' practice in east London: 'Some people in the City would be snooty about that but I wanted to do something more community-based.'

And what of burnout's joy? It seems almost masochistic to connect all the pain, confusion and misery of burnout with joy. When we read of people taking years to recover from a life-shattering collapse, it seems to be taking the desire to see the positive to ridiculous lengths. But Glouberman says burnout is the body's way of putting the brakes on. 'We won't stop, so burnout stops us,' she says. Burnout, Glouberman insists, can be the beginning of rediscovering the joy of life itself.

James Bennett would stop short of using the word joy for his post-burnout years but he can certainly see the positive in what happened to him. It fundamentally changed the way he thinks about himself, he says, and gave him the opportunity 'at a relatively early age' to reassess what is important in life and do something about it. And, rather neatly, in his case at least, burnout has led to greater material success. 'What can seem like a disaster, can be the start of a great opportunity,' he says.

For Julie McNamara, too, burnout had very positive consequences. 'I called what I went through a breakdown at the time but now I'd call it a breakthrough,' she says. But not everyone is convinced. Philip will have no truck with it at all. 'The only positive is that I've learnt how not to get like that again,' he says. 'Most of all, I just wish it had never happened to me.'

Signs of burnout

· You are exhausted all the time, no matter how many hours you spend in bed

· A sense of isolation from other people, and even from yourself, to the extent of becoming a virtual recluse

· Ineffectual, no matter how much work you put in

· A feeling of emotional deadness

· Chronic anger even in the previously mild mannered

· Loss of empathy for other people's problems even when it is your job to be empathetic

· Feeling of being trapped

· Increase in cynicism

· Loss of sense of humour

· Loss of sex drive in a relationship but increased interest in casual sex and other activities that can become addictive such as drinking, shopping and internet chatting

· Increase in physical problems including back and heart pain, headaches, frozen shoulder, chronic fatigue, adrenal and thyroid problems, irritable bowel syndrome, post-viral illnesses, viral meningitis and even heart attacks

· Rising dislike for yourself and others

&#183 To order a copy of the Joy of Burnout by Dr DIna Glouberman, for £8 plus p&p (rrp £10), call the Observer Books Service on 0870 066 7989