What happens when the going gets too tough?

Work is the third most common cause of stress in Britain after bereavement and financial worries. As the demands of modern life escalate and social support breaks down, so it increases. In Britain 6.5 million working days are lost each year to stress-related illnesses. Some staff are able to make changes to enable them to cope better. Others, however, unaware of how ill they actually are, don't stop until they literally drop.

Work is the third most common cause of stress in Britain after bereavement and financial worries. As the demands of modern life escalate and social support breaks down, so it increases. In Britain 6.5 million working days are lost each year to stress-related illnesses. Some staff are able to make changes to enable them to cope better. Others, however, unaware of how ill they actually are, don't stop until they literally drop.

At 57, semi-retired farmer, John Marks, is learning how to chit chat. At his age, one would have thought he'd have already got the hang of it. But when you've spent much of your life working 16 hours a day, seven days a week, something has to go - including the couple of minutes it takes to pass the time of day.

It came as no surprise to Mr Marks's wife, Joan, 54, that her husband eventually "cracked". ''Before he collapsed I said to a friend: 'I don't know what's going to happen, John's working too hard and getting everything out of proportion'. He wouldn't allow himself a day off. He was putting so much pressure on himself,'' says Mrs Marks at their cottage near Taunton, two miles from their 200-acre dairy farm.

Mr Marks, a hesitant, red-faced man, who insists on a pseudonym, started farming about 40 years ago. His business was a success and had even won him a number of awards. The marriage was strong, and there were no worries about their two grown-up children. But one day in October last year, the farmer simply snapped. ''Quite out of the blue I came into the kitchen, where Joan was, and just sat down and burst into tears,'' he says staring out of the window. ''I told her I had lost confidence in myself. I couldn't cope any longer, and was lost, utterly bewildered. There was a silly little catalyst. I had gone off to get 10 bags of feed and had only brought back eight. I thought: 'If I can't count between eight and 10, what can I do?' ''

He immediately went to see his GP, and broke down in the surgery. Diagnosed with depression, he was put on Prozac and received visits from a community psychiatric nurse. Mr Marks's attempts to return to work failed and his two members of staff were made partners. They now run the farm. This summer Mr and Mrs Marks moved to a cottage which overlooks flower beds. ''I was tending to exclude so much else,'' says the farmer, who is still on anti-depressants. ''I didn't realise it then, but there wasn't time to chat to people.''

He now spends his days reading, walking, and going to evening classes. ''I'm happy now,'' he says with a grin. ''We've got all sorts of plans, but at the moment it's still nice not to be doing very much. Saying 'good morning' to people when you go to get the paper is a whole new adventure. But it's still a challenge. I do have to say to myself: 'Come on, you've got to do this'. There's a lot more in the world than farming. But sometimes you can't see it. I thought I was just trying to do my job better.''

But for others, there are no grins of delight when they describe their new life away from the pressures of work. Linda Lindup, 45 - who along with John Marks appears in a Ch4 documentary, The Day I Snapped, on 4 November at 7pm - spent 20 years in social services, ended her career with an overdose. And she regrets that her suicide attempt failed.

A social worker with a physical disability team in Norfolk, her working day often finished late into the night with paper work at home. In 1995, exhausted after years of what was often 12-hour days, she was signed off sick for six months with depression. ''Before I went to the doctor I remember a couple of occasions when I drove round and round the ring road because I couldn't bear to see another person with a problem,'' she says sitting in her terrace house in Norwich, which she shares with her two daughters aged 18 and 14. At the time she was still living with their father.

Ms Lindup returned to work, but felt she was being punished by senior staff for having had time off. ''What was supposed to be a supportive environment was actually a threatening one,'' she remembers, rolling another cigarette. ''I was an experienced social worker managing projects, supervising decision-making meetings, and was suddenly being told that I wasn't filling in the diary properly. It felt punitive, and that everything I was doing was being criticised by management.''

Five months later, at the beginning of 1998, she had a row with a manager and came to the conclusion that nothing she did would ever be right for her bosses. ''I went home, got the tea ready, checked my insurance policies, had a bottle of brandy and 42 paracetamol,'' she said without a trace of emotion.

''Life was a pile of poo. Work was a pile of poo. Everything endlessly changes in social services. It's an impossible job. One minute you're responsible for thousands of pounds, and then you're told that your commas are in the wrong place....''

She was furious when she woke up in hospital. ''Deciding to die is easy. Deciding that you have a reason to live is difficult. I had thought about the children, but when you have nothing left of yourself, it's like being an empty cardboard box. You haven't got anything left to give anybody, and you think they'll be better off without you.''

She spent 10 weeks in a psychiatric hospital, mixing with some of her former clients. When she was discharged, she left her partner and moved house. Subsequent attempts to earn a living failed because of her unease at being in confined spaces. ''I lost my nerve. I had been pinned against walls, threatened with a sawn-off shot gun, and followed. You work with clients who have diseases that transmit easily with hypodermics, and they'd do things like throw them at you. Every one of those occasions is a threat. If you lose your nerve you can't do it anymore,'' says Ms Lindup laughing.

''I don't think I will ever be able to maintain a proper job again. Certainly not one that's stressful. It's really weird not working any more. Your self-identification changes. You're no longer the professional that you were. You're a housewife, and your day's about vacuuming. Or not, as the case may be.''

How has her suicide attempt affected her children?

''I think they hate me for that. The youngest one hasn't articulated very much, but certainly her behaviour has changed quite dramatically. If you don't know that the person who is your carer is going to be there tomorrow, then in that kind of situation kids test out. I have overstepped a spiritual, practical and emotional boundary. There's the knowledge that you can trust nothing, because anything can be taken from you at any moment. And for children, that's quite devastating really.

''There has been lots of questioning in terms of 'why do you want to leave me?' It's an impossible question. All you can do is keep on being available, really.''

Does she regret that she didn't die? ''Oh God yes! I think it's hard to find reasons to carry on living. I like beginnings and endings, and what I thought would be an ending wasn't. And it wasn't a beginning either, it was a change in direction which I didn't want. I wanted an end.'' The only thing that prevents her from taking another overdose is the fear that it may not work again. She is still on anti-depressants.

Ms Lindup spends much of her time in the garden, looking after the two goats she has just bought - an incongruous sight and sound in a housing estate - and a family of guinea pigs. Going out is a problem. ''There are days when I don't know whether I can go into the supermarket. I might leave the house to go there, but if there are too many people in there, I can't physically go in. I can't bear for people to be too physically close anymore.''

How does she feel about the way she has been affected by her job? ''I'm angry with the system. I don't think there was anything that I displayed that wasn't identifiable in terms of a stress reaction at work. And what are managers for, at the end of the day, if they're not there to help identify with you when you need to stop?''