FRANK DOBSON is taking time out from his mayoral campaign because he is overtired and stressed. It can happen to the best of us. In a world where we are encouraged to believe that every opportunity for more money or power has to be grabbed, there are an awful lot of people needing to "spend time with the family".

Round holes? Square pegs? It can seriously damage your mental health. As a student I worked for Woolworth on the pick `n' mix stall. Arguably I was even more reluctant to do this job than Dobson is to run for Mayor. I could not smile on demand. I had no interest in raspberry truffles. After three weeks I went mad, yes literally. My mother had to tell them I wasn't going back.

Luckily Woolworth was equally glad to be rid of me. But it's not always so amicable in a career-driven society, where sense of duty, ambition, peer and boss pressure and lack of assertion stop us making the right choices at work. We agree to something we don't really want because we feel we have to.

The results are cataclysmic. More than a billion days are lost to stress at an estimated cost to companies of pounds 10bn. To say nothing of faltering relationships - one couple went into therapy when work commitments resulted in the husband not knowing the name of the family dog.

"A super salesman gets promoted because he's the best salesman," says Ben Williams an Edinburgh-based psychologist. "Because it's more money and the next stage of progression, he says yes. But he hates being a manager and he is bad at it. He does a poorer job and is a loss to the company as a result of that."

"It's a brave thing to say to your boss `I know my limitations, and I don't want to take on more responsibility, I don't need more money'," says Stefan Stern, features editor of Management Today. "You may have other ambitions - ambitions for family life, ambitious to avoid being ill through work stress."

Your boss may not accept that you do not want a better car and more money in return for your life. But do not cave in. You will be better somewhere else.

"I was pushed into an academic career," admits Laura Wood, 37. "It never really excited me, but I just kept going through the system. I was a lecturer for five years when I fell ill. I had a flu thing which developed into ME. My doctor asked me if was depressed. I realised I hated academia. I wanted to work in a more dynamic environment. As soon as I'd made that decision I started to get better. I now work in the personnel department of a huge corporation. It's not what my parents wanted for me but I'm much happier."

"I get a lot of 50-year-olds coming in saying `I never wanted to be an engineer'," says Ben Williams, "people who took the wrong direction and struggled on - it's very sad. Democrates said, `To live badly, is not to live at all but to take a long time dying'. It's not worth it."

Don't spend the next thousand years (well it'll feel like it) in the wrong job. "Think of your career as a computer," says Ben Williams. The hardware stays the same but you frequently need to update the software package - whether you are Frank Dobson or Fred Bloggs.

If you're in the wrong job...

Don't panic. Carve yourself a piece of undisturbed time and ask yourself, "What would I do if I knew I would not fail?" Within this question you need to think "SMART", explains Williams. "Your ambitions need to be Specific, Manageable, Acceptable to the rest of your life, Realistic to your intellectual, physical and spiritual situation and Timed - always set a deadline.