It's all rather counter-intuitive. Here we are living longer and longer, yet according to a survey published by Relate and Talk Talk, we are having our midlife crises younger and younger. As couples start families later and their careers peak earlier, many men and women are already feeling anxious, stressed, lonely, generally useless and washed up by their late 30s and early 40s, rather than in their 50s.

If you haven't made prime minister or leader of the opposition by your early 40s, then clearly you are an abject failure; and if you have, you will be totally stressed out and it's all downhill from there on anyway. Call it a narcissistic breakdown or midlife crisis, here's a handy 10-point guide to survival.

1. Remember the alternative

You are still alive. That's got to be something of a result. And if you should suddenly drop dead, at least you can't moan that you died young. Well, not very. Which brings me to . . .

2. Don't presume every cough is lung cancer

So don't go to the doctor every time you have a symptom that persists for more than 12 hours. It doesn't make you very popular with your GP and it's not in the slightest bit helpful. Because once one fatal illness has been eliminated you'll go home to find another fatal illness that matches your symptoms on Wikipedia. And eventually you will find an illness for which there is no definitive diagnosis. Except post mortem. I speak from experience. I remain the only person to have recovered from BSE.

3. Don't have an affair

Yes, your partner might not be quite as gorgeous as he or she once was, but take a look in the mirror. You are no oil painting yourself. So don't embarrass yourself by hanging out with people a lot younger than you. Or by imagining that they fancy you.

4. Don't worry obsessively about work

If you have got your eyes set on a particular job, it's almost bound to end in disappointment. Remember David Miliband? These days you can count yourself lucky to have any job. And if you don't have one, try to take some pleasure in the fact that loads of people you know will be losing theirs in the next few years. Schadenfreude can be a handy therapeutic tool if used wisely. Talking of which . . .

5. If you are thinking of therapy, don't go in for analysis

You will start off having one session per week. After six months you will think you're getting nowhere. Your analyst will tell you this is because you have deep commitment issues and you need two sessions a week. You will reluctantly agree, if only to avoid spending every session talking about why you don't want a second session. After a further six months, you will again realise you are going nowhere. Your analyst will again point out that you have really deep commitment issues and what you need is three sessions per week. You will agree for precisely the same reasons as you did before. Six months down the line, she will want to up it to four sessions per week. At this point you will be a financially and psychologically broken man and be admitted to a mental hospital. When you eventually get out, your analyst will give you a bill for the sessions you missed when you were in hospital. Again, I speak from experience.

6. Don't transfer your neuroses on to your kids

Stop getting worked up about the extra maths tutorials, the football coaching and the music lessons. Face it, they almost certainly aren't going to get into Oxbridge, play professional football or be a world-class concert pianist. They are just bog-standard kids: much the same as everyone else's. What they really need is for you to back off and let them mooch around getting bored rather than being ferried around in search of over-achievement. There is a reason your kids have limited talents; it's because they are yours. So just accept it. And them.

7. Don't go buying midlife toys

Nothing screams complete idiot more than the sight of a middle-aged man with a load of expensive gadgets. Not so long ago, you could identify these men by their sports cars or motorbikes. This year's midlife accessory is the fixed-wheel racing bike. You are not a courier; you are an overweight man whose reactions and balance aren't what they were. Ride one of these and you will certainly end up in A&E. Where the doctors will try not to snigger as they cut off your Lycra before wheeling you into surgery.

8. Turn off your BlackBerry

If not in the evenings, then at least at weekends (if Gucci CEO Roger Polet can do it, so can you). And it may be hard to believe, but your family would quite like to have the chance to ignore you rather than always be ignored by you. Yes, there's always the chance that key email telling you you're sacked will arrive while your BlackBerry is switched off. But you'll find out soon enough on Monday morning, and at least you will have had a nice weekend.

9. Make time to go out

I know you're knackered and just want to put your feet up once the kids are in bed, but try to go out with your partner – or at least your friends – once a week. At best, you can talk to one another and you might even remember why you first fancied each other. At worst, you'll just fall asleep over pudding.

10. It will get better

It may feel like the end of the world, but one way or another – oh, and never rule out Prozac – your feelings of midlife existential futility will pass. The bad news is they will be replaced by much worse feelings of later-life existential futility when you reach 50. Again, I speak from experience