Many women in apparently calm, happy, stable marriages are astonished to find that when their husband reaches the ages of 40 or 50 he undergoes an inexplicable and shockingly sudden personality change. It often involves a seachange in his habits and preferences and very often there's a girlfriend attached to the process as well.

He may be the very last guy you'd think would have a mistress and yet the evidence is clear and often he tells his wife that he's in love as never before.

When midlife crisis hits a man he is apt to forget or deprioritise his children, show a total lack of respect for their mother, and generally behave as though he is the centre of the universe and entitled to every new and exciting experience he can lay his hands on.

His former concerns and values are completely jettisoned in favour of himself, his body, his car or motorbike and his girlfriend.

Women who have been through this unexpected ordeal are likely to have heard more or less the same speech: "I love you (kind of) but I'm not in love with you. And I need time and space."

After which, typically, the midlife crisis male leaves home and shacks up with an unsuitable girlfriend for a year, two years, or longterm.

 As a wife or long-term partner, and possibly mother of his children, your first instinct is likely to be that he needs help. You start frantically trying to understand what on earth has happened to him. How can he possibly want to leave home, leave you and the kids, for someone he hardly knows? It's not just incredibly shocking; it also seems that he's lost his mind.

The crisis may be accompanied by other reckless projects too: he wants to sell the family home, or move to another continent where he has no income and knows not a soul, or he wants to live on a tiny island or on top of a mountain...

Whatever he comes out with as the ideal and obvious solution it's likely to make your hair stand on end.

It's almost certain to involve leaving you and leaving the kids.

And he simply won't understand that you (and they) are turned upside down by his decision.

 When this happens - and it's incredibly common - your life will be turned upside down.

Although your initial instinct is to help him, you need to forget that - fast. It's not that your feelings are wrong - they're natural - but he's simply not listening. In midlife crisis, a man is entirely focused on himself, his desires and his huge sense of "entitlement" to have fun and act young again. You can try to remind him of his responsibilities and loyalties but he won't hear you. You'll be wasting precious energy that you need to turn towards yourself and your family. He won't think there's anything wrong at all with abandoning his wife and kids for a woman he didn't even know a week last Wednesday.  

The behaviour of "Rolling Stone" Ron Wood is typical of (late...) male midlife crisis. Though he's in his sixties, he suddenly hit a period where he felt he absolutely had to try to regain his youth. For him, the blindingly obvious answer was to run away from home with a Russian bar hostess 43 years his junior. Obvious, no? (Roll eyes.)

For all that his wife and children and friends and everyone else he previously trusted might have told him he was being a five star idiot, it seemed like a fabulous idea to deluded, wrinkly Ron. With a girl young enough to be his granddaughter he could - temporarily - imagine he was young again, handsome and desirable. Although his family and the world at large saw very clearly that he was a silly old man being taken for a ride by a very young gold-digger, hapless Ron, in the grip of an acute late MLC, deluded himself that he was in  love. Even sillier, he imagined the young girl was with him for love rather than money.

The point is that once midlife crisis hits a guy, he has to go through it even if it involves leaving home and making a whole raft of other absurd decisions.

You can no more reason with an MLC male than you can reason with a recalcitrant adolescent. They're in the grip of a very powerful physical and emotional change and your best bet, however hard it may be to do, is to stand well back and leave them to get on with it.

Midlife crisis is nothing like midlife transition. Many people evaluate their lives, progress and achievements between the ages of 40 and 50. And many go on to make rational, planned changes. Midlife crisis, in contrast, is marked by dramatic personality change, reckless changes and destructive approaches to home and family and often to job and career as well.

See my other pages for more detail on the problems of MLC and leave a comment or question if you wish.

If you are dealing with an MLC man in your life, there's a forum which you will find invaluable: www.midlifewives.com

Here you'll find an astonishing resource of description and comment which will give you insight into an otherwise apparently inexplicable phenomenon.

Good luck, and leave a comment if you'd like to discuss your experience of dealing with MLC.