Katy Guest: Yes, he's fat, bald, impotent and sad. And I wouldn't have him any other way

Can't we let men know that slowing down and being silly are natural, instead of telling them they're all bleating hypochondriacs?

The verdict just announced by the New England Research Institute that the male menopause is nothing but a figment of the ageing male imagination seems harsh, to say the least. Professor John McKinlay, who has made this proclamation, says there is absolutely no hormonal explanation for the effects of middle age on men. "No, you do not have a medical excuse," he is effectively saying. "You are just fat, bald, impotent and sad. And it's nobody's fault but your own."

We all like to have the luxury, just occasionally, of blaming our failings on our hormones. From time to time (or once a month, if we're honest), half the population will suddenly and with no discernible reason become clumsy and stupid, blame it on their boyfriends, burst into tears and weep, sporadically but inconsolably, for the rest of the day. However predictable these Mr Hyde spells are, there's always a hideous moment when you think you really are that hopeless, before the penny drops. Realising you're not in fact an emotional basket case and all will be better in the morning is a palpable relief. And, let's face it, can any of us honestly say we've never chalked one up to PMT when there was just the teeniest chance we were actually being genuinely pathetic?

In denying "manopause" we are comprehensively crushing men's last hope of having their own excuse for those occasional, forgivable lapses into patheticness. And there's nothing wrong with having an excuse. Wouldn't we all go out in ridiculous leather trousers and blow eye-watering amounts of money on wide-screen TVs if we could confidently insist we were genetically programmed to do so? Can't we just let men believe that slowing down and being silly are just natural physical responses to getting old, instead of telling them they're a bunch of bleating hypochondriacs who need to pull themselves together, do a bit more exercise and stop drinking so much beer? What's to look forward to about middle-age if you can't write off the Volvo, buy a Fender Stratocaster and embarrass your sons by flirting with their girlfriends? This study has taken the fun out of half of life, for half of the population, and that's no good for any of us.

All over the country this weekend, disappointed men of a certain age will have been looking defeatedly in the mirror, removing their violet-tinted contact lenses, digging out the horn-rimmed bifocals and dropping the hair-thickener in the bin. Mystified charity- shop employees will be drowning in customised leather jackets and too-tight jeans, while hairy bikers outside Kawasaki showrooms will have witnessed the bizarre sight of line after line of disillusioned men queuing to return their motorcycles and jet-skis, with goodbye flutters of their sensible white hankies, and weary sighs. And that is not the worst of it. Sooner or later, subscriptions to GQ will all have been cancelled, the exotic underwear shop Agent Provocateur will have gone bankrupt and tumbleweed will be blowing through our casinos. No good can come of men admitting defeat and sloughing off the gaudy late bloom of the midlife crisis. Only slipper manufacturers and the Discovery Channel will benefit. Middle age will become a greyer and more tedious place, for everybody.

Being serious, it is satisfying to see the drug companies caught out in their old trick of persuading us that we are ill so they can sell us drugs. Nobody wants to see a world where more and more so-called diseases are invented to con us into spending money on curing them. So perhaps it is time for us to put the battle of the sexes aside so we can concentrate on defeating a common enemy. Women should own up to men about the way they deal with their own personal crises, hormonal or otherwise. We have to spread the word: self-medication is the way forward.

Reaching for the testosterone gel is not the answer. Just as women turn to food, alcohol and ridiculous shoes when the sulks strike, so men should spend as much money on Buffy the Vampire Slayer videos and hair colorants as it takes to forget that they are getting old. They will soon start to feel a lot better. It's vital that we don't let the scientists get away with sticking pins into all our neat excuses. Or they'll be announcing that there's no such thing as PMT next. And then we'll all be in trouble.