Did you buy something totally pointless in the sales? Then you may need professional help.
If one were to look for an example of the illogicality of human behaviour, one would hardly need to look further than the enthusiasm with which we embrace the January sales. You, like much of the rest of the country, have probably spent a good deal of the last month grumbling about the hell of shopping for Christmas: those hours spent in overcrowded, overheated environments spending like there was no tomorrow. And yet you have probably also quietly made sure that there is still a little bit of stretch left in your credit card, that free Saturday afternoon - this one, possibly - that will allow you to indulge in another explosion of the feeding frenzy that is rampant consumerism.

Shopping is great fix, especially for some reason for women. This is possibly partly to do with the hunter-gatherer differences between the sexes. Men on the whole are more focused than women on individual tasks, preferring to perform one at a time to their satisfaction; women juggle. Thus, men, when they shop, shop with a particular target in mind and lose interest when it is attained, while women take pleasure in the shopping itself. A woman shopping will generally go to all the shops and look at everything; a man will go to Burtons and buy a shirt.

The act of buying, though, gives both sexes a sense of instant gratification and considerable pleasure. Many of us indulge that gratification regularly and without worry.

But this is not always the case. Consider the words of Lucy, 55: "I get withdrawal symptoms and feel depressed if I don't go to the shops. I tried staying in on a Saturday last week and went for a long walk with my husband. We got back at 4.20pm and I was sweating. I thought 'I have to go into town' and I thought 'Well, what am I looking for? I don't need anything,' but I can always see something."

Lucy is a member of a significant slice of society whose consumption has tipped over from normal gratification into addictive behaviour: shopaholics, if you like. A recent American study estimated that compulsive shopping patterns affect between 2 and 6 per cent of the population, 95 per cent of those affected being women. Although we are all capable of impulse buying, these people regularly purchase things for which they have little need or use - Lucy, for instance has four double wardrobes and an attic stuffed with never-worn clothes - and with little or no regard for the financial consequences.

Dr Richard Elliott, of St Anne's College, Oxford, says: "Of course, it's actually no different from ordinary shopping in other people. It's just so extreme in many dimensions. And, of course, one person's problem shopping is another person's 'well, if I can afford it...'. It's a problem in terms of the frequency with which it happens and the levels of debt that can built up. Without wishing to trivialise it, Imelda Marcos may have had a problem with the number of shoes she needed to buy, but it wasn't a problem to her."

Dr Elliott, together with Professor Kevin Gournay of London University's Institute of Psychiatry and Sue Eccles of the Oxford School of Management Studies, published a paper on the subject last year and are currently half-way through a government funded project investigating it further. Many forms of addictive behaviour, shopping included, have roots in depression, loneliness, lack of a sense of fulfilment or childhood deprivations, but they were surprised to find, within these parameters, two very distinct types of compulsive shopper who they had not anticipated encountering. As well as those who need the frenzied fix of instant gratification to ward off their problems, there are also Revenge shoppers, and what they have labelled Existential shoppers.

The revenge shopper fails into a very distinct sociological grouping. "They are women who married very young to professional men and are now in or nearing their forties. They feel that their husband is treating them as a young, unsophisticated person but that they have changed and developed and now have all kinds of justification for being treated in a different way. They cannot get it from their partner, and are quite consciously hitting at him through their behaviour," says Elliott. "This is hard to call compulsive shopping, as compulsion by definition is not something that you can rationally control. These are not women who cannot help themselves. They are acting fully rationally. And one can see when they describe their situations that they feel powerless to influence their partner. This is one way of doing it."

Rachel, a 38-year-old from the Home Counties, is one such. "On average, I can spend up to pounds 200-pounds 300 a time on nothing. It's like sweetie money." A heavily indulged youngest daughter, she married a man who while frequently absent himself indulges her sprees: "Well," he says, "You were spoilt as a child and I suppose I will have to continue the tradition." She feels that he doesn't acknowledge that she has matured during the course of their marriage - with both motherhood and her own part-time career, but "I just can't get him to understand that I've changed - I just don't know what to do any more... [the shopping] is a way of getting back at him. I say, 'well, if you took more notice of me... then I wouldn't have to do it, would I?' "

Another 51-year-old woman puts it this way: "I think I was a bit child- like when we married... but, of course, I've changed over the years - and I want more responsibility and ... well... respect, really, than I'm getting." A man's wallet, it seems, is often the only place to hit where it really hurts.

Lucy, meanwhile, is an Existential shopper. Says Elliott: "These women have for some reason chosen shopping as a means of developing their skills and expressing their personality. They see it not as a haphazard rush round the shops, but as a skilled and concentrated activity... what looks on the outside like a frenetic rush, madly getting rid of money, was not that but was a search for the absolute buy". It is in a way a search for perfection. "And it gives them a sense of self, too. A sense of power. Rather than being a compulsive shopper, they have a sense of heightened skills. But, of course, they do it repetitively, so they're not fully in control of it."

Indeed, Lucy, who has often had to use savings to pay off credit cards and loans, has often bought "one of every colour" of an item of clothing. She once bought the entire Burberry range, and feels "a great sense of pride when I find that "perfect outfit"... even though it ends up either in the loft or hanging unworn in a wardrobe.

In the meantime, the stores abound with tales of crazed consumption. Peter Villasey of Harrods was a mine of hair-raising stories. "This man came in once in search of an alarm clock. We had an exhibition of antique clocks at the time, and he ended up spending pounds 250,000 in half an hour. Another customer came to buy china during the sale and walked out with pounds 60,000 worth of crockery. None of it in the event marked down. But the best recently was the man who wanted a Christmas present for his son. He picked out a Sega Gamegear computer-game consol, which sell at around pounds 100. Then he had it customised with gold and precious stones. It ended up costing pounds 55,000."

Many Harrods customers, of course, are well equipped to afford such excesses. But what of less elevated mortals? Richard Elliott believes that credit card companies have some measure of responsibility. "I don't honestly think that having credit cards makes people go out shopping, but it is certainly a facilitator."

Lloyds Access, when asked, claimed to be unable to provide any suitable case studies. When Mr Elliott approached a credit card company for funding for the current project, he "got a very sharp note back saying 'nothing to do with us. Why are you asking us in the first place?'" Strange paranoia for such benevolent organisations.

So, is there help available for those suffering from this affliction? At the moment, no. The courts rarely, if ever, refer compulsive shoppers for treatment as they do those with gambling or alcohol problems. "They tend," said a practitioner at London's psychotherapy Centre, "to see it as a moral problem rather than an emotional one. I've never heard of the courts suggesting therapy for debtors." Elliott, Gioiurnay and Eccles wish, as part of their study, to set up a self-help group or groups. They currently have upwards of 200 people on their database, and would welcome approaches from others for whom any of this rings a bell. "Most of the people on our list," says Elliott, "have come forward out of a sense of desperation. They don't just want to be part of the survey. They want some help."

If you'd like to join the self-help group, contact: Sue Eccles, School of Management Studies, University of Oxford, Radcliffe Infirmary, Oxford OX1 6ME (01865 228470/fax 01865 228471)