Not everyone who shoplifts is a simple thief. But why does kleptomania affect mostly women - and what is the link with eating disorders? Sarah Boseley investigates

Hilary had no reason to steal. But reason didn't come into it. She was a professional, middle-class woman with a good job. And she was a compulsive thief. This is how she describes the beginnings. "My first dip into the murky world of theft had been a spoon from a cafe. As spoons go it was nothing special but somehow the act of taking it seemed to soothe me. I was hooked. Other small, ridiculous things followed but soon my compulsion was a hungry monster, demanding a daily fix of more dangerous booty.

"The momentary fix was delicious, for the minute or so that it lasted. Then came the guilt. Nights were spent lying awake, crying and pleading with myself to stop. The thought of what I was doing, what I had become, repulsed me. The inevitable consequences of losing my job, devastating my family and going to prison were all terrifying but the next day all that was forgotten and I was off again. "I was driven. Spare moments in the office were spent scouting for neglected belongings, nights out in bars meant a constant vigil for any abandoned coats in dark corners. It was my grubby secret. My flat was a web of hiding places for things I would never want or use."

Hilary had become a kleptomaniac, stealing not out of covetousness but for the fleeting relief it gave her from tension building in her head. It is a psychiatric condition better recognised in the US, where the actor Winona Ryder was arrested in December 2001, after being caught in Saks Fifth Avenue on the sort of camera she would never have posed for, stuffing clothes she hadn't paid for into her bag. She told the court, which convicted her of theft, that she was getting into character for the part of a kleptomaniac in a new film.

Kleptomania affects mostly women and is hard to distinguish from plain criminal shoplifting. But frequently these petty thieves have underlying depression and have suffered from eating disorders - bulimia or anorexia nervosa. None of that may be picked up when they are hauled off to the police station or brought to stand in the dock months later.

So it is more than likely that many women with this psychological disorder - it gives them a marked sense of relief as they scurry from the department store with a pillowcase under their coat - are now in jail, their lives destroyed by the stain of criminality.

Researchers at Stanford University in the US, who are studying whether the impulse to steal can be controlled by antidepressant drugs, believe up to 1.2 million Americans may suffer from kleptomania. Of all shoplifters, they say, probably around 5% do it because of a psychiatric condition. That means it is far more likely that a woman with kleptomania will fall into the hands of the criminal justice system, rather than the mental health system - especially in the UK where the condition is barely even acknowledged.

Richard Stern, a consultant psychiatrist with the private Priory clinics, says that, essentially, women with kleptomania will only be diagnosed if they have a smart lawyer who is aware of the condition and willing to get a professional opinion. "They get punished if no one thinks of the possibilility that they might be ill," he says. Few shoplifters are asked whether they have ever in the past suffered from bulimia or anorexia, or shown any other signs of mental distress.

Kleptomania, says Stern, is a bad name for it. "It is not a mania at all," he says. "I think that the behavioural condition of shoplifting is better because it describes what they do. The question is why. Certain types of shoplifters are known to suffer from certain psychological problems, of which the commonest is depression.

"There is a category of young women who take things from shops as a manifestation of their depressive illness. What happens then depends on who deals with them. It depends on whether the lawyer considers the mental illness aspect of it or not."

Poor women and women who may be depressed or beleaguered are unlikely to have a lawyer cute enough to call in a psychiatrist. And a defence of kleptomania is only really likely to convince the court if there is no financial need to steal. Stern believes that UK psychiatry is "probably only seeing the tip of the iceberg".

Jeremy Coid, professor of forensic psychiatry at St Bartholomew's hospital in London, says doctors have to be extremely careful in making the diagnosis. "You occasionally get an individual trying to convince you that they are a kleptomaniac when in fact they are a regular thief."

But there is plenty of evidence that this is a genuine psychiatric condition for many, who do not need or want the things they steal, but seek the feelings of relief and gratification that follow the theft. Coid talks of a kleptomaniac who was trying to come off Valium:"It's almost easier to get patients off heroin than Valium," he says. "She was of good character and middle class. She found that when she was stealing on two occasions from the supermarket, the excitement somehow made these unbearable symptoms feel a bit better.

She waited outside for the security guard to catch her. She also had depressive symptoms, but the main thing was what she called the 'woolly things in her head'."

Kleptomania was first officially identified and given a diagnosis in a French textbook in 1838. It was originally thought to be one of a number of single disorders of the mind - the monomanias - along with nymphomania and homicidal monomania. but that thinking has gone out of fashion. It is now considered to be an "impulse control disorder" in the US, like pyromania, tricotilomania (where the sufferer has the urge to pull out hair) and pathological gambling.

Some argue that many of the depressive and anxiety disorders are artificially separated by psychiatrists and drug companies into new syndromes for which they can re-market their existing drugs. Many patients have mixed disorders. Some would say that a bulimic woman who is a compulsive shoplifter is manifesting her mental turmoil in more than one way, rather than suffering from two separate disorders.

Coid thinks kleptomania is more of a symptom than a disease that exists independently of any other psychological condition. "It makes them feel better. It is usually part of extreme misery and depression.

"The definition in DSM IV (the Diagnostic and Statistical Manual of Mental Disorders - the psychiatrist's bible) talks about the relief of a feeling of tension beforehand."

Doctors in the US have been treating diagnosed kleptomaniacs with mood-altering drugs such as Prozac and Seroxat, on the presumption that it could be triggered by changes in the levels of serotonin in the brain, which is what they think happens in depression. Psychological counselling, to get at the underlying causes of unhappiness, is more likely to effect a long-term cure.

Hilary thinks the courts are more aware that shoplifting may have a psychological root. But, she says, "Society is a different matter. There is always a fear that too much psycho-babble when it comes to crime will lead to letting the culprits off too lightly. In the end, though, without more awareness, it will be society, not the thief, who will pay.

"Above all, there is the human cost: the pain and shame for families like mine who will never really be able to explain or understand why their lovely daughter ended up here, in a cell."