Yvonne's tortured mind used to be her biggest enemy. Her life revolved around the intense fear of gaining weight and the overwhelming desire to be thin.

The young Canadian woman survived solely on coffee and skim milk for days at a time. At this time last year, she was malnourished, dehydrated and doctors told her she was several pounds away from death.

'I remember saying to myself a few times, 'I don't need food,' ' Yvonne said.

Between .5 and 1 percent of American women struggle with anorexia, and between 5 percent to 20 percent of individuals struggling with anorexia nervosa will die, according to the National Eating Disorders Association. Many have a story similar to Yvonne's.

Now, though, a cure may come in the form of a pill. Olanzapine, sold as Zyprexa in the United States, is currently used to treat schizophrenia and bipolar disorder. But eating disorder researchers are also finding that it can rid the mind of obsessive fear of weight gain.

Terrified of Eating, Terrified of Help

According to a Canadian research team, results of a recent pilot controlled study of 15 patients have been encouraging, though doctors admit more studies are still needed.

'It makes the patients less resistant and easier to work with,' said Dr. Wendy Spettigue of Children's Hospital of Eastern Ontario. 'That is very important when you have a patient that's coming in and terrified of eating and terrified of help and very angry and resistant.'

'We found people that, in taking this medication, the fear is decreased enough that they can enter treatment and some of them are all better now, whereas we thought many of them would never get better,' said Dr. Laird Birmingham of St. Paul's Hospital in Vancouver, British Columbia. 'So this is an amazing discovery.'

Now enrolled in a day therapy program for those with eating disorders, Yvonne is gaining weight and her progress is promising.

'It got rid of 99.9 percent of the anorexic thoughts,' Yvonne said. 'It got rid of all my obsessive thoughts about all the problems that I had that caused the anorexia in the first place. I'm actually eating, for the first time in two years, three meals a day.'

Not the Sole Treatment

Other doctors are reacting positively to the use of Zyprexa as a treatment for anorexia, though they say it isn't for all anorexic patients.

The drug has worked well for some anorexic patients on 'a relentless pursuit of thinness' said Dr. Mae Sokol of the Children's Hospital of Omaha in Nebraska. Before Zyprexa, neither she nor her colleagues had much success in getting patients to gain weight outside the hospital.

She said she would not use it for bulimics, and warned that the drug cannot be the sole treatment for anorexic patients. Doctors must remember that the patients have a mental disorder and need counseling.

'Anorexics are often 'good little girls starving themselves to death,'' Sokol said. 'They tend to be pretty, well-dressed, straight-A students with perfectionist personality traits. For this reason it is hard not to forget that they are psychotic nonetheless.'

Like depressed and schizophrenic patients, anorexics have thoughts that are out of touch with reality. Some say 'I'm as fat as a house' or 'I'm the biggest one in the room,' and they truly believe it, Sokol said.

Most of the obsessive thoughts are the body's physical reaction to malnutrition, she said.

'Some patients will eat either nothing all day or between 200 to 300 calories and believe that they are eating too much,' Sokol said. 'Medicine is only a useful addition to the rest of treatment, such as teaching a patient how to eat and new ways to think.'

Treatment is always individualized to the patient, she said.

Sokol said she will usually stop a patient's Zyprexa treatment in the month after a target weight is reached, in part because a patient's obsessive thoughts tend to decrease or normalize once she achieves a normal weight.

Side Effects Need Study

The drug is promising trend, but its side effects and effectiveness need more study, said Dr. Ovidio Bermudez, clinical director of adolescent medicine and behavioral science at the Eating Disorders Program in Nashville, Tenn. He said Zyprexa has helped some of the program's patients.

According to research, side effects include weight gain, which is actually beneficial given this condition, and other problems like dry mouth, constipation and some changes in liver function.

Doctors say they increase the dose gradually and that most of the side effects have been well tolerated. Younger patients tend to use the drug for a short duration, six months to a year.

Dr. Barton J. Blinder, a clinical professor of psychiatry at University of California at Irvine's College of Medicine, found that the drug, in graded doses, has helped some of the psychological behavior involved with anorexia nervosa, in that it decreases obsession behavior and encourages patients to eat.

'Our clinical experience has been positive - we often combine with small dose of mitarpizine,' Blinder said. Mitarpizine, an antidepressant, is marketed as Remeron.

One problem with this treatment is that when anorexic patients read pamphlets explaining the medication, they learn that weight gain is a possible side effect. Patients warn each other of the potential side effect, Sokol said. Some patients are hesitant to take it, and others refuse.