Michelle Cruz was 14 years old when she read a story in a teen magazine about girls vomiting to lose weight.
"I took it the wrong way," she said. "I don't think it was meant as a how-to, but it gave me the idea. I tried it right away. I lost weight, my body felt better, I thought I was faster, quicker and better at sports."
It wasn't until she collapsed at age 15 while playing high school volleyball that it was revealed she had an eating disorder. She was hospitalized for anorexia nervosa and treated with the antidepressant Prozac.
While she says the drug helped her recover, medical research is less clear about its benefits for people with eating disorders. Specifically, a new study now shows that Prozac, also known as fluoxetine, may not be the magic bullet doctors and patients hoped it would be, although it does appear to help some women, like Cruz.
In a study published in the Journal of the American Medical Association, researchers compared Prozac to a placebo to try to prevent relapse of anorexia nervosa in women who had successfully regained weight.
"The results were disappointing, and surprising," said Dr. Timothy Walsh, the study's lead researcher and a professor of psychiatry at the New York State Psychiatric Institute at Columbia University Medical Center. "Fluoxetine was no better than the placebo in preventing illness."
Less than one third of the women were able to maintain the weight they'd regained (27 percent of the fluoxetine group and 32 percent of the placebo group). Experts had hoped a combination of psychotherapy and medication would lead to treatment success.
A Challenging Illness to Treat
Since many anorexics also suffer from depression and anxiety, there has been keen interest in antidepressants, and many patients are currently treated with them. Many case studies have been positive, such as Cruz's story.
"I was on Prozac for a long time and felt good," she said. "I stopped taking it on my own when I went to college. I got worse after stopping and felt worse when I wasn't on something."
After two hospitalizations and several different antidepressants, Cruz is now 34, married and a mother of two. She hasn't relapsed in 14 years and continues to take an antidepressant daily but hopes she'll be able to stop someday.
While her treatment has been a success, treating eating disorders challenges many doctors.
"A big part of this illness is denial," Walsh said. "The illness itself interferes with its own treatment. Once it's established, it becomes a habit with strong staying power."
Often when patients start to regain weight old habits kick in, and they abandon treatment. Walsh said this is why it's difficult to study anorexia nervosa -- it's hard to keep patients actively engaged in studies designed to help them keep their weight up.
May Help Some Sufferers
And while he and the other study authors state they believe this is "the largest controlled medication trial conducted to date on anorexia nervosa," more than half the women dropped out before the end of the study.
The study included 93 women in New York and Toronto between the ages of 16 and 45, who had regained weight as a result of being treated for their anorexia nervosa.
The goal was to see if over the course of one year fluoxetine could prevent them from relapsing and losing the weight. In addition to receiving either the study medication or the placebo, all study participants also received a form of psychotherapy -- cognitive behavioral therapy.
While the results were disappointing, Prozac may not be entirely useless for treating eating disorders.
"Studies always look at groups of patients, not individuals, to determine if on average there will be benefit to patients," he said, explaining that some patients may benefit from taking it, although, on average, Prozac was no better than the placebo for preventing anorexia nervosa.
And, regardless, antidepressant therapy is not meant to be used alone, said Dr. Mae Sokol, a pediatrician and psychiatrist at Creighton University and medical director of the eating disorders program at Children's Hospital in Omaha.
"Medicine is only an adjunct to the rest of treatment, including dietary management and psychotherapy. Hopefully, patients will discuss this [study] with their doctors and make decisions on an individual basis," she said.
Walsh agreed, saying "studies need to be interpreted by patients and their physicians on a case-by-case basis. There's a clinical rule that says if a patient is doing well, change nothing."
As for his patients, he said, "I would not add a medication [to their current therapy] because there is no evidence it works."