Revamping our definitions of eating disorders

Psychologists are playing a major role in work to revise the eating-disorders criteria in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, due out in 2012. The manual's last substantive revision was in 2004.

Psychologists are lending their expertise in two ways. Four belong to the 11-member DSM Eating Disorders Work Group, one of 13 groups examining the book's diagnostic categories. In addition, four psychologists are working on an eight-member group that is conducting cutting-edge research and sharing it with the Eating Disorders Work Group to help it make more research-based recommendations. The research effort is made possible by an "R13" grant from the National Institute of Mental Health, a type of grant that supports scientific meetings.

"The effort is very important because it infuses data much more directly into the discussions about the next set of eating disorder diagnoses," says the effort's principal investigator, Stephen Wonderlich, PhD, Chester Fritz Distinguished Professor at the University of North Dakota School of Medicine and Health Sciences, who is also a member of the work group. "In addition to reviews of the literature and committee discussions, we are having scientists test ideas that are directly relevant to our decision-making."

The two groups are considering a number of diagnostic issues, many related to the question of whether to create new eating-disorder diagnoses or to allow more flexibility in the current diagnostic criteria, says the work group chair, Columbia University's B. Timothy Walsh, MD, who is also in the research group. One example is criteria for anorexia nervosa: Many clinicians report that some girls and women with symptoms of anorexia do not lose their periods, yet the current DSM requires amenorrhea as a condition of diagnosis, he explains. This criterion is also irrelevant to men and difficult to apply to women on birth control pills, Walsh notes.

The work group is also exploring the overarching diagnosis of Eating Disorders Not Otherwise Specified, says Wonderlich. Researchers estimate that 60 percent to 65 percent of eating-disorder diagnoses wind up in this category, including the atypical form of anorexia, he says.

"When the default diagnostic category is your primary category, that's a problem," he says.

The groups are also looking at whether to make binge-eating disorder an official diagnosis. It is currently in the DSM appendix and officially belongs in the broad Eating Disorders Not Otherwise Specified category. The researchers hope to determine whether people with the diagnosis differ over time in clinically important ways compared with other groups, such as those who are overweight or obese but don't meet the binge-eating criteria, Wonderlich says.

"These types of comparisons help us to assess the clinical utility of the diagnosis, which is a clinician's primary concern," he says. "The R13 group is searching for data that will further examine this issue."

The research group is also exploring how to classify eating disorders in children, how to include the cultural impact on eating disorders and how to define "binge," Wonderlich says.

The work group's next step is to complete a literature review, which it plans to wrap up by summer, Walsh says. The findings will be published and will offer a range of options for change that the field can comment on. After taking that input into account and doing further work, the work group will make formal recommendations to the DSM Task Force, which is charged with making the final revisions.

Walsh hopes the rigorous process will be heartening to clinicians comfortable with the current manual, he says.

"With all of the problems of current categories, people have gotten used to them and find them clinically useful," he says. "Any change will be disruptive, so we want to be as sure as possible that the changes will result in a more useful DSM."

Tori DeAngelis is a writer in Syracuse, N.Y.