Binge eating disorder (BED) is the most prevalent eating disorder among Americans, affecting an estimated 1% to 3% of individuals. The disorder is characterized by loss of control over eating. The amount eaten in a binge-eating episode can vary widely among those affected. While often it is more than most people would consume under similar circumstances, the key factor in diagnosis concerns loss of control.

The 4th edition of the DSM diagnostic manual used by psychiatrists and other medical professionals established that a diagnosis could be made with binge-eating episodes on two or more days per week over a 6-month period. The revised 5th edition requires 1 episode or more per week over 3 months to make a positive diagnosis. The key in both definitions is loss of control when eating, regularly, over a period of months.

A number of basic questions are as yet unanswered regarding this prevalent disorder, some of which are addressed in a newly published study. Although it was once assumed by some experts that those most often affected are young and female, it has become clear that males also develop BED. Health statistics suggest that the average age of onset is 25, although studies have yielded conflicting results regarding what doctors call “the natural course” of the disorder, i.e., when it typically begins, how long it lasts, what portion of patients achieve remission, how long it takes to achieve remission, and how long remission, when experienced, typically endures until there is a relapse.

To answer some of these questions, a team led by 2023 BBRF Young Investigator Kristin N. Javaras, D.Phil., Ph.D., of McLean Hospital and Harvard Medical School, used data collected by Drs. James Hudson and Harrison Pope, Jr., and colleagues, who followed, over a period of years, a subset of individuals from the community who were enrolled in a study examining BED and who entered that study with a current BED diagnosis. The goal of Dr. Javaras’ new study was to characterize remission and relapse from BED in individuals from the community, and to identify specific demographic or clinical features that make remission more or less likely. “Little is known about the demographic and clinical predictors of the natural course of BED,” the team noted in a paper in Psychological Medicine reporting their results. Cynthia M. Bulik, Ph.D., 2017 BBRF Distinguished Investigator, was also a member of the team.

The researchers examined the cases of 137 individuals, assessing them in various ways at baseline and after 2.5 and 5 years following their enrollment in the study. The researchers looked for changes in BED diagnostic status over the follow-up period, meaning whether or not they continued, at each follow-up, to meet criteria for BED, or one of 4 “sub-threshold” definitions of BED in which some symptoms were present but did not qualify for a “full” diagnosis, or had no BED symptoms, i.e., were in remission.

The study was intended to be representative of typical BED patients: it was larger than past longitudinal studies; included only subjects from “the community,” i.e., people who were not part of a treatment study and may or may not have been in treatment; included male subjects; and included only adults with a comparatively high body-mass index (BMI) score. These criteria were established in the hope of clarifying conflicting results in past studies.

While several past retrospective studies, which rely on participants’ sometimes imperfect memories, have reported that BED lasts 7 to 16 years on average, a number of prospective studies that track people with the disorder over time have suggested that a significant portion of patients experience a remission within a year or two. These studies have been difficult to compare.

Results of the new study included a measure of good news: at the 2.5-year follow-up, BED status had improved for many participants from the full-BED diagnosis at the start of the study, and improved between that point and the 5-year follow-up. However: 61% of participants still met full criteria for BED at the 2.5-year point, and 45% at the 5-year point. These are based on the criteria for full BED diagnosis in the DSM-IV manual, which were used when the study began enrolling patients. If the DSM-V criteria were used, the percentages of participants still meeting full diagnosis at 2.5 years would have risen to 68% and at 5 years to 59%.

Only a small percentage of participants assessed after 2.5 years and 5 years were experiencing remission at those time points (15% and 22%, respectively.) Typical time to remission for those who achieved one was more than 5 years. For those who experienced remission, the typical time until a relapse was 30 months. “Relapse” in this context includes experiencing symptoms of “full-threshold” or “sub-threshold” BED—where sub-threshold BED refers to having binge-eating episodes fewer times per day, week, or month than full diagnosis requires, or what are called “mini-binges,” which usually involve smaller quantities of food but some degree of loss of control.

“Taken together,” the team summed up, “the majority of people with BED will experience some improvement in binge eating within a 5-year period, but achieving full remission within this time frame is not common.” Specifically, this refers to adults with BED with comparatively high body-mass index (BMI) scores.

The team stressed that the findings applied to a sample of people one would find in the population. This is important because most people with BED never become “patients”: a considerable majority either never seek treatment or cannot access it.

The good news is that talk therapy, including cognitive behavioral therapy (CBT) and interpersonal psychotherapy (IPT), are often effective in helping BED patients regain control over their eating. Lisdexamfetamine, a central nervous system stimulant, is the only drug to have been approved for use in BED, and has been shown in clinical trials to enable up to one-third of patients to achieve remission. When comparing the community sample in the current study to samples used in treatment studies (talk therapies or drugs), treatment appeared to lead to faster remission, suggesting the potential for benefit, provided treatment can be brought to more patients.

An open question about both talk therapy and drug treatment is how long their beneficial effects, when experienced, endure in typical patients, and which patients are most likely to be helped. These are among the questions to be addressed in future studies. Dr. Javaras and colleagues are now using neuroimaging technologies to get a better understanding of the biology involved in BED, which they hope will help in the effort to enhance current treatments and develop new ones. “We are also examining ways to catch people earlier, because many people don’t realize they have binge-eating disorder,” Dr. Javaras said.