Carlos Grilo, PhD, Professor of Psychiatry and of Psychology and Director of the Program for Obesity Weight and Eating Research (POWER) at Yale, is the senior author of a new study published in Biological Psychiatry that revises the outdated estimates of the prevalence of eating disorders in the United States.
According to a news release by Biological Psychiatry, the new estimates were based on a nationally-representative sample of 36,309 adults -- the largest national sample of U.S. adults ever studied. The findings estimate that 0.80 percent of U.S. adults will be affected by anorexia nervosa in their lifetime; 0.28 percent will be affected by bulimia nervosa; and 0.85 percent will be affected by binge eating disorder.
Importantly, the study provides the first prevalence estimates using the current definitions of eating disorders. Although the diagnostic criteria for several common eating disorders were changed with the 2013 publication of the "Diagnostic and Statistical Manual of Mental Disorders (DSM)-5," the rates of eating disorders hadn't been studied since 2007.
"Our study confirms that eating disorders are common, are found in both men and women and across ethnic/racial groups, occur throughout the lifespan, and are associated with impairments in psychosocial functioning," said first author Tomoko Udo, PhD, of University at Albany, New York. Udo conducted the study alongside Grilo.
"The prevalence and impact of eating disorders continues to be underestimated in society. This definitive study should guide both research and policy development," said John Krystal, MD, Chair of the Yale Department of Psychiatry and Editor of Biological Psychiatry.
The data analyzed in the study were from the 2012-2013 National Epidemiologic Survey Alcohol and Related Conditions (NESARC-III). In addition to lifetime estimates, the study found that 12-month estimates for anorexia nervosa, bulimia nervosa, and binge eating disorder were 0.05 percent, 0.14 percent, and 0.44 percent, respectively. The rates of anorexia nervosa were similar to previous estimates, but the researchers were surprised to find the rates of bulimia nervosa and binge eating disorder were lower than previous estimates.
"Many researchers and clinicians expected higher estimates than earlier studies as a result of 'loosening' of diagnostic criteria for eating disorders," said Udo, referring to the changes made to criteria in the DSM-5. She added that more large-scale epidemiological studies will be needed to explain the reason for these unexpected findings and to better understand the impact of changes in diagnostic criteria.
The disorders occurred across different ages and were persistent, lasting for years. The study also reported that the eating disorders included in analysis often interfere with normal daily activities and social relationships.
According to Udo, the findings show that eating disorders represent an important public health problem and demonstrate the importance of screening for eating disorders across all socio-demographic groups. "Binge eating disorder, a new 'formal' diagnosis in the DSM-5, is especially important to screen for and identify, as it is associated with substantially increased risk for obesity yet often goes unrecognized," she said.
"In many communities, specialty treatment for eating disorders is not as easily accessible as for other psychiatric and medical conditions, and thus improving access to care is an important priority for healthcare systems," Udo said.