By Psych Central News Editor Reviewed by John M. Grohol, Psy.D. on March 7, 2011

In any given year, nearly 1 in 60 teens would qualify for an eating disorder diagnosis such as anorexia, bulimia or binge eating disorder. More specifically, a new study from the National Institute of Mental Health found that the one-year prevalence rate of eating disorders in teens is 1.7 percent.

That figure is a more precise measure that is in line with previous estimates.

Sonja Swanson, Sc.M., of the National Institute of Mental Health, and colleagues examined eating disorders with data from the National Comorbidity Survey Replication Adolescent Supplement (NCS-A), a nationally representative sample of U.S. adolescents. the sample included face-to-face interviews with 10,123 adolescents ages 13 to 18 years.

Eating disorders are a group of mental health concerns that include anorexia, bulimia, binge eating disorder, and other types of disordered eating.

The objectives of the study included determining the lifetime and 12-month prevalences of anorexia nervosa (AN), bulimia nervosa (BN), binge-eating disorder (BED) and subthreshold eating disorders; examining their sociodemographic and clinical correlates and patterns of comorbidity with other mental disorders; and to describe the magnitude of role impairment, suicidal behavior, and service use associated with these disorders.

A subthreshold eating disorder is defined as a set of symptoms that do not meet existing eating disorder criteria. A person with such symptoms, however, may meet the criteria for an eating disorder criteria in the future.

The researchers felt as if they had sufficient information as to define subthreshold anorexia (SAN) and subthreshold bulimia (SBED) among those youths who did not meet criteria for AN, BN, or BED.

The researchers found that lifetime prevalence rates — that is, the likelihood of a person having it over the course of their lifetime — of AN, BN and BED were 0.3 percent, 0.9 percent and 1.6 percent, respectively.

The 12-month prevalence rates of anorexia, bulimia, and binge eating disorder were 0.2 percent, 0.6 percent and 0.9 percent respectively (equaling a 1.7 percentage rate for all three disorders together).

For subthreshold eating disorders, the lifetime prevalence rates were 0.8 percent for SAN and 2.5 percent for SBED, while the 12-month prevalence rates were 0.1.1 for SBED.

Regarding lifetime prevalence estimates, there were no sex differences in the prevalence of AN or SBED, whereas BN, BED, and SAN were more prevalent in girls.

Although the lifetime prevalence estimates of eating disorders from population-based studies of adults are relatively low, their severity and dramatic effects have been repeatedly demonstrated through elevated rates of impairment, medical complications, other illnesses, death and suicide, according to background information in the article.

The majority of respondents with an eating disorder met criteria for at least 1 other lifetime DSM-IV disorder (classification of mental disorders) assessed in this study across the lifetime, with 55.2 percent, 88.0 percent, 83.5 percent, 79.8 percent, and 70.1 percent of adolescents with AN, BN, BED, SAN, and SBED, respectively, endorsing 1 or more co-existing psychiatric disorders.

Among adolescents with 12-month AN, BN, BED, and SBED, 97.1 percent, 78.0 percent, 62.6 percent, and 34.6 percent, respectively, reported impairment in the past 12 months; 24.2 percent, 10.7 percent, 8.7 percent, and 2.8 percent, respectively, reported severe impairment. Eating disorders were most strongly associated with social impairment.

Nearly all of those with anorexia (88.9 percent) reported social impairment, and 19.6 percent reported severe social impairment associated with their eating disorder. Lifetime suicidality was associated with all subtypes of eating disorders.

Although the majority of adolescents with an eating disorder sought some form of treatment, only a minority received treatment specifically for their eating or weight problems.

According to the authors, “… this study provides key information concerning the epidemiology of eating disorders in the U.S. adolescent population. the prevalence of these disorders is higher than previously expected in this age range, and the patterns of comorbidity, role impairment, and suicidality indicate that eating disorders represent a major public health concern. Finally, these findings support the nosological distinction [classification of diseases] between the major subtypes of eating disorders as well as the importance of inclusion of the full spectrum of eating behaviors in estimating the magnitude and correlates of eating disorders in the U.S. population.”

The study was published in the March 7 issue of the Archives of General Psychiatry.

Source: Archives of General Psychiatry. doi:10.1001/archgenpsychiatry.2011.22.