Eating Disorders Common Among Adolescents
Eating disorders were found to be common among the general U.S. adolescent population by Kathleen Merikangas, PhD, of the National Institute of Mental Health in Bethesda, Md, and colleagues whose finding were published online March 7, 2011 in the Archives of General Psychiatry.
Merikangas and colleagues found adolescents have eating disorders at rates only slightly lower than adults. Studies of adults suggest that the rates of anorexia nervosa and bulimia nervosa range from 0.5% to 1.0% and from 0.5% to 3.0%, respectively.
The researchers also found most adolescents with an eating disorder have at least one other psychiatric comorbidity, including suicidal thoughts.
Merikangas and colleagues examined eating disorders using data from the National Comorbidity Survey Replication Adolescent Supplement (NCS-A), a sample of U.S. adolescents which involved face-to-face interviews with a nationally-representative sample of 10,123 adolescents, ages 13 through 18.
The objectives of the study included 1) determining the lifetime and 12-month prevalences of anorexia nervosa (AN), bulimia nervosa (BN), binge-eating disorder (BED) and subthreshold eating disorders; 2) examining their sociodemographic and clinical correlates and patterns of comorbidity with other mental disorders; and 3) to describe the magnitude of role impairment, suicidal behavior, and service use associated with these disorders.
The researchers found that lifetime and 12-month prevalence rates of anorexia nervosa was 0.3% and 0.2% respectively. For bulimia the corresponding rates were 0.9% and 0.6%.
The lifetime and 12-month prevalence rates for binge eating were 1.6% and 0.9% respectively. For sub-threshold binge eating were 2.5% and 1.1%, respectively.
Regarding lifetime prevalence estimates, there were no sex differences in the prevalence of anorexia nervosa or subthreshold binge eating. The other eating disorders (bulimia, binge eating disorder, and subthreshold anorexia nervosa) were more prevalent in girls.
The researchers noted 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. This was highest among adolescents with bulimia (88%), followed by adolescents with binge eating disorder (83.5%), subthreshold anorexia nervosa (79.8%), subthreshold binge eating (70.1%), and anorexia nervosa (55.2%).
Merikangas and colleagues cautioned that the cross-section design of the study means that it is not possible to make conclusions about the temporal relationships of eating disorders and comorbid conditions.
Eating disorders were most strongly associated with social impairment. Nearly all of those with anorexia nervosa (88.9%) reported social impairment, and 19.6% reported severe social impairment associated with their eating disorder.
The researchers found lifetime suicidality was associated with all subtypes of eating disorders with 53% of those with bulimia reporting suicidal ideation.
The investigators found that only a minority of the teens had specifically sought treatment for their eating disorder, with rates ranging from 3.4% among those with sub-threshold binge eating to 27.5% for those with anorexia.
The researchers cautioned that, among other limitations, the small numbers of teens with an eating disorder found in this survey means that analyses of possible associations may have been under-powered.
Nonetheless, they concluded that the study "provides key information concerning the epidemiology of eating disorders" among U.S. teens and shows that they "represent a major public health concern."
Sonja A. Swanson; Scott J. Crow; Daniel Le Grange; Joel Swendsen; Kathleen R. Merikangas; Prevalence and Correlates of Eating Disorders in Adolescents: Results From the National Comorbidity Survey Replication Adolescent Supplement; Arch Gen Psychiatry. 2011;0(2011):archgenpsychiatry.2011.22.