Eating disorders (EDs) are associated with significant morbidity and mortality.1 The prevalence of early-onset EDs has increased in the past several decades, with younger children more likely than adolescents to experience psychiatric comorbidity. The single nationally representative study that has reported 12-month prevalence rates of EDs among children aged 8 to 15 years found 0.1% total for children aged 8 to 11 years, with 0.3% for girls and 0.1% for boys aged 8 to 15 years old.2 However, this previous study used Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria and did not report the prevalence of specific ED diagnoses. The aims of the present study were to report the prevalence rates of anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), and other specified feeding and eating disorders (OSFED) in addition to a global “any ED” diagnosis, using Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5) criteria among a US representative sample of children aged 9 and 10 years. Prevalence rates were tested by participant sex.
The present study used baseline data collected in 2016 and 2017 from the Adolescent Brain Cognitive Development (ABCD) study.3 Participants were a US representative sample of 4524 children aged 9 to 10 years and 1 of their caregivers. Participants in the ABCD cohort will be followed up for 10 years, with annual on-site assessments. Eating disorder diagnoses were determined using parent or guardian responses to the computerized Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) based on DSM-5 criteria.4 The KSADS categorized ED diagnoses into 5 clinical subtypes: AN, BN, BED, other specified feeding or eating disorders of the BN type (OSFED BN type) and OSFED BED type. In addition, global “any ED” and “any OSFED” variables were created. The San Diego State University institutional review board waived approval for our analyses. Parents and guardians provided written informed consent as part of the ABCD study. Statistical analysis was performed using SPSS Software (IBM). Poststratification sociodemographic weights were included in analyses to mirror the 2010 US Census. Results are therefore presented based on population-level estimates. Significant sex differences in ED diagnoses was determined by the adjusted F, a variant of the second-order Rao-Scott adjusted χ2 statistic.5
Among the total population of 8 080 738 participants, 51.5% were boys, 76.0% were white, and 24.0% were Hispanic. Across all ED diagnoses, boys and girls did not have statistically significant differences in prevalence rates (Table). Across all ED diagnoses, the overall prevalence rate was 1.4% (95% CI, 1.0%-1.8%). The prevalence of any OSFED diagnosis was 0.7% (95% CI, 0.5%-1.0%). The prevalence of AN was 0.1% (95% CI, 0.0%-0.3%). No cases of BN were present in this sample. Finally, the prevalence of BED was 0.6% (95% CI, 0.4%-0.9%).
Significant sex differences were not found across ED diagnoses. Similarly, past research with adolescents aged 13 to 18 years did not find sex differences in the prevalence of AN; however, differences emerged for BN, BED, and subthreshold AN, with higher prevalence among girls.6 Taken together, sex differences in EDs may not emerge until adolescence. This is consistent with previous research demonstrating a lack of prepubertal sex differences in EDs, with elevated prevalence of EDs in girls during and after puberty.7 Limitations of the study include the exclusion of OSFED AN, which the KSADS operationally defined only by caregivers’ report of emaciation, and no assessment of avoidant and restrictive food intake disorder. Although EDs are not the focus of the ABCD study, use of the KSADS as opposed to a diagnostic tool tailored to EDs is also a limitation. The low prevalence of EDs may have reduced statistical power to detect sex differences. Future researchers may wish to characterize this sample in greater detail, including assessment of race/ethnicity, body mass index, and psychiatric comorbidity. As the ABCD cohort releases additional waves of data, researchers are encouraged to harness this nationally representative, prospective data set to explore developmental risk factors for EDs.
Corresponding Author: Aaron J. Blashill, PhD, Department of Psychology, San Diego State University, 6363 Alvarado Ct, Ste 101, San Diego, CA 92120 (ajblashill@sdsu.edu).
Accepted for Publication: August 6, 2018.
Published Online: November 26, 2018. doi:10.1001/jamapediatrics.2018.3678
Author Contributions: Ms Rozzell and Dr Blashill had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Concept and design: Rozzell, Brown, Blashill.
Acquisition, analysis, or interpretation of data: Moon, Klimek, Blashill.
Drafting of the manuscript: Rozzell, Moon, Klimek, Blashill.
Critical revision of the manuscript for important intellectual content: Rozzell, Klimek, Brown, Blashill.
Statistical analysis: Blashill.
Administrative, technical, or material support: All authors.
Supervision: Klimek, Blashill.
Conflict of Interest Disclosures: None reported.
Disclaimer: This article reflects the views of the authors and may not reflect the opinions or views of the National Institutes of Health (NIH) or the Adolescent Brain Cognitive Development (ABCD) Study consortium investigators.
Additional Information: Data used in the preparation of this article were obtained from the ABCD Study, held in the National Institutes of Mental Health Data Archive. The ABCD Study is supported by awards U01DA041022, U01DA041028, U01DA041048, U01DA041089, U01DA041106, U01DA041117, U01DA041120, U01DA041134, U01DA041148, U01DA041156, U01DA041174, U24DA041123, and U24DA041147 from the NIH and other federal partners. A full list of supporters is available at https://abcdstudy.org/federal-partners.html. The ABCD data used in this report came from 10.15154/1412097.