Examining the significance of age of onset in persons with lifetime anorexia nervosa: Comparing child, adolescent, and emerging adult onsets in nationally representative U.S. study.

OBJECTIVE: This study compared sociodemographic and clinical profiles of adult patients with lifetime DSM-5-defined anorexia nervosa (AN) categorized by age-of-onset using data from U.S. national sample of adults.
METHOD: Study included 216 participants from Third National Epidemiological Survey Alcohol and Related Conditions (NESARC-III) who met criteria for lifetime AN based on structured diagnostic interviews (AUDADIS-5) with age-of-onset prior to age 25. Of the 216 participants, 30 were categorized as child-onset (<15 years old), 104 adolescent-onset (15-18 years of age), and 82 "emerging-adult" (19-24 years of age); the three groups were compared on their clinical characteristics.
RESULTS: Among participants with lifetime diagnoses of AN with onsets earlier than 25 years, adjusted prevalence rates for the three groups were: 11.8% (SE = 2.04; child-onset), 39.6% (SE = 2.69; adolescent-onset), and 48.6% (SE = 2.67; emerging-adult). Child-onset group reported more frequent adverse childhood experiences (ACEs), lowest BMI, longest episode-duration, was least likely to attend college, and had highest rate of lifetime psychiatric comorbidity. Child-onset group had earliest age of help-seeking and were most likely to have been hospitalized. Group differences persisted in analyses adjusting for sociodemographic characteristics and duration of AN episode. DISCUSSION: Our findings, based on a nationally representative sample of U.S. adults with lifetime diagnoses of AN, suggest that those with child-onset had more severe AN, greater life difficulties, and greater lifetime psychiatric comorbidity. Findings emphasize the importance of earlier recognition and rapid referral to effective treatments.