National population-based data on the incidence, prevalence, and psychiatric comorbidity of eating disorders in Taiwanese adolescents and young adults

Objective: Nationwide data on eating disorders (EDs) among East Asian populations are scarce. This study aimed to estimate the prevalence, incidence, and psychiatric comorbidities of EDs in Taiwan. Method: Drawing from the National Health Research Institute database, we identified the study subjects aged 11–34 years who received an ED diagnosis during ambulatory visits or hospitalization from 2001 to 2012. We analyzed the subjects by age and gender. Diagnoses for comorbid psychiatric disorders were entered in the analysis only if they occurred within 1 year before or after the ED diagnosis date. Rates were age- and sex-adjusted to the average population within the study period. Results: The estimated mean annual incidence was approximately 11.11 (95% CI 10.51–11.72) per 100,000 residents, and the 1 year prevalence was 20.87 (95% CI 20.05–21.70) per 100,000 residents, with evidence of female predominance (female/male ratio = 10.95, 95% CI = 8.97–13.36). Incidence and prevalence peaked at ages 20–24 in females and at ages 25–29 in males. Both rates nearly doubled within a decade. Specifically, the anorexia nervosa trend recently stabilized in females and decreased in males, while that for bulimia nervosa increased in both females and males. The most common comorbid diagnoses were anxiety (53%) and major depressive disorders (22%). Discussion: The incidence and prevalence of EDs were lower in Taiwan than in Western countries. However, these rates were rapidly rising, notably in males. The majority of Taiwanese ED patients also received a diagnosis for various psychiatric comorbidities, a finding worthy of clinical attention.