The definition of anorexia nervosa was revised for the Fifth Edition of the Diagnostic and Statistical Manual (DSM-5). We examined the impact of these changes on the prevalence and prognosis of anorexia nervosa. In a nationwide longitudinal study of Finnish twins born 1975-1979, the women (N = 2825) underwent a 2-stage screening for eating disorders at mean age 24. Fifty-five women fulfilled DSM-IV criteria for lifetime anorexia nervosa. When we recoded the interviews using DSM-5 criteria, we detected 37 new cases. We contrasted new DSM-5 vs. DSM-IV cases to assess their clinical characteristics and prognosis. We also estimated lifetime prevalences and incidences and tested the association of minimum BMI with prognosis. We observed a 60% increase in the lifetime prevalence of anorexia nervosa using the new diagnostic boundaries, from 2.2% to 3.6%. The new cases had a later age of onset (18.8 y vs. 16.5, p = 0.002), higher minimum BMI (16.9 vs. 15.5 kg/m(2), p = 0.0004), a shorter duration of illness (one year vs. three years, p = 0.002), and a higher 5-year probability or recovery (81% vs. 67%, p = 0.002). Minimum BMI was not associated with prognosis. It therefore appears that the substantial increase in prevalence of anorexia nervosa is offset by a more benign course of illness in new cases. Increased diagnostic heterogeneity underscores the need for reliable indicators of disease severity. Our findings indicate that BMI may not be an ideal severity marker, but should be complemented by prognostically informative criteria. Future studies should focus on identifying such factors in prospective settings.

Objective: We aimed to assess the lifetime prevalence, 10-year incidence, and peak periods of onset for eating disorders as defined by the Fifth Diagnostic and Statistical Manual of Mental Disorders (DSM-5) among adolescents and young adults born in the 1980s in Finland.Method: Virtually all Finnish twins born in 1983-1987 (n = 5,600) were followed prospectively from the age of 12 years. A subsample of participants (n = 1,347) was interviewed using a semi-structured diagnostic interview in their early twenties.Results: The prevalence of lifetime DSM-5 eating disorders was 17.9% for females and 2.4% for males (pooled across genders, 10.5%). The estimated lifetime prevalences for females and males, respectively, were 6.2 and 0.3% for anorexia nervosa (AN), 2.4 and 0.16% for bulimia nervosa (BN), 0.6 and 0.3% for binge-eating disorder (BED), 4.5 and 0.16% for other specified feeding or eating disorder (OSFED), and 4.5 and 1.6% for unspecified feeding or eating disorder (UFED). Among females, the prevalence of OSFED subcategories was as follows: atypical AN 2.1%, purging disorder 1.3%, BED of low frequency/limited duration 0.7%, and BN of low frequency/ limited duration 0.4%. The 10-year incidence rate of eating disorders was 1,700 per 100,000 person-years among females (peak age of onset 16-19 years) and 220 per 100,000 person-years among males.Discussion: Eating disorders are a common public health concern among youth and young adults, affecting one in six females and one in 40 males. Adequate screening efforts, prevention, and interventions are urgently needed.

Purpose of reviewEating disorders (anorexia nervosa, bulimia nervosa, binge eating disorder, and other eating disorders) affect young people worldwide. This narrative review summarizes key studies conducted on the prevalence of Diagnostic and Statistical Manual of Mental Disorders (DSM-5) eating disorders among young people in 2013-22.Recent findingsIn Western settings, a substantial proportion of young people have reported an eating disorder. Overall, 5.5--17.9% of young women and 0.6–2.4% of young men have experienced a DSM-5 eating disorder by early adulthood. Lifetime DSM-5 anorexia nervosa was reported by 0.8–6.3% of women and 0.1–0.3% of men, bulimia nervosa by 0.8–2.6% of women and 0.1–0.2% of men, binge eating disorder by 0.6–6.1% of women and 0.3–0.7% of men, other specified feeding or eating disorders by 0.6–11.5% of women and 0.2–0.3% of men, and unspecified feeding or eating disorders 0.2–4.7% of women and 0–1.6% of men. Gender and sexual minorities were at particularly high risk. Emerging studies from Eastern Europe, Asia, and Latin America show similar high prevalences. During the COVID-19 pandemic, the incidence of eating disorders has still increased.SummaryEating disorders are a global health concern among young people. Improved detection, management, and prevention methods are urgently needed.

Objective: We assessed the detection, treatment and outcomes of DSM-5 eating disorders in a nationwide community setting. Method:The FinnTwin12 cohort comprises twins born in 1983 -1987, with follow-up starting at age 12. We outline treatment and outcomes of the 127 females and 15 males diagnosed with a lifetime DSM-5 eating disorder in interviews conducted for a subsample (n = 1,347) in their early 20s.Results: Only 45 (32%) of those diagnosed with eating disorder in the interviews had their condition detected in healthcare, and even fewer received treatment (30% of females, 13% of males). Anorexia nervosa (AN), bulimia nervosa, and atypical AN were detected and treated more often than other eating disorders. Five years after disease onset, 41% of those diagnosed had recovered. There were no statistically significant differences in the course of different eating disorders (log-rank p = 0.66) but the outcome was more favourable among males (log-rank p = 0.008). The likelihood of 5-year recovery did not differ between those who had and who had not received treatment (41.1% vs. 40.5%, log-rank p = 0.66). Conclusion:Although eating disorders are common and symptoms are persistent for many, they remain under-diagnosed and under-treated. In realworld settings, effectiveness of provided treatments may be limited.Abbreviations: AN, anorexia nervosa; Atypical AN, atypical anorexia nervosa; BED, binge eating disorder; BN, bulimia nervosa; CI, confidence interval; DSM-5, Diagnostic and Statistical Manual of Mental Disorders fifth edition; ED, eating disorder; EDNOS, eating disorder not otherwise specified; Mm-MAST, the Malmö-modified Michigan Alcoholism Screening Test; OSFED-BED, binge eating disorder of low frequency and/or limited duration; OSFED, other specified feeding or eating disorder; OSFED-BN, bulimia nervosa of low frequency and/or limited duration; PD, purging disorder; SCID, the Structured Clinical Interview for DSM-IV; SD, standard deviation; UFED, unspecified feeding or eating disorder.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.