Epidemiology of anorexia nervosa in Japanese adolescents

Abstract

BackgroundNo epidemiologic survey examining eating disorders in Japan has been done at a national level since 1992. The prevalence of anorexia nervosa, as assessed by questionnaires to hospitals, is thought to be underestimated because patients with anorexia nervosa tend to avoid consultations. In conformity with the School Health and Safety Act of Japan, schools are required to have physicians perform a medical examination of students every year. The teachers in charge of health education and school physicians determine the height, weight, and health condition, and examine the medical records of each student. Therefore, we as members of the Survey Committee for Eating Disorders of the Japanese Ministry of Health, Labour, and Welfare conducted an epidemiologic survey using questionnaires sent to schools in seven prefectures to determine the current prevalence of anorexia nervosa among adolescents.MethodsWe sent a questionnaire to elementary, junior high, and senior high schools. Questionnaires contained items on the number of students, patients with anorexia nervosa in each grade who were diagnosed by specialists, and students who the school physician strongly suspected to have anorexia nervosa but who did not undergo a clinical examination in a medical institution.ResultsWe found patients of both sexes with anorexia nervosa aged 9–10 years in elementary schools. The point prevalence of anorexia nervosa for girls, including strongly suspected cases, in the three grades of junior high school and three grades of senior high school were 0–0.17 %, 0–0.21 %, 0.17-0.40 %, 0.05-0.56 %, 0.17-0.42 % and 0.09-0.43 %, respectively. We also confirmed a prominent sex difference in the prevalence of anorexia nervosa. The prevalence of boys was one third that of girls in some prefectures. One third to one half of diagnosed and strongly suspected students with anorexia nervosa had not received medical consultation or treatment.ConclusionsAlthough the prevalence of anorexia nervosa had regional differences in Japan, it has reached levels comparable to those in Western societies. Because no eating disorder center exists and the treatment environment is poor, national action to address this disease is a pressing need in Japan.

Transitioning from DSM‐IV to DSM‐5: A systematic review of eating disorder prevalence assessment

“…The most commonly used interview was the SCID (all SCID interview formats included), 12,99,100 applied in 9 (31.0%) out of 29 studies, closely followed by the EDE. Sample sized ranged from 93 92 to 252 838, 77 with the vast majority of studies (39 studies) presenting prevalence data on samples ranging in size from 1000 to 5000 participants. For the proportion of studies assessing ED prevalence using interviews only, nearly 50% (10 out of 22) of studies reported having used the WHO WMH-CIDI, 11 or modified versions of this instrument.…”

“…13 Thirteen (24.5%) studies reported interviewing participants using [clinical] interviews based on DSM-IV criteria, without specifying details. The remaining 3 studies reported sample sizes ranging from between 30 000 to over 250,000 participants, the 2 two largest using either self-report (N 5 252,838), 77 or interview (N 5 100,000) 59 to assess ED prevalence. Eight of these 10 studies were American.…”

Past, Current and Future of Anorexia Nervosa in Japan

“…Only one study used interviews of 1,130 females by nursing teachers among 13 high schools in Japan, and the highest prevalence was reported (2.03% in 2002) [24]. The most recent survey has been published by Hotta et al [25] using a questionnaire to elementary, junior high, and senior high schools in seven prefectures. The point prevalence of AN for girls, including strongly suspected cases, in the three grades of junior high school and three grades of senior high school were 0-0.…”

Childhood dietary intake: Comparison between anorexia nervosa and healthy leanness

“…Furthermore, the symptoms of AN in childhood are atypical, therefore this condition is often overlooked, and patients eventually visit the hospital only after it has become advanced. According to epidemiological research conducted in junior high and high schools, one‐third–one‐half of AN patients had not visited a doctor and had not received treatment …”

“…According to epidemiological research conducted in junior high and high schools, one-thirdone-half of AN patients had not visited a doctor and had not received treatment. 15 To achieve early detection of difficult-to-find AN in children and adolescents, it is therefore important not to miss the initial signs. The first sign of AN is abnormal eating behavior based on fear of becoming fat, leading to a significant decrease in energy intake.…”