Epidemiological data on anorexia nervosa in Japan

PSYCHIATRY RESEARCH Psychiatry Research 62 (1996) II- 16

ELSEVIER

Epidemiological

data on anorexia nervosa in Japan

Tomifusa Kuboki*“, Shinobu Nomura”, Masahiro Idea, Hiroyuki Suematsua, Shukuro Arakib “Depurtment

OfPsychosomatic Medicine, Branch Hospital, Faculty of Medicine. University of Tokyo, 3-28-6 Mejirodai, Bunk.vo-ku, Tok.vo 112. Japun

“Neurological Center, Department of Neurology, Mitsui Ohmuta Hospotal, Ohmuta. Fukuoka 836. Japan

Abstract An epidemiological survey on anorexia nervosa was performed in Japanese hospitals in 1985 and 1992 using a questionnaire. The reported number of patients with anorexia nervosa was 2391 from 732 institutions. From these data, the total number of anorexia nervosa patients treated in 1985 in Japanese hospitals was estimated to be about 3500-4500. In 1992, the reported number of patients with AN was 2247. The total number of AN patients treated in 1992 was estimated to be about 4500-4600, which is a little higher than that in 1985 (3.500-4500). The prevalence was 3.6-4.5 per 100000 among the general population, 6.3-9.7 per 10’ among the female population, and 25.2-30.7 per lo5 among the 13-29 year-old female population. Keywords:

Eating disorder; Cross-cultural;

Bulimia

1. Introduction Anorexia nervosa (AN) and bulimia nervosa (BN) are complex disorders that have become common in the past 20 years. AN is characterized by an all-consuming pursuit of thinness which overrides the physical and psychological wellbeing of the patient. Bruch (1970) reported that AN patients began to diet ostensibly to alter their weight, but this desire was often a screen which masked a pervasive sense of helplessness. AN is characterized by a consuming pursuit of thinness and BN is characterized by episodes of binge-purge eating. Garfinkel (1980) reported that AN occurred in *Corresponding author.

about 1% of young women, BN occurred in 223% of women, and milder variants of these disorders occurred in about 5% in America. About 95% of cases are female. These eating disorders remain a serious problem, causing significant mortality of about 5% and morbidity of about 25% of patients. Supported by the Japanese Ministry of Health and Welfare, we organized a research group on eating disorders. This group has been further divided into 5 sections, namely, epidemiological, etiological, psychopathological, pathophysiological and treatment sections. Table 1 shows our new diagnostic criteria which were revised in 1990 in accordance with DSM-111-R (American Psychiatric Association, 1987). Except for a body weight loss of 20%

0165!781/96/$15.00 $; 1996 Elsevier Ireland Ltd. All rights reserved SSDI Ol65-1781(96)02988-5

T. Kuhoki et al. I Psychiatry

12

instead of the 15% of DSM-III-R, our new criteria are similar to those of DSM-III-R. We added a remarks column to provide for a detailed description of these criteria. Epidemiological investigations were done in order to study the prevalence of anorexia nervosa in Japanese hospitals in 1985 and 1992. 2. Subjects and methods The subjects and methods of the 1985 study were as follows. A questionnaire, asking about the number of anorexia nervosa patients treated in 1985, was sent to physicians at 5283 institutions throughout Japan. There institutions included the departments of internal medicine, psychiatry, gynecology, psychosomatic medicine, and pediatrics at all medical colleges and university hospitals, and general and psychiatric hospitals having more than 200 beds. 3. Results Data were collected from 3397 (64.3%) of the 5283 institutions surveyed. In 2665 institutions, no anorexia nervosa patients were reported. In the remaining 732 institutions, 2391 patients with anorexia nervosa were reported (Table 3). From these data, the total number of anorexia nervosa patients treated in 1985 in Japanese hospitals was estimated to be about 3500-4500. The prevalence was 2.993.7 per 100000 among the general population, 5.1-8.0 per lo5 among the female population, and 20.4425.3 per lo5 among the 13-29-year-old female population. In 1992, an epidemiological investigation simi-

Table 1 Diagnostic

criteria

for anorexia

nervosa

in Japan

I. A weight loss of 20% or more of the standard body 2. Eating disorders (anorexia, bulimia, furtive eating, 3. A distorted cognition of body weight or shape (an fear of gaining weight) 4. Age at onset below 30 years of age 5. In females, amenorrhea 6. No known physical illness that would account for loss

Research

62 (1996)

lar to that of 1985 was carried out. Questionnaires were mailed to 5057 institutions. These institutions were mostly those surveyed in the 1985 study; however, only general and psychiatric hospitals having more than 300 beds, instead of the 1985 minimum of 200 beds, were included (Table 3). Data were collected from 1892 (37.4%) of the 5057 institutions surveyed. The reported number of patients with anorexia nervosa was 2247. The total number of anorexia nervosa patients treated in 1992 was estimated to be about 4500-5600, which is a little more than in 1985 (3500-4500). The prevalence was 3.6-4.5 per 100000 among the general population, 6.3-9.7 per lo5 among the female population and 25.2230.7 per lo5 among the 13-29-year-old female population. In the 1992 investigation, the number of bulimia nervosa patients was reported as 1196. The estimated total number of bulimia nervosa patients treated was 1600-3000. Prevalence of bulimia nervosa was 1.3-2.5 per lo5 among the general population, 3.2-4.3 per lo5 among the female population, and 12.8-13.6 per lo5 among the 13-29-year-old female population (Table 4). 4. Discussion Because anorexia nervosa patients often deny the existence of the disease, and because they tend not to seek hospital treatment, investigations centered on schools are being carried out around the country by members of our research team. We did a survey looking at the desire to lose weight among 1794 Tokyo high school girls. As shown in Fig. 1, depending on the weight group,

Table 2 Surveyed weight etc.) intense

weight

I l-16

institutions

Medical colleges and university hospital departments Internal medicine Psychiatry Gynecology Pediatrics General hospitals having more than 200 beds Psychiatric hospitals

T. Kuhoki et al. I Psychiatry

Table 3 Epidemiological study on anorexia nervosa (AN) in Japan

Number of surveyed institutions Number of institutions that replied Institutions that did not treat AN Institutions that did treat AN Reported number of AN Patients Estimated total number of AN Patients Prevalence of AN per 10’ of general population per 10’ of female population per lo5 of 13-29-year-old female population

1985

1992

5283

5057

3397 (64.3%)

1892 (37.4%)

2665 732 (21.6%) 2391

2247

3500-4500

4500-5600

2.9-3.7

3.6-4.5

5.1-8.0

6.3-9.7

20.4-25.3

25.2-30.7

85% of the normal weight group replied that they wanted to lose weight. Even in the lo20%underweight group, 45% said they wanted to lose weight. These data show that a great number of students want to lose weight.

Research 62 (1996)

Table 4 Epidemiological study on bulimia nervosa (BN) in Japan, 1992 Number of surveyed institutions Number of institutions that replied Reported number of BN patients Estimated total number of BN patients Prevalence of BN per lo5 of general population per 10’ of female population per lo5 of 13-29-year-old female population

Want

90

q q

80 70 60

Want

A=

40

B

30

1.332.5 3.2-4.3 12.8- 13.6

to gain

weight

Unconcerned

Weight

50

5057 1892 (37.4%) 1196 1600-3000

Figure 2 shows that anorexia nervosa appears mainly in urban areas. The maximum prevalence of anorexia nervosa in high school in 1985 was 239.8 per 105. We are currently collecting and analysing the 1992 data (Table 5). One of our group reported that the percentage of abnormally high scores (more than 20 points) on the EAT (Eating Attitude Test) in female university students was 5.75%. Crisp (1980) previously reported that the prevalence of anorexia nervosa in British schoolgirls was one (1%) in about 100 aged 16 and over (Table 6).

100

to

lose weight

groups

:

emaciated = thin

C = standard

20

D

10 0

13

II-16

E= /

6%

Weight

= plump obese

A --20%-

-2O%-•+lO%--+lO%-

Fig. 1. The wish to be thin among 1794 high school girls in the Tokyo area (according to present weight).

T. Kuboki et al. I Psychiatry Research 62 (I 996) I I - I6

14

Kyoto

““:n

.

Anorexia

0

Improving

Fukui

Northern

Nara

Table 5 Prevalence

of Kyoto

of anorexia

patients

cases

Prefecture

Kyoto

Osaka Pref. i

Fig. 2. Distribution anorexic patients.

nervosa

nervosa

prefecture

Yamashiro

Area

Prefecture public high school

in female students

according

Currently, bulimia is predominant among eating disorders, 1794 accounting for 4-S% of female university students in the USA. The prevalence of bulimia is high in England, USA and Germany. The prevalence of bulimia nervosa in Japan now is also increasing. Eating disorders are regarded as syndrome or spectrum diseases, and so it is difficult to evaluate the long-term prognosis because of different psychopathologic levels. We studied 20 chronic eating disorder patients (more than 10 years’ duration from the onset) with regard to weight, eating behavior, menstruation, psychological functioning, psychosocial functioning and clinical course. Sixteen patients (80%) shifted from anorexia to bulimia with vomiting in their eating behaviors, and their -bulimia with vomiting continued. Body weight was still persistently below 85% of the average in 65% of subjects (Table 7). Menstrual dysfunction (persisitent amenorrhea, sporadic, irregular) was reported in 16 patients (80%). The most common psychological symptoms were depressive, obsessive-compulsive tendencies at follow-up. The common personality traits had

to reports

of epidemiological

studies

School

District

Reporter

No. of students

No. of patients

Prevalence

Junior high school

lshikawa prefecture Fukui prefecture Nagoya city Kyoto prefecture Sanin district Sapporo city Tokyo metropolis lshikawa prefecture Fukui prefecture Nagoya city Aichi prefecture (countryside) Kyoto prefecture (public schools) Kyoto prefecture (public schools) Kyoto prefecture (private schools) Ohita prefecture

Mizushima et al. Mizuno et al. Tomita et al. Nakai et al. Ohzeki et al. Nakagawa Suematsu et al. Mizushima et al. Mizuno et al. Tomita et al. Tomita et al.

21153 12 179 13762 5005 18040 13009 1799 15250 12674 11084 73 553

7 1 9 12 15 3 1 9 5 13 8

33.1 8.2 65.4 239.8 83.1 23.1 55.6 59.0 39.5 117.3 10.9

19250

28

145.5

Nakai et al.

6476

9

139.0

Nakai et al.

8491

2

23.6

Suematsu

5101

4

78.4

Senior high school

et al.

(per 10’)

T. Kuboki et al. IPsychiatry Research 62 (1996)

15

II-16

Table 6 Prevalence of anorexia nervosa Prevalence (per 10’)

Remarks

Subjects

Nation

Year

Population

Number surveyed (No. of patients)

Throughout country

Japan

1985

14243381

2900-3600

Case history from Mayo Clinic, School girls aged 16 and over Ishikawa prefecture (junior high school) Kyoto prefecture (junior high school) Case history record

USA

1935-1979

23OOC-58000

2654

301.4

Estimated number of AN patients surveyed at hospitals having more than 200 beds Lucas et al.

Britain

1972-1974

12391

to50

Crisp

Japan

1981

21153

41.6

Japan

1983

5005

239.8

Switzerland

1956- 1958

83 500

(10)

3.98

1963-1965 1973-1975

83 500 75600

(17) (38)

6.79 16.76

obsessive-compulsive, avoidant, and borderline features. In particular, patients who were associated with bulimia and vomiting often act out and abuse themselves. They were diagnosed as having borderline personality disorder. Most patients remained poorly adjusted socially. Their relationships with families and with other people were quite impaired (see Table 8 for outcome data).

Mizushima et al.

Nakai et al.

Willi et al.

(6) No known physical illness that would account for weight loss. An epidemiological survey on anorexia nervosa was performed in 1985 and 1992 in Japanese hospitals using a questionnaire. The reported number of patients with anorexia nervosa was 2391 from 732 institutions. From these data, the total number of anorexia nervosa patients treated Table 7 Subject (n = 20, all female) n

Range

Mean

Present age (years) Onset age (years)

26-48 12-24

Duration of illness (years) Marriage Not married Married Occupation Full-time employment Part-time employment Unemployment Housewife

IO-30

34.0 17.8 (after 20 yrs, n = 7) 15.6

5. Conclusion The diagnostic criteria for anorexia nervosa of the research group sponsored by the Japanese Ministry of Health and Welfare have been revised in accordance with DSM-III-R as follows: (1) A loss of 20% or more of standard body weight. (2) Eating disorders. (3) A distorted cognition of body weight or shape (an intense fear of gaining weight). (4) Age at onset below 30 years of age. (5) In females, amenorrhea.

20.4-25.3

14 6 3 3 9 5

T. Kuhoki et 01. I Psychiatry Research 62 (1996)

16

Table 8 Eating behavior

outcome

Pattern

n (%)

Anorexia (A) dominant (restrictor) A + bulimia (B)” + vomiting (V), normal

weight

(within 15%) A -+ B” + V, low weight (below 85%) A -+ B + A + B” (involve), low weight A+B+V Other “A + B interval,

about

3 months

to 4 years, mean

4 (20) 5 (25) 5 (25) 3 (15) 2 (10) 1 (5) 1.5 years.

in 1985 in Japanese hospitals was estimated to be about 3500-4500. In 1992, the reported number of patients with AN was 2247. The total number of AN patients treated in 1992 was estimated to be about 4500-5600, which is a little higher than that in 1985 (3500-4500). References American Psychiatric Association (1987) Dingnostic and Statistical Mutual of Mental Disordew7hird Edition-Revised (DSM-111-R). American Psychiatric Association, Washington, DC. Aoki, H. (1986) Morbidity and therapy of anorexia nervosa-from the standpoint of cognition-behavior theory (in Japanese). Psychosomatics 26 (2), 149-160. Azuma, T. (1988) Questionaire investigation on anorexia nervosa in high school girls in Kyoto prefecture, Japan. Central Eating Disorder Research Committee, supported by the Ministry of Health and Welfare, Japan, Annual Report, 19-25. Bruch, H. (1970) Instinct and interpersonal experience. Campr Psychiatry 11, 495-506. Crisp, A.H. (1980) Anorexia Nrruosa- Lrt Me Be. Academic Press, London.

I I-16

Garfinkel, P.E. (1980) The heterogeneity of anorexia nervosa: bulimia as a distinct subgroup. Arch Gen Psychiutry 37, 1036- 1040. Garfinkel, P.E., Kaplan, AS., Garner, D.M. and Darby, P.L. (1983) The differentiation of vomiting and weight loss as a conversion disorder from anorexia nervosa. Am J Psychiatry 140, 1019-1022. Kuboki, T. and Suematsu, H. (1993) Anorexia nervosa, clinical statistics of Japan (in Japanese), Nihon Rinsyo 51 (Suppl), 3-10. Minuchin, S., Roseman, B.L. and Baker, L. (1978) Psychosomatic Families; Anorexia Nervosu in Context. Harvard University Press, Cambridge, Massachusetts, London. Suematsu, H. (1988) The second nationwide survey of anorexia nervosa (in Japanese). Research group on anorexia nervosa sponsored by the Ministry of Health and Welfare, Japan. Report far 198cI, pp. 19-25 . Suematsu, H. (1989-90) New diagnostic criteria for anorexia nervosa (in Japanese). Research group on anorexia nervosa sponsored by the Ministry of Health and Welfare, Japan. Report for 1989-1990, pp. 1177122. Suematsu, H. (1990) Eating disorders. Asian Med J 33 (3), 155-158. Suematsu, H., Ishikawa, H., Kuboki, T. and Ito, T. (1985) Statistical studies on anorexia nervosa in Japan; detailed clinical data on 1011 patients. Psychother Psychosom 43, 93- 103. Suematsu, H. and Kuboki, T. (1989) Endocrinological aspects of psychosomatic disorder-in particular anorexia nervosa (in Japanese). Harm C/in 37, 1059- 1063. Suematsu, H., Kuboki, T. and Ito, H. (1985) Statistical studies on the prognosis of anorexia nervosa. Psychother Psychosom 43, 104-l 12. Suematsu, H., Kuboki, T. and Ogata, E. (1986) Anorexia nervosa in monozygotic twins. Psychother Psychosom 45, 46- 50. Suematsu, H. and Kuboki, T. (1991) Eating disorders and antianxiety agents. Asian Med J 34 (IO), 593-596. Theander, S. (1985) Outcome and prognosis in anorexia nervosa and bulimia; some results of previous investigation. as compared with those of a Swedish long-term study. .I Psychiutr Res 19, 4933508.