The Japanese Journal of Psychiatry and Neurology, Vol. 46, No. 4, 1992
Bulimia Nervosa in a Pair of Male Monozygotic Twins Hidemi Iwasaka, M.D., Junzo Iida, M.D., Youko Kawabata, Hiroshi Kitamura, M.D., Katsuki Kitera, M.D., Fumio Hirao, M.D., Genro Ikawa, M.D. and Kenichi Hashino, M.D. * Department of Psychiatry, Nara Medical University, Nara
* Shimoichi Hospital, Nara
Abstract: This is a report of a pair of male monozygotic twins meeting the DSM-111-R criteria for bulimia nervosa. At the age of IS, both brothers began to diet and suffered from bulimia. They were admitted to psychiatric hospitals and separated. After admission, their clinical course dramatically changed. The differences in their clinical courses and endocrinological data are suggestive as to the roles of environmental and hereditary factors in the etiology of bulimia nervosa. Key Words : bulimia nervosa, male, monozygotic twin, testosterone, etiolop Jpn J Psychiatr Neurol46: 853-858, 1992
INTRODUCTION Several articles have reported on twins with anorexia nervosa or bulimia nervosa, with discussion on the etiology. The crux of the matter is whether hereditary or environmental factors are more important. Dowson et al.’ reported male identical twins concordant for anorexia nervosa and suggested that environmental factors were more important. Kaminer et a1.’ reported female monozygotic twins concordant for bulimia nervosa and suggested that genetic factors as well as environmental factors played a potential role in the etiology and course of the disorder. Fichter et d 3analyzed the concordance rates for 27 pairs of twins Received for publication on April 30, 1992. Mailing address: Hidemi Iwasaka, M.D., Department of Psychiatry, Nara Medical University, Shijo-cho, Kashihara, Nara 634, Japan.
with bulimia nervosa, including one monozygotic male pair discordant for bulimia nervosa. Previous reports of male identical twins concordant for bulimia nervosa have not been found. In the present case, both male twins were diagnosed with anorexia nervosa and bulimia nervosa by the DSM-111-R rite ria.^ This rare case is reported with discussion of the etiology of bulimia nervosa according to the patients’ clinical course and endocrinological data. CASE REPORT The twins’ father is the manager of a landscape gardening business and a member of the local government. He is a big, muscular man; he is rigid, moralistic and exceedingly authoritarian. The mother is a housewife and a stout woman. She manages her household effectively, but she appears cool and inaccessible. The
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twins had an elder brother but he died at birth. The twins live with their parents and grandparents. There is no psychiatric illness in their family or relatives. Twin A, born first (weight: 3,050 g) after a normal pregnancy and forceps delivery, followed by twin B (weight: 2,600 g) after a natural delivery. They were bottle fed and cared for by their mother. Early development was uneventful. There were no feeding difficulties and no history of struggles on eating. From their childhood, the twins competed with each other. However, in sports and study, A was the more dominant partner in a close and exclusive relationship with B. After entering junior high school in 1986, the twins began to take separate paths. (Table 1) Both A and B entered the baseball club together, but B gave up baseball one year later, started delinquent behavior and dropped out. A was then excessively pushed by his parents to succeed. That is, A was in a persistently stressful environment, while B was more easygoing and relaxed. A did his best compulsively, but failed to become a regular player and was very disappointed. During the summer of 1988, A became de-
Table 1 : History of the Present Illness A 1986 Apr . (at age 13) 1987 Apr.
1988 Aug. Oct.
Entering baseball club together Excessive expectation by parents Depressive state Start of diet (56 kg)
1989 Apr. Mar.
Jul . 1990 Jan. Mar. (at age 16)
pressive. In October he started to reduce his intake of food gradually, because he began to be preoccupied with a desire to be slim. By the spring of 1989, his weight had fallen from 56 kg to 38 kg. At that time, he quit high school and began to work at his father’s enterprise. Then he began to eat huge amounts of food and induce vomiting after meals, to prevent weight gain. He managed to keep his eating disorder a secret from everybody except B. In August 1989 he stopped working and socially withdrew. Twin B soon followed the same course. That is, B started to diet in April 1989, because he thought that A’s slender body looked good. By July 1989, his weight had fallen from 60 kg to 45 kg. Then he began to imitate A’s bulimic behavior. In January 1990, A’s bulimic symptoms became severe. He spent most of the time cooking, binge-eating and self-induced vomiting, even in front of his parents. Soon B imitated A’s behavior. They quarreled with each other about food; for example, who could use the kitchen for cooking or the bathroom for vomiting. Their fighting about food continued every day for 3 months. So they were admitted to different psychiatric hospitals and separated from each other on the 27th of May 1990, at the age of 16. On admission, A did not verbalize an intense fear of fatness, but his behavior proved his excessive interest in thinness. B verbalized that he wanted to be as thin as A.
Table 2 : Zygosity A
Start of diet (60kg) Start of binge eating (38 kg) Start of binge eating (45 kg) Change for the Change for the worse worse Admission
Blood type ABO
Rh MN Lewis HLA
M Le ( a - b + ) A2 A24 (9) B51 (3) BW52 (5) 46XY
M Le ( a - b + ) A2 A24 (9) B51 ( 3 ) BW52 ( 5 ) 46XY
Bulimia in Male Twins LH m p o n H to LH-RH In A
LH meponw to LH-RH In B
w before treatment *-a
before treatment eltor troetment
TSH r e e p o n u to TRH in A CI
Fig. 1: LH response to LH-RH in A. LH response to LH-RH in B.
T$H rm8ponu to TRH h 0
bofore treatment after troatmant
before treatment after treatment
Fig. 2: TSH response 0
Physical examinations on admission: A’s height was 173.8 cm and the body weight was 44.5 kg. B’s height was 172.0 cm and the body weight was 45.0 kg. There were no remarkable signs or symptoms, except for self-starvation. The laboratory data showed no particular differences. Zygosity was established by marker studies such as the blood type. (Table 2) Endocrinological tests were then conducted twice by immunoradiometric assay. The first was performed on admission, the second 4 months later when A was still emaciated (40kg) and B had recovered ( 5 5 kg). The results are shown in Figs. 1 and 2. Before treatment, A showed a low LH response after intravenous administration of 0.1 mg LH-RH. After treatment, A showed a lower LH response than before treatment. By contrast, B showed low LH responses to
to TRH in A. TSH response to TRH in B.
LH-RH both times. Before and after treatment, A showed low TSH responses after intravenous administration of 0.5 mg TRH. By contrast, B showed a low TSH response to TRH after treatment, while he showed a normal TSH response before treatment. Furthermore, only A showed a low value for serum testosterone during admission. The endocrinological data revealed that A was more severe than B in endocrinological abnormalities. However, B s abnormalities were not correlative to his weight. The results of psychological tests, such as the Rorschach test, showed almost the same tendency, that is, a higher demand, lower products, and a tendency to be influenced by others. B showed lower reactions than A. The intelligence quotient (IQ) of A was 101 by WAIS; that of B was 88. After their admission, the twins were in-
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tentionally treated with the same medicines and similar supportive psychotherapy. However, the clinical course of them became dramatically different. B's symptoms of bulimia decreased quickly and his weight had recovered to 55 kg in a month. Four months after admission, B was discharged. On the other hand, A's symptoms continued and his weight remained poor. Afterwards A was treated with sand-play treatment and it was effective. At first he used a few materials, only within a limited area, but as his condition gradually improved, the area he used grew proportionally. Eight months after admission, A was discharged weighing 39 kg. However, 2 months later A changed for the worse, and showed the same symptoms as before. B, thought to be in remission, once more imitated A's behavior. Because their fighting about food escalated, A was admitted to the psychiatric hospital and B remained at home. After that, A has suffered from many symptoms of bulimia, while B has had a good clinical course without any direct therapy. DISCUSSION
Since Beumont ( 1972)5 reported 25 male cases of anorexia nervosa, reports of eating disorder in males have been increasing. Recently Carlat et al. (1991)6 reviewed the literature of bulimia nervosa in males and identified the characteristics of male bulimics, that is, later age of onset, higher prevalences of premorbid obesity, homosexuality, asexuality, and less concern with strict weight control. In Japan, Shimosaka (1966) reported the first male case of anorexia nervosa. Sakai et al.' reported a case of anorexia nervosa in one of male dizygotic twins and Akagi et aZ.* reported a case of male monozygotic twins discordant for anorexia nervosa. Kiliike et aL9 reported 4 cases of bulimia in males and discussed the difficulty in establishing a good doctor-patient relationship. Takizawa" investigated 25 male patients with eating disturbances and supposed that the main psycho-
pathology of typical eating disorder was egoidentity confusion and withdrawal from or evasion of undertaking the social role of the masculine gender. There are several papers which compare the incidence of concordant cases of anorexia nervosa or bulimia nervosa between monozygotic and dizygotic twins. The higher concordance rates in monozygotic twins for disorders, found in past studies, revealed the importance of hereditary factors in the etiology. Holland et al." l2 noted the existence of genetic vulnerability that could develop into an eating disorder under conditions of stress. On the other hand, Suematsu et al.13 suggested that hereditary factors could not determine the etiology of anorexia nervosa because of the difference in quality or degree in the concordant cases . Hsu et aLi4investigated 11 sets of twins (6 monozygotic, 5 dizygotic) with bulimia nervosa and discussed the genetic predisposition mechanism. Kendler et aLI5 conducted psychiatric interviews with 2,163 female twins and investigated the genetic epidemiology of bulimia nervosa. But the risk for bulimia has not been reported separately for female and male subjects. In the present case, endocrinological abnormalities of B, similar to those of A, continued even after the recovered state. Kiliike et all6 suggested certain primary abnormalities in the hypothalamic-pituitary axis in bulimia in normal weight. For that reason, both A and B are considered to have the same underlying biological abnormalities. That is, the twins' endocrinological data suggest that biological vulnerability due to hereditary factors is involved in the etiology of bulimia nervosa. However, the severities and clinical courses of the twins were very different. Both A and B grew up in a strict home peculiar to Japanese society, and their parents considered the elder brother always superior to the younger. A was, therefore, consistently pressured by the stressful environment, especially by his father, who says: "I have never pushed the
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boys, but it is important that they do their best in whatever they do. I know they are capable of being good.” A tried to reach manhood in Japanese society, and was exposed to the particular challenge of separation from his dependence upon his father, and failed. Oshima et al.” and Yokoyama et aL’* stated that sand-play treatment was useful in establishing ego-identity in anorexia nervosa through the nonverbal approach. Actually sand-play treatment was effective for A. Twin B, however, suffered from bulimia again during collective life with A, and recovered as a result of separation from A. For that reason, it is suggested that environmental factors are also important in the etiology and the course of bulimia nervosa. Based on this case, predicting factors of bulimia nervosa are discussed. It is true that twins A and B had the same biological vulnerability, but there were some differences between them. A had never verbalized his distorted body image. That is, he had no insight into disease. A had a long duration of anorexia and bulimia before treatment. Even after admission, he had a long duration of emaciation and showed a low value for serum testosterone. Frankel et al.19reported a male case of anorexia nervosa showing a low value for plasma testosterone during emaciation. Beumont et al. suggested that a disorder of the urinary excretion levels of testosterone in male patients was comparable to the menstrual disturbance of female patients with anorexia nervosa. It is considered that a low value for serum testosterone is a predicting factor for a poor prognosis of bulimia nervosa in males, but further investigation is needed. CONCLUSION
The simultaneous onset of bulimia nervosa in monozygotic male twins and the dramatic change in the course of the disorder in each is reported. The twins’ endocrinological abnormalities suggest that biological vulnerability due to hereditary factors is involved in the etiology of bulimia nervosa. The differences
in the twins’ clinical courses suggest that environmental factors are also important in the etiology of this condition. REFERENCES 1. Dowson, J.H.: Anorexia nervosa in a male identical twin. Bril J Clin Pract 31: 80-81, 1977.
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