Hiroko Mizushima

Association between dopamine D4 receptor (D4DR) Exon III polymorphism and novelty seeking in Japanese subjects

This study was designed to assess the association between novelty seeking and D4DR gene polymorphism in the Japanese population. The 48 bp repeat polymorphism in the third exon of the dopamine D4 receptor gene of 153 normal female students was correlated with personality feature results from the Japanese version of Cloningers Temperament and Character Inventory. The Novelty Seeking subscale of Exploratory Excitability had a significant association with long alleles of the polymorphic exon III repeat sequence of D4DR. Our results suggest that there is an association between long alleles of the polymorphic exon III repeat sequence of D4DR and the personality traits of the Novelty Seeking subscale of Exploratory Excitability, regardless of racial differences in the frequencies of D4DR exon III repeat polymorphism.

Use of herbal medicine for treating psychiatric disorders in Japan

Alongside the Western pharmacotherapy that is now the major medical modality in Japan, we continue to offer a number of traditional remedies. We prefer to allow patients to choose between these two approaches, after explaining the advantages and potential adverse effects of each. Research into the traditional treatments continues, and we now have a number of studies available concerning the efficacy of oriental herbal medicine (Kampo medicine) in Japan. There are about 120 different prescriptions available for treatment. Herbs are believed to affect both the psyche and soma, and Kampo medicine does not differentiate between them. Improvement brought about by herbal medicine is usually mild and slow, but sometimes very drastic. Side effects are rare. Those that do occur are mostly allergic reactions to natural substances. Therefore, herbal medicine is especially useful for elderly patients and patients with physical complications. Prescription is traditionally selected by judging Sho of a patient. Sho is equivalent to a syndrome, but comprises psycho and somatic symptoms and signs obtained by traditional physical examination that focuses constitution, general physical condition, pulse, abdominal signs, and examination of the tang. However, currently modern diagnoses are also applied to deciding upon the prescription. Western physicians can select the appropriate preparation without having a special knowledge of Oriental medicine.

Environmental and Possible Genetic Contributions to Character Dimensions of Personality

The relationship between dimensions of personality characteristics and the perceived rearing attitude of parents in the Japanese population were investigated. The scores on a measure of perceived parental attitude of 153 normal female students, measured on the Parker Parental Bonding Instrument, were correlated with personality features from the Japanese version of the Cloninger Temperament and Character Inventory. Self-directedness, especially the subclasses of Responsibility vs Blaming and Congruent Second Nature vs Incongruent Habits, was significantly related to high scores on Maternal Care and low scores on Maternal Overprotection. The subscale of Self-acceptance vs Self-striving correlated only with low scores on Maternal Overprotection. Paternal Care was only related to the total scale scores on Self-directedness. Results suggest that some personality traits may be related to the perceived attitudes of parents, especially of the mother, during childhood.

TCI temperamental scores in bulimia nervosa patients and normal women with and without diet experiences

In order to distinguish the trigger and the factors maintaining bulimia nervosa (BN), TCI temperamental scores were compared among BN patients, normal controls without diet experiences (N‐N), and normal controls with diet experiences (N‐D). On the novelty‐seeking (NS) scale, the BN patients scored significantly higher than the N‐N subjects, but there was no significant difference between the BN patients and the N‐D subjects, and the N‐D subjects scored higher than the N‐N subjects. These findings suggest that high NS scores are related to diet experiences rather than chronic bulimic symptoms.

Plasma nitrate and nitrite levels of patients with eating disorders

However, little is known about the relationship of NO and eating disorders (ED). The aim of the present study was to test whether the level of NO production in the bodies of patients with ED is different from that of normal controls. Because the half-life of NO is too short in vivo to measure directly, we investigated the levels of nitrite and nitrate, markers of NO production in vivo , 5 in the plasma of ED patients and healthy controls. The present study was conducted upon approval from the Ethics Committee of the Department of Neuropsychiatry, Keio University. Full explanation of the procedures was provided to the patients involved and informed consent was obtained in writing. The study subjects consisted of seven female outpatients who met the Diagnostic and Statistical Manual of Mental Disorders (4th edn; DSM-IV) criteria for ED not otherwise specified and 12 healthy female volunteers (controls). None of the patients took antipsychotics, anxiolytics, or hypnotics for at least 2 weeks prior to blood collection, except one, who took an antidepressant, fluvoxamine (200 mg/day). All healthy controls were psychotropic-naive. Subjects with history of drug abuse, diseases (blood, neurologic, hepatic, and cardiovasculorenal), or other conditions that may have influenced their plasma nitrite/nitrate levels were excluded. All subjects except one (10 cigarettes/day) were nonsmokers. Liver and renal functions, and cell count were determined with same blood samples, and it was confirmed that the findings remained within normal limits. Subjects refrained from alcohol and food intake, and physical exercise after 20:00 hours of the day before blood collection, which was performed between 10:00 and 12:00 hours. Data that excluded patients who took psychotropics and the aforementioned smoker were also analyzed, although this did not substantially change the overall findings. All data are expressed as mean ± standard deviation (SD) and were analyzed with Student’s t -test. The mean ages of ED patients and controls were 23.1 ± 3.6 and 24.7 ± 5.6 years, respectively. Heights and weights of ED patients and controls were 157.4 ± 4.9 and 154.3 ± 5.6 cm, and 51.6 ± 15.1 and 49.9 ± 6.9 kg, respectively. The plasma nitrite levels of ED patients and controls were 4.56 ± 10.0 and 6.99 ± 5.55 m mol/L, respectively. The plasma nitrate levels of ED patients and controls were 43.0 ± 9.7 and 67.7 ± 48.3 m mol/L, respectively. Neither plasma nitrite levels (t = 1.85; P = 0.08) nor plasma nitrate levels (t = 1.32; P = 0.20) were significantly different between ED patients and controls. The pathogenesis of ED remains unclear, although there is accumulating evidence of the NO system’s involvement in food intake. 6 Squadrito et al . showed that an NO synthase inhibitor dose-dependently induces the reduction of food intake and subsequently weight loss in rats. 7 Also induced is a concomitant reduction of NOS activity in the nuclei, which are known to regulate satiety. Therefore, it can be hypothesized that the amount of NO production is different between patients with ED and healthy controls. However, this was not shown to be the case because the data obtained from the present study did not support the hypothesis. However, there are some different characteristics in the subtypes of ED. 8 One possible reason for the study’s failure to find differences in plasma nitrite/nitrate levels between the groups is that the patients tested in the present study were not limited to those with either bulimia or anorexia nervosa. Because NO is involved in physiologic food intake as aforementioned, an examination in which plasma nitrite/nitrate levels are compared between patients with bulimia and those with anorexia nervosa, should be carried out.

Personality as a Vulnerability Factor in Eating Disorders

We performed a study to distinguish the trigger of and the factors maintaining bulimia nervosa (BN). The subjects were BN patients, normal women without diet experiences, and normal women with diet experiences. We used the Temperament and Character Inventory scales (TCI) as the instrument. As a result, a high Novelty Seeking score (NS) is identified as the main characteristic of BN, and a high Harm Avoidance score (HA) is assumed to contribute to maintaining bulimic symptoms. As the sociocultural background for eating disorders (ED), there may be pressure on women to be thin to be attractive. Also, ED patients have often been pointed out as having problems with interpersonal relationships. We assume that under sociocultural pressure those women having disordered interpersonal relationships with certain contributing personality factors may develop a diet and ED including BN. Our result using TCI may show that women with high NS go on a diet and women whose HA is also high develop BN in our modern culture.

The Use of Japanese Herbal Medicine in the Treatment of Somatoform Disorders

It has been observed that Japanese herbal medicine (Kampo medicine), with its philosophy that every disease is psychosomatic in origin and that herbs affect both the psyche and the soma, sometimes has a dramatic effect on somatoform disorders, although there has been no systematic study examining the effects of Kampo on somatoform disorders. We conducted a preliminary study in the Keio Kampo Clinic, which revealed that 65% of the patients had unexplained physical symptoms. This study suggests that Kampo plays an important role in the treatment of somatoform disorders in Japan. In Kampo medicine, every patient is prescribed a Kampo formula according to his/her Sho. Sho is equivalent to a syndrome, but it comprises psychic and somatic symptoms and signs obtained by a set of traditional physical examinations that take the patient’s constitution into account. Thus, somatoform patients are treated in the same way as nonsomatoform patients, which may give them more satisfaction.