Schizophrenia In Japan Research Articles

Dopamine D1 receptor gene polymorphism and schizophrenia in Japan.

We studied the relationship between schizophrenia and the DdeI polymorphism in the 5' untranslated region (5'UTR) of the dopamine D1 receptor (DRD1) gene. This polymorphism is an A (A1 allele) to G (A2 allele) transition in the 5' UTR of exon 2 at bp -48 (A-48G). One hundred forty-eight schizophrenics and 148 control subjects were investigated. No significant differences in genotypic counts and allele frequencies between schizophrenics and controls were found. Although a significant difference between the patients classified as disorganized type and the controls was discovered both in genotypic counts and allele frequencies, neither association proved significant when a Bonferroni correction was used. Moreover, there were no differences in scores of main symptoms of schizophrenia based on the Manchester Scale between patients with A1/A1 genotype and those with A1/A2 genotype. These findings suggest that this gene may not be involved in the pathogenesis of schizophrenia.

Algorithm for the treatment of schizophrenia in Japan

Evidence-based psychopharmacological algorithms for the treatment of patients with schizophrenia have been developed in many countries in the last decade. While it would be of interest to consider a common algorithm based on international consensus, algorithms and information on antipsychotics available in each country are limited. Inspired by the algorithm generated by the International Psychopharmacology Algorithm (IPA) Project, this algorithm for the treatment of schizophrenia has been developed by the Japan Psychophamacology Algorithm (JPA) Project. New antipsychotics, such as clozapine, olanzapine and quetiapine, are excluded from this algorithm, being currently unavailable in Japan. In the end there was no essential difference between the algorithms for the treatment of acute schizophrenic episodes. However, combined use of antipsychotics appears to be more common in Japan and the adjunctive use of L-DOPS or thyrotropin-releasing hormone is included in the JPA algorithm for the treatment of drug-refractory schizophrenia.

Negative Association between T102C Polymorphism of the 5-HT2a Receptor Gene and Schizophrenia in Japan

Serotonin (5-hydroxytryptamine, 5-HT) may play an important role in the pathogenesis of schizophrenia. Previous studies suggested that the efficacy of atypical neuroleptic drugs (e.g., risperidone and clozapine) on negative symptoms may be related to the 5-HT_2a receptor. Although association studies between MspI polymorphism (T102C) and the 5-HT_2a receptor gene and schizophrenia have been reported, their results are still controversial. The aim of this study was to examine the association between T102C polymorphism of the 5-HT_2a receptor gene and schizophrenia as well as the association between the polymorphism and negative symptoms in a Japanese population (106 patients with schizophrenia and 109 healthy controls). No significant positive associations were observed. Our results suggest that the 5-HT_2a receptor gene is not involved in the pathogenesis of schizophrenia or negative symptoms.

Neurochemical studies of schizophrenia in Japan.

Neurobiological research in schizophrenia has been hampered by several confounding factors such as the heterogeneity of the illness and the paucity of biological markers. Recent progress in research methods, however, has enabled the improvement in our understanding its pathophysiology. This paper reviews recent neurochemical investigations of schizophrenia and its animal models which were conducted in Japan in the last decade. The research areas reviewed are (i) monoamine and their metabolites in body fluids, (ii) phospholipids and prostaglandins, (iii) neurochemistry in autopsy brains, (iv) immunological measures, (v) magnetic resonance spectroscopy, (vi) regional cerebral blood flows (rCBF), (vii) molecular genetics, and (viii) animal models. It is worth noting that there exist abnormalities of amino acidergic (glutamatergic and GABAergic) neurotransmission as well as monoaminergic (dopaminergic and serotonergic) one in postmortem schizophrenic brains. These abnormalities and also the findings of altered rCBF indicate the existence of disturbed neuronal circuits that contribute to the diverse symptoms of schizophrenia. Also, dysfunction of membrane phospholipids derived from studies on magnetic resonance spectroscopy may underlie negative symptoms in schizophrenia. Given that schizophrenia is considered to comprise a group of disorders with a diverse heterogeneity of etiologies, research in the next decade is expected to identify putative genes that are involved in vulnerability to schizophrenic phenotype.

Expressed emotion among families and course of schizophrenia in Japan: A 2-year cohort study

A 2-year cohort study was conducted to determine whether expressed emotion (EE) in families is associated with relapse of schizophrenia in Japan. Key relatives of 52 schizophrenic patients were interviewed using the Camberwell Family Interview (CFI) and the patients were classified into high and low EE groups. The 2-year relapse risks were 71% (17/24) in the high EE group and 37% (10/27) in the low EE group. The risk ratio was 1.9 and the 95% confidence interval (CI) ranged from 1.1 to 3.3. In the multiple logistic regression analysis, the odds ratio between families' EE and schizophrenic relapse was 4.6, controlling for other potential confounding factors. It was concluded that, in Japan, the families' EE is a good predictor for schizophrenic relapse within 2 years. This association between EE and relapse could be due to the strong difference in the first 9 months. The period during which EE's predictive validity for schizophrenic relapse is applicable may vary according to the society to which the patients and their families belong.

Studies on relapse, course and outcome of schizophrenia in Japan.

Studies of the long-term outcome of schizophrenia in Japan are reviewed. In nine studies over a 10 year period, recent reports on three patient cohorts show that the liability to relapse is the major difficulty in the treatment and care of schizophrenia. Other research on relapse-related problems in schizophrenia are also reviewed. Relapses appear mainly in the first decade after onset of the condition; in stressful situations related to a family or larger social context; and on cessation of psychotropic drugs. Relapse liability develops during the course of schizophrenia, but the characteristics of the relapses vary with both the duration and the episodic nature of the schizophrenic condition. Two types of unique treatments that are specifically aimed at coping with relapses, and which were developed in Japan, are described: 'Seikatsu-Rinsho' (clinical guidance to the way of life) and 'Soegi-Ryoho' (splint therapy).

War induced posttraumatic stress disorder in out patient psychiatric treatment

The reliability of expressed emotion (EE) ratings by the Camberwell Family Interview (CFI) and characteristics of EE were evaluated in families of patients with mood disorders in Japan. The subjects were 27 patients with mood disorders and 31 members of their families. The CFI was carried out with the family members. EE was rated by two raters independently, and the inter-rater reliability was evaluated according to Spearman’s correlation coefficient by ranks and the κ-value. The distribution of subscales of EE in these subjects was compared with that in families of patients with schizophrenia in Japan and families of patients with mood disorders abroad. Concerning critical comments (CC), hostility (H), and emotional over-involvement (EOI), which are important for EE rating, Spearman’s correlation coefficient and the κ-values were 0.4–0.8, and the reliability of EE ratings in mood disorders was not high. The proportion of positive agreement was particularly low in H and EOI. CCs were fewer in families of Japanese patients with mood disorders than in those with schizophrenia or families of American or European patients with mood disorders. Re-evaluation of the inter-rater reliability of EE ratings in mood disorders is needed. Expressed emotion was more suppressed in families of patients with mood disorders than in those of patients with schizophrenia. Expressed emotion was also more reserved in the Japanese subjects than in their Western counterparts.

Expressed emotion and the course of schizophrenia in Japan.

We examined whether expressed emotion (EE) influenced the course of schizophrenia in Japan. We conducted a cohort study. Of 73 subjects with schizophrenia meeting the diagnostic criteria of ICD-9 or DSM-III-R, 52 participated in the study. The Camberwell Family Interview was conducted to evaluate EE. The subjects had been followed up for nine months and psychiatrists who were blind to the EE status evaluated their symptoms with the Brief Psychiatric Rating Scale. The relapse rate in the high-EE group was 58% and that in the low-EE group 21% (P < 0.01). Nine-month relapse risk ratio was 2.72 (95% CI 1.24 to 5.97). CONCLUSION. In Japan, as elsewhere, EE is a good predictor of schizophrenic relapse.

Behavioral and neuroimaging studies on schizophrenia in Japan

Chronic methamphetamine psychotics became a major problem in Japan after World War II. On one hand, the clinical symptoms of chronic methamphetamine psychotics were noted to resemble those of schizophrenics quite closely but, on the other hand, their respective personality profiles appeared to differ. Recent research on exploratory eye movements has also shown such similarities and differences. In long-term remitted chronic methamphetamine psychotics, extremely small doses of drugs, or stress, can be enough to cause a recurrence of symptoms. This phenomenon resembles the recurrence of schizophrenia, and animal experiments and basic research are being actively conducted in order to elucidate the mechanism involved. Some 20 years ago, unique studies were conducted that objectively looked at the characteristic behavior of severe chronic schizophrenics in a playground situation. Exploratory eye movements can also be regarded as a kind of behavior and, in this paper, eye movement patterns made in response to a maze test are discussed. In addition, much research on brain imaging in schizophrenia is being conducted in Japan and several interesting studies have also been chosen by the authors for presentation in this paper.

Hebephrenia as the most prevalent subtype of schizophrenia in Japan.

The author reviewed the frequency of the hebephrenic subtype compared to the paranoid subtype diagnosis of schizophrenia in Japan, using research papers and statistical reports that have been published during this century. It was found that the reported rates for the hebephrenic subtype ranged from a low of 23% to a high of 68% with the majority falling between 30% and 50%. These rates had not varied significantly over a long period of time or across wide geographical areas. It was discussed that Japanese psychiatrists were so sensitive to the negative symptoms of schizophrenia that they had a broader concept of hebephrenia as compared to other Kraepelian subtypes in schizophrenia.

Epidemiological studies of schizophrenia in Japan.

This article examines epidemiological studies of schizophrenia in Japan. It is divided into three major sections: (1) methodological problems associated with epidemiological studies; (2) an overview of the history of epidemiology in Japan; and (3) an epidemiological study on incidence rates in Nagasaki, which was conducted as part of the World Health Organization Collaborative Study on Determinants of Outcome of Severe Mental Disorders. In general, although some differences in schizophrenic subtypes have been found, prevalence and incidence rates of schizophrenia in Japan are not significantly different from those reported in other countries.

A long-term follow-up study of schizophrenia in Japan--with special reference to the course of social adjustment.

A 21-27-year follow-up was conducted on 140 schizophrenic patients consecutively discharged from the Department of Neuropsychiatry, Gunma University Hospital, between 1958 and 1962, and 130 patients (93%) were successfully evaluated. Of these patients, 105 were still living, and the longitudinal courses could be fully observed in 98. With regard to the social outcome of the 105 patients, 47% were assessed as 'self-supportive' whereas 31% were 'hospitalised'. As for psychopathological outcome, 31% were 'recovered', 46% were 'improved', and 23% were 'unimproved'. In the studies of the longitudinal courses of the 98 patients, fluctuating courses of social adjustment were the most numerous in the early stages, whereas in the later stages many of the patients showed differentiation in one of two directions, namely the 'stable self-supportive' state and the 'chronic institutionalised' state. However, this form of differentiation was not revealed in the distribution of psychopathological 'end states'.

Present status of the psychotherapy of schizophrenia in Japan.

Present status of the psychotherapy of schizophrenia in Japan.