Seiichi Harada

A genetic variation in the dysbindin gene (DTNBP1) is associated with memory performance in healthy controls

Schizophrenia is a common psychiatric disorder characterized by disturbances of cognition, emotion and social functioning. There are few studies investigating a possible genetic basis for the underlying mechanism of cognitive dysfunctions. A genetic variation in the dysbindin gene (DTNBP1: dystrobrevin binding protein 1), a susceptibility gene for schizophrenia, has been reported to be associated with general cognitive ability and cognitive decline in patients with schizophrenia. Although profound disturbances of memory performance are observed in schizophrenia, only one study has reported a relationship between this gene and spatial working memory in a Caucasian population. We examined a possible association between a protective haplotype of DTNBP1 for developing schizophrenia and memory performance measured by the Wechsler Memory Scale-Revised (WMS-R) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) in 165 healthy volunteers and 70 patients with schizophrenia in a Japanese population. Healthy controls that carry the protective haplotype showed higher performance in several memory domains measured by the WMS-R than those who did not. Genotype effect on memory performance was not observed in patients with schizophrenia. This haplotype did not affect IQ and its sub-scores as measured by the Wechsler Adult Intelligence Scale-Revised in both groups. These data suggest that DTNBP1 may have impact on parts of memory functions.

Type of feeding during infancy and later development of schizophrenia

Nutrition may be critical for neurodevelopment and can affect the later development of schizophrenia. Recently, a marked reduction in breast-feeding was reported in infants that developed schizophrenia in later life (McCreadie, R.G., 1997. The Nithsdale Schizophrenia Surveys. 16. Breast-feeding and schizophrenia: preliminary results and hypothesis. Br. J. Psychiatr. 170, 334-337). In the present study, we investigated feeding patterns during the infancy of 100 schizophrenia patients, 37 of their siblings and 200 age-matched healthy controls using a structured written questionnaire. Having been breast-fed was not negatively associated with schizophrenia.

Factors associated with the development of panic attack and panic disorder: Survey in the Japanese population

Abstract  Environmental factors, in addition to genetic factors, may be related to the development of panic attack (PA) and panic disorder (PD). Previous studies suggested that there may be seasonal variation in the onset of PA/PD and possibly a higher prevalence of PA/PD in colder areas. Also observed were lactate‐induced PA and elevated serum cholesterol in PD patients. These suggest that living environment and lifestyle, such as weather conditions, preference of food and physical exercise, might play a role in the occurrence of PA and PD. The present study explored the association of such candidate factors with the development of PA and PD in 4000 Japanese subjects, using a questionnaire. The subjects were recruited from the general population of Japan, using stratified random sampling. Logistic regression with stepwise selection of variables was employed for statistical analysis. Variables including ‘dislike of physical exercise’, mostly in female subjects, and ‘living in areas with longer winter’, in male subjects, were suggested for associations with PA and PD among the candidate factors. The result is preliminary but indicates that lifestyle such as like/dislike of physical exercise and environmental factors including weather conditions could play a partial role in the development of PA and PD. Further investigations are required before firm conclusions can be reached.

Possible association between nonsynonymous polymorphisms of the anaplastic lymphoma kinase (ALK) gene and schizophrenia in a Japanese population

Summary.We examined, for the first time, the possible association between schizophrenia and the anaplastic lymphoma kinase (ALK) gene which plays an important role in neurodevelopment. When two nonsynonymous polymorphisms (Arg1491Lys and Glu1529Asp) were examined, there were significant differences in genotype and allele distributions between patients and controls. Individuals homozygous for the minor allele (1491Lys–1529Asp) were more common in patients than in controls (p = 0.0064, odds ratio 2.4, 95% CI 1.3–4.6). These results suggest that genetic variations of the ALK gene might confer susceptibility to schizophrenia.

Abnormal microstructures of the basal ganglia in schizophrenia revealed by diffusion tensor imaging.

There has been a hypothesis that deficits in the basal ganglia–thalamic system may play an important role in the dysfunctional goal-directed behaviour in schizophrenia. By using diffusion tensor imaging, we measured fractional anisotropy (FA) values in the basal ganglia–thalamic system in 42 schizophrenics and 42 matched controls to investigate microstructural tissue alterations in the basal ganglia–thalamic system in schizophrenia. Schizophrenics had significantly lower FA values in the bilateral globus pallidus and left thalamus compared to controls, suggesting that schizophrenics might have microstructural abnormalities in globus pallidus and thalamus. These data support the notion that myelination abnormalities in basal ganglia–thalamic system are related to the pathophysiology of schizophrenia.

Risk of developing schizophrenia among Japanese high-risk offspring of affected parent: outcome of a twenty-four-year follow up

Aims:  Prospective follow‐up studies of high‐risk children may help clarify the etiological factors in schizophrenia. While studies from North America, Europe and Israel have estimated the risk of schizophrenia at 7–16% in the offspring of an affected parent, no data have been reported for Asian populations.

Changing pattern of mental health utilization in Hachijojima.

Abstract We have reviewed retrospectively 229 patients interviewed by the mental health team in the Hachijojima since the establishment of our services in 1987. The 6 year observation period was classified into three chronological stages for the purposes of identifying any change in the utilization pattern of the mental health services of the island. The rate of schizophrenia was observed to have decreased from 48% in the first 2 years of the study period to 28% in the last 2 years; while that of other mental disorders increased yearly. Interestingly, an increasing number of patients were referred to our services by professionals in areas other than mental health (from 42 to 77%), and patients without any history of psychiatric treatment were more frequently seen (from 36 to 75%) in the later part of the study period. These changes suggest the importance of access to mental health services.

A New Cognitive Therapy for Auditory Hallucinations and Delusions : Development of a Guide for Psychotic Patients and Their Family Members

We have developed a new cognitive therapy for auditory hallucinations and delusions, along with a guide intended to familiarize clients and their families with it. The title of the guide is “A Guide to Coping with Voices of Unknown Origin—10 Items Containing Useful Information on the Treatment of Voices of Unknown Origin.” The guide consists of a preface, 10 chapters, and a postscript, and has the advantages of being easily understandable, quickly readable (in approximately 20 minutes), and full of accurate and useful information to assist clients in coping with psychotic symptoms. Psychiatrists can employ this guide as a teaching aid in psychoeducational therapy sessions for clients and their families. In this chapter, we introduce a portion of the guide, namely Chapters 1, 4, and 10. Next we show the results of a questionnaire administered to clients and their families as an index of the guide’s efficacy.