Mimura, Masaru



School of Medicine, Department of Neuropsychiatry (Shinanomachi)




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  • Increased blood COASY DNA methylation levels a potential biomarker for early pathology of Alzheimer’s disease

    Kobayashi N., Shinagawa S., Niimura H., Kida H., Nagata T., Tagai K., Shimada K., Oka N., Shikimoto R., Noda Y., Nakajima S., Mimura M., Shigeta M., Kondo K.

    Scientific Reports (Scientific Reports)  10 ( 1 )  2020.12

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    © 2020, The Author(s). Early diagnosis of dementia including Alzheimer’s disease (AD) is an urgent medical and welfare issue. However, to date, no simple biometrics have been available. We reported that blood DNA methylation levels of the COASY gene, which encodes coenzyme A synthase, were increased in individuals with AD and amnestic mild cognitive impairment (aMCI). The present study sought to replicate these findings with larger numbers of samples. Another objective was to clarify whether COASY methylation is associated with neurodegeneration through a comparison of AD, AD with cardiovascular disease (CVD), and vascular dementia (VaD). We measured blood COASY methylation levels in normal controls (NCs) (n = 200), and individuals with aMCI (n = 22), AD (n = 151), and VaD (n = 21). Compared with NCs, they were significantly higher in individuals with aMCI and AD. Further, they were significantly higher in AD patients without cardiovascular diseases compared to AD patients with them. These findings suggest that COASY methylation levels may be related to neurodegeneration in AD.

  • Study design and baseline characteristics of a population-based prospective cohort study of dementia in Japan: the Japan Prospective Studies Collaboration for Aging and Dementia (JPSC-AD)

    Ninomiya T., Nakaji S., Maeda T., Yamada M., Mimura M., Nakashima K., Mori T., Takebayashi M., Ohara T., Hata J., Kokubo Y., Uchida K., Taki Y., Kumagai S., Yonemoto K., Yoshida H., Muto K., Momozawa Y., Akiyama M., Kubo M., Ikeda M., Kanba S., Kiyohara Y., Ninomiya T., Shibata M., Yoshida D., Hirakawa Y., Honda T., Chen S., Hirabayashi N., Furuta Y., Mihara A., Nakazawa T., Ohara T., Ihara K., Murashita K., Sawada K., Jung S., Terayama Y., Yonezawa H., Takahashi J., Akasaka H., Noguchi-Shinohara M., Iwasa K., Sakai K., Hayashi K., Niimura H., Shikimoto R., Kida H., Eguchi Y., Fukada Y., Kowa H., Wada K., Kishi M., Yoshida T., Shimizu H., Tachibana A., Ueno S.i., Ishikawa T., Fukuhara R., Koyama A., Hashimoto M., Esaki M., Takano Y., Inoue Y.

    Environmental Health and Preventive Medicine (Environmental Health and Preventive Medicine)  25 ( 1 )  2020.12

    ISSN  1342078X

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    © 2020, The Author(s). Background: The burden of dementia is growing rapidly and has become a medical and social problem in Japan. Prospective cohort studies have been considered an effective methodology to clarify the risk factors and the etiology of dementia. We aimed to perform a large-scale dementia cohort study to elucidate environmental and genetic risk factors for dementia, as well as their interaction. Methods: The Japan Prospective Studies Collaboration for Aging and Dementia (JPSC-AD) is a multisite, population-based prospective cohort study of dementia, which was designed to enroll approximately 10,000 community-dwelling residents aged 65 years or older from 8 sites in Japan and to follow them up prospectively for at least 5 years. Baseline exposure data, including lifestyles, medical information, diets, physical activities, blood pressure, cognitive function, blood test, brain magnetic resonance imaging (MRI), and DNA samples, were collected with a pre-specified protocol and standardized measurement methods. The primary outcome was the development of dementia and its subtypes. The diagnosis of dementia was adjudicated by an endpoint adjudication committee using standard criteria and clinical information according to the Diagnostic and Statistical Manual of Mental Disorders, 3rd Revised Edition. For brain MRI, three-dimensional acquisition of T1-weighted images was performed. Individual participant data were pooled for data analyses. Results: The baseline survey was conducted from 2016 to 2018. The follow-up surveys are ongoing. A total of 11,410 individuals aged 65 years or older participated in the study. The mean age was 74.4 years, and 41.9% were male. The prevalence of dementia at baseline was 8.5% in overall participants. However, it was 16.4% among three sites where additional home visit and/or nursing home visit surveys were performed. Approximately two-thirds of dementia cases at baseline were Alzheimer’s disease. Conclusions: The prospective cohort data from the JPSC-AD will provide valuable insights regarding the risk factors and etiology of dementia as well as for the development of predictive models and diagnostic markers for the future onset of dementia. The findings of this study will improve our understanding of dementia and provide helpful information to establish effective preventive strategies for dementia in Japan.

  • Primary functional brain connections associated with melancholic major depressive disorder and modulation by antidepressants

    Ichikawa N., Lisi G., Yahata N., Okada G., Takamura M., Hashimoto R.i., Yamada T., Yamada M., Suhara T., Moriguchi S., Mimura M., Yoshihara Y., Takahashi H., Kasai K., Kato N., Yamawaki S., Seymour B., Kawato M., Morimoto J., Okamoto Y.

    Scientific Reports (Scientific Reports)  10 ( 1 )  2020.12

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    © 2020, The Author(s). The limited efficacy of available antidepressant therapies may be due to how they affect the underlying brain network. The purpose of this study was to develop a melancholic MDD biomarker to identify critically important functional connections (FCs), and explore their association to treatments. Resting state fMRI data of 130 individuals (65 melancholic major depressive disorder (MDD) patients, 65 healthy controls) were included to build a melancholic MDD classifier, and 10 FCs were selected by our sparse machine learning algorithm. This biomarker generalized to a drug-free independent cohort of melancholic MDD, and did not generalize to other MDD subtypes or other psychiatric disorders. Moreover, we found that antidepressants had a heterogeneous effect on the identified FCs of 25 melancholic MDDs. In particular, it did impact the FC between left dorsolateral prefrontal cortex (DLPFC)/inferior frontal gyrus (IFG) and posterior cingulate cortex (PCC)/precuneus, ranked as the second ‘most important’ FC based on the biomarker weights, whilst other eight FCs were normalized. Given that left DLPFC has been proposed as an explicit target of depression treatments, this suggest that the limited efficacy of antidepressants might be compensated by combining therapies with targeted treatment as an optimized approach in the future.

  • Optimal robot for intervention for individuals with autism spectrum disorders

    Kumazaki H., Muramatsu T., Yoshikawa Y., Matsumoto Y., Ishiguro H., Kikuchi M., Sumiyoshi T., Mimura M.

    Psychiatry and Clinical Neurosciences (Psychiatry and Clinical Neurosciences)  74 ( 11 ) 581 - 586 2020.11

    ISSN  13231316

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    © 2020 The Authors. Psychiatry and Clinical Neurosciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Psychiatry and Neurology With recent rapid advances in technology, human-like robots have begun functioning in a variety of ways. As increasing anecdotal evidence suggests, robots may offer many unique opportunities for helping individuals with autism spectrum disorders (ASD). Individuals with ASD often achieve a higher degree of task engagement through the interaction with robots than through interactions with human trainees. The type and form of robots to be used for individuals with ASD have been meticulously considered. Simple robots and animal robots are acceptable because of their simplicity and the ease of interesting and engaging interactions. Android robots have the benefit of the potential of generalization into daily life to some extent. Considering the affinity between robots and users is important to draw out the potential capabilities of robotic intervention to the fullest extent. In the robotic condition, factors such as the appearance, biological motion, clothes, hairstyle, and disposition are important. Many factors of a user, such as age, sex, and IQ, may also affect the affinity of individuals with ASD toward a robot. The potential end-users of this technology may be unaware or unconvinced of the potential roles of robots in ASD interventions. If trainers have extensive experience in using robots, they can identify many potential roles of robots based on their experience. To date, only a few studies have been conducted in the field of robotics for providing assistance to individuals with ASD, and future studies are needed to realize an optimal robot for this purpose.

  • Lower mortality from suicidal trauma among patients with a psychiatric diagnosis upon admission: Nationwide japanese retrospective cohort study

    Ishida T., Kuwahara Y., Shibahashi K., Okura Y., Sugiyama K., Hamabe Y., Mimura M., Suzuki T., Uchida H.

    Psychiatry Research (Psychiatry Research)  293 2020.11

    ISSN  01651781

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    © 2020 Suicide and self-harm are major public health issues. Few studies have compared mortality from suicidal trauma between patients with and without contact with psychiatric services. This study aimed to compare the in-hospital mortality of suicidal trauma between patients with and without a psychiatric diagnosis upon hospital admission. Data on 15- to 90-year-old patients with suicidal trauma between 2004 and 2015 was extracted from the Japan Trauma Data Bank. In-hospital mortality were compared between patients with and without a psychiatric diagnosis. A total of 9,803 patients were included. The median age was 42 years (interquartile range: 29–59), and 5,010 patients (51.1%) were male. The most frequent method of injury was falling from a height (53.4%), followed by stabbing (32.3%) and burns (6.2%). In total, 4,878 patients (49.8%) had a psychiatric diagnosis upon admission. The proportion of patients with a psychiatric diagnosis was significantly lower among males, teenagers, and older people. In-hospital mortality was significantly lower among patients with a psychiatric diagnosis than those without (10.9%vs18.7%). Contact with psychiatric services might be protective among people with suicidal trauma. However, the proportion of psychiatric service use was generally low. These findings show the importance of delivering appropriate psychiatric services to high-risk patients.

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • Visual Cognitive Bhavioral Therapy(V-CBT) for Higher Brain Dysfunction.


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 三村 將, Grant-in-Aid for Scientific Research (C), Principal Investigator

  • Analyses of unsafe driving behaviors of elderly drivers by using drive recorders and brain images


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 三村 将, Grant-in-Aid for Scientific Research (C), Principal Investigator

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    Unsafe behaviors during actual automobile driving of elderly drivers including mild cognitive impairment and higher brain dysfunction were examined using objective evaluation by the driving instructor, drive recorder evaluation by the occupational therapist, and subjective evaluation pre- and post-actual driving by the participants themselves. Significant correlations were observed between the driving instructor's evaluation for actual driving and occupational therapist's evaluation for drive recorder images. The results also demonstrated that those whose driving instructor's evaluation scores were low tended to show high self-evaluation prior to the actual driving test, Pre-test high self-evaluation decreased in the post-test evaluation. The present study suggest that self-evaluation for driving behavior is significantly contributing to the safe and appropriate driving behaviors in the elderly drivers.


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