研究者業績

Nakao Iwata

  (岩田 仲生)

Profile Information

Affiliation
School of Medicine, Fujita Health University
Degree
博士(医学)(名古屋大学)

J-GLOBAL ID
200901048638344557
researchmap Member ID
5000024641

External link

Education:
1993 Ph.D. (Dr of Medical Science) Nagoya University The Graduate School of Medicine
(Prof. Toshiharu Nagatsu)
1989 M.D. Nagoya University School of Medicine
Professional training:
2017-present Vice president, Fujita Health University
2015-present Dean of the School of Medicine, Fujita Health University
2003-present Professor, Dep. Psychiatry, Fujita Health University School of Medicine
2002-2003 Assoc. Prof. Dep. Psychiatry, Fujita Health University School of Medicine
1998-2002 Assit. Prof. Dep. Psychiatry, Fujita Health University School of Medicine
(Prof. Norio Ozaki)
1996-1998 Visiting Fellow, Lab. Neurogenetics, NIAAA/NIH
(Dr. David Goldman)
1994-1996 Medical Staff, Dep. Psychiatry, Nagoya University School of Medicine
(Prof. Tatsuro Ohta)
1993-1994 Clinical Fellow in Medicine, North Hospital, Nagoya
1989-1990 Resident in Medicine, Kyoritsu General Hospital, Nagoya



Research field
Psychiatric genetics, Pharmacogenetics, Clinical psychopharmacology

NAKAO IWATA, M.D., Ph.D. is Professor of Psychiatry Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, JAPAN. He attended medical school and graduate school at Nagoya University and majored molecular neurochemistry and clinical psychiatry. He has published on many topics, including psychiatric genetics, pharmacogenomics, and clinical neuropsychopharmacology.

Research Areas

 1

Papers

 627
  • Takuma Ashizawa, Takeo Saito, Tomo Okochi, Kohei Ninomiya, Kenta Ito, Rei Aoki, Masashi Ikeda, Nakao Iwata
    Translational Psychiatry, 14(1), Oct 14, 2024  
    Abstract Recent genome-wide association studies (GWASs) have identified fatty acid desaturase (FADS) genes, which code key enzymes involved in polyunsaturated fatty acid (PUFA) desaturation as susceptibility genes for bipolar disorder (BD). Several quantitative changes in PUFAs suggest their involvement in BD pathogenesis. Therefore, this study aimed to clarify the relationship between BD and PUFAs by conducting lipidomics covariating with the FADS gene variant (rs174550), which is associated with PUFA levels and BD susceptibility. The concentrations of 23 fatty acids were measured using plasma samples from the BD group (n = 535) and the control group (n = 107). Differences in each PUFA concentration ratio were compared between the two groups. Also, differences in each PUFA concentration ratio were compared for each genotype in rs174550. Our results showed that the BD group had significantly lower concentrations of linoleic acid (LA) (β = −0.36, p = 0.023) and arachidonic acid (AA) (β = −0.18, p = 0.013) than the control group. Concerning the effect of FADS on the PUFA concentration ratio, carriers of C-allele at rs174550 had significantly decreased γ-linolenic acid and AA concentration ratios. A previous GWAS reported that the presence of a C-allele at rs174550 increased the BD risk. This direction is consistent with the lipidomic results of the present study. In conclusion, both the FADS and BD were considered to regulate the AA concentration. Thus, as the FADS gene variant is crucial for conducting lipidomics of BD we believe that the allele frequency of FADS must be analyzed.
  • Taro Kishi, Toshikazu Ikuta, Kenji Sakuma, Shun Hamanaka, Yasufumi Nishii, Masakazu Hatano, Shinsuke Kito, Nakao Iwata
    JAMA network open, 7(10) e2441159, Oct 1, 2024  
    IMPORTANCE: To date, several theta burst stimulation (TBS) protocols, such as intermittent TBS (iTBS), have been proposed; however, previous systematic reviews have revealed inconsistent efficacy findings in individual TBS studies for schizophrenia. OBJECTIVE: To examine which TBS protocols are associated with the most favorable and acceptable outcomes in adults with schizophrenia. DATA SOURCES: The Cochrane Library, PubMed, and Embase databases were searched for studies published before May 22, 2024. STUDY SELECTION: The inclusion criteria were as follows: (1) published and unpublished randomized clinical trials (RCTs) of any TBS treatment and (2) RCTs including individuals with schizophrenia spectrum disorders, other psychotic disorders, or both. DATA EXTRACTION AND SYNTHESIS: This study followed the Cochrane standards for data extraction and data quality assessment and used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline for reporting. The risk of bias of individual studies was assessed using the second version of the Cochrane risk of bias tool, and the Confidence in Network Meta-Analysis application was used to rate the certainty of evidence for meta-analysis results. At least 2 authors double-checked the literature search, data transfer accuracy, and calculations. MAIN OUTCOMES AND MEASURES: The primary outcome of this study was improvement in scores related to negative symptoms. Our frequentist network meta-analysis used a random-effects model. The standardized mean difference (SMD) or odds ratio for continuous or dichotomous variables, respectively, was calculated with 95% CIs. RESULTS: A total of 30 RCTs of 9 TBS protocols, with 1424 participants, were included. Only iTBS over the left dorsolateral prefrontal cortex (L-DLPFC) was associated with reduced negative symptom scores (SMD, -0.89; 95% CI, -1.24 to -0.55), overall symptom scores (SMD, -0.81; 95% CI, -1.15 to -0.48), Positive and Negative Syndrome Scale general subscale scores (SMD, -0.57; 95% CI, -0.89 to -0.25), depressive symptom scores (SMD, -0.70; 95% CI, -1.04 to -0.37), and anxiety symptom scores (SMD, -0.58; 95% CI, -0.92 to -0.24) and improved overall cognitive impairment scores (SMD, -0.52; 95% CI, -0.89 to -0.15) compared with a sham. However, positive symptom score changes, all-cause discontinuation rate, discontinuation rate due to adverse events, headache incidence, and dizziness incidence did not significantly differ between any TBS protocols and sham. CONCLUSIONS AND RELEVANCE: In this network meta-analysis, iTBS over the L-DLPFC was associated with improved scores for negative, depressive, anxiety, and cognitive symptoms in individuals with schizophrenia and was well tolerated by the participants. Other forms of TBS were not associated with benefit. Further research is needed to assess the potential role of TBS in the treatment of schizophrenia.
  • Jun Ishigooka, Kazuyuki Nakagome, Tetsuro Ohmori, Nakao Iwata, Ken Inada, Jun-Ichi Iga, Taro Kishi, Kiyoshi Fujita, Yuka Kikuchi, Toshiaki Shichijo, Hideaki Tabuse, Shotatsu Koretsune, Hiroshi Terada, Haruko Terada, Toshifumi Kishimoto, Yuichiro Tsutsumi, Kazutaka Ohi
    BMC psychiatry, 24(1) 600-600, Sep 5, 2024  
    BACKGROUND: We report the final results of treatment with aripiprazole, blonanserin, and paliperidone from the Japan Useful Medication Program for Schizophrenia (JUMPs), a 104-week naturalistic study. METHODS: JUMPs was an open-label, three-arm, randomized, parallel-group, 104-week study. Patients aged ≥ 20 years with schizophrenia requiring antipsychotic treatment or a switch from previous therapy were enrolled. The primary endpoint was treatment discontinuation rate over 104 weeks. Secondary endpoints included remission rate, Personal and Social Performance (PSP), safety, Positive and Negative Syndrome Scale (PANSS), and quality of life (QOL; EuroQol-5 dimension). RESULTS: In total, 251 patients received aripiprazole (n = 82), blonanserin (n = 85), or paliperidone (n = 84). Treatment discontinuation rates (aripiprazole, 80.5%; blonanserin, 81.2%; paliperidone, 71.4%) were not significantly different (p = 0.2385) among the treatment groups at 104 weeks; comparable outcomes were observed for endpoints, including remission (42.9%, 46.7%, and 45.8%), PANSS, and safety. In the overall cohort, while the improvement in the PSP total score at Week 104 was not significantly different from baseline, a significant improvement (p < 0.05) in QOL and total PANSS scores (including all subscales) was observed at Week 104 compared with baseline. Multivariable analysis identified a shorter disease duration and a higher chlorpromazine-equivalent antipsychotic dosage level (≥ 1000 mg) before switching to monotherapy as predictors of treatment discontinuation. CONCLUSIONS: The 104-week treatment outcomes were comparable between groups; the overall trend of improvement in remission rate, safety, and QOL suggests the importance of continued treatment. CLINICAL TRIAL REGISTRATION: UMIN-Clinical Trials Registry UMIN000007942 (public release date: 14/05/2012).
  • Kazuki Okumura, Tsutomu Takeda, Takashi Komori, Michihiro Toritsuka, Kazuhiko Yamamuro, Ryohei Takada, Minobu Ikehara, Kohei Kamikawa, Yuki Noriyama, Yuki Nishi, Rio Ishida, Yoshinori Kayashima, Takahira Yamauchi, Nakao Iwata, Manabu Makinodan
    Psychiatry and clinical neurosciences, Jul 22, 2024  
    AIM: Adverse childhood experiences are potentially traumatic events with long-lasting effects on the health and well-being of patients with autism spectrum disorder (ASD). It is important to clarify which types of long-lasting autism-related symptoms are influenced by childhood experiences to design future intervention studies. However, few studies have examined the association between childhood experiences and autistic symptoms in large samples of adults with ASD and individuals with typical development (TD). In this study, we evaluate the effects of adverse childhood experiences on multiple ASD phenotypes among both individuals with ASD and those with TD. METHOD: We combined questionnaire evaluations; Childhood Abuse and Trauma Scale, the Japanese version of the Autism-Spectrum Quotient, Conners' Adult ADHD Rating Scale, the Japanese version of the Impact of Event Scale-Revised, and the Japanese version of the Adolescent/Adult Sensory Profile. RESULTS: Individuals with ASD and those with TD (n = 205 and 104, respectively) were included. There were significant correlations between the extent of adverse childhood experiences and severity of attention-deficit/hyperactivity disorder symptoms, posttraumatic stress disorder symptoms, and hypersensitivity in both participants with ASD and those with TD. By contrast, ASD core symptoms showed no significant correlation with adverse childhood experiences in either group. These results remained consistent after adjusting for age, sex, and the estimated intelligence quotient. CONCLUSION: These findings suggest the need for a detailed disentanglement of ASD-related core and peripheral symptoms of adverse childhood experiences, which may help to appropriately set outcomes for future early interventions for the childhood experiences of individuals with ASD.
  • Taro Kishi, Toshikazu Ikuta, Kenji Sakuma, Masakazu Hatano, Yuki Matsuda, Jonas Wilkening, Roberto Goya-Maldonado, Martin Tik, Nolan R Williams, Shinsuke Kito, Nakao Iwata
    Molecular psychiatry, Jun 6, 2024  
    In clinical practice, theta burst stimulation (TBS) presents as a more efficient and potentially more effective therapeutic modality than conventional repetitive transcranial magnetic stimulation (rTMS), as it allows for the delivery of more stimuli in less time and at similar intensities. To date, accelerated treatment plans according to various continuous (cTBS) and intermittent TBS (iTBS) protocols for depression have been proposed. To investigate which of the TBS protocols provided a favorable risk-benefit balance for individuals with depression, this systematic review and random-effects model network meta-analysis was conducted. The study outcomes included response rate (primary), depression symptom improvement, remission rate, all-cause discontinuation rate, incidence of switch to mania, and incidence of headache/discomfort at treatment site. In this meta-analysis, a total of 23 randomized controlled trials (n = 960, mean age = 41.88 years, with 60.78% females) were included. Approximately 69.57% of the trials included individuals with an exclusive diagnosis of major depressive disorder. The following six TBS protocols (target) were evaluated: cTBS (right-dorsolateral prefrontal cortex [R-DLPFC]), cTBS (R-DLPFC) + iTBS (left-DLPFC [L-DLPFC]), iTBS (L-DLPFC), iTBS (L-DLPFC) + iTBS (R-DLPFC), iTBS (left-dorsomedial prefrontal cortex) + iTBS (right-dorsomedial prefrontal cortex), and iTBS (occipital lobe). Compared to sham, cTBS (R-DLPFC) + iTBS (L-DLPFC), iTBS (L-DLPFC), and iTBS (occipital lobe) had a higher response rate (k = 23); cTBS (R-DLPFC) + iTBS (L-DLPFC) and iTBS (L-DLPFC) dominated in the depression symptom improvement (k = 23); and iTBS (L-DLPFC) had a higher remission rate (k = 15). No significant differences were found for all-cause discontinuation rate (k = 17), incidence of switch to mania (k = 7), and incidence of headache/discomfort at treatment site (k = 10) between any TBS protocols and sham. Thus, cTBS (R-DLPFC) + iTBS (L-DLPFC) and iTBS (L-DLPFC) demonstrate favorable risk-benefit balance for the treatment of depression.

Misc.

 634

Books and Other Publications

 6

Research Projects

 15