Kikuchi, Toshiaki

写真a

Affiliation

School of Medicine, Department of Neuropsychiatry ( Shinanomachi )

Position

Associate Professor
Scopus Paper Info  
Paper Count: 86 Citation Count: 1333 h-index: 21

Click to view the Scopus page. The data was downloaded from Scopus API in April 05, 2026, via http://api.elsevier.com and http://www.scopus.com .

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  • 学歴・職歴
    2001年　慶應義塾大学医学部卒業後、同大学医学部精神神経科学教室へ入局
    2002年　社会福祉法人桜ケ丘事業協会　桜ケ丘記念病院、
    2007年　慶應義塾大学医学部研究科博士課程を経て、
    2011年　コロンビア大学精神科　リサーチフェローとして留学
    2013年　帰国後、杏林大学医学部精神神経科学教室　講師、
    2017年　国立研究開発法人日本医療研究開発機構（AMED）脳と心の研究課　主幹
    2018年　慶應義塾大学医学部精神・神経科学教室　助教
    2020年　同　講師
    2024年　同　准教授

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Papers 【 Display / hide 】

  • Dynamic neural network modulation associated with rumination in major depressive disorder: a prospective observational comparative analysis of cognitive behavioral therapy and pharmacotherapy

    Katayama N., Shinagawa K., Hirano J., Kobayashi Y., Nakagawa A., Umeda S., Kamiya K., Tajima M., Amano M., Nogami W., Ihara S., Noda S., Terasawa Y., Kikuchi T., Mimura M., Uchida H.

    Translational Psychiatry 15 ( 1 )  2025.12

    　View Summary

    Cognitive behavioral therapy (CBT) and pharmacotherapy are primary treatments for major depressive disorder (MDD). However, their differential effects on the neural networks associated with rumination, or repetitive negative thinking, remain poorly understood. This study included 135 participants, whose rumination severity was measured using the rumination response scale (RRS) and whose resting brain activity was measured using functional magnetic resonance imaging (fMRI) at baseline and after 16 weeks. MDD patients received either standard CBT based on Beck’s manual (n = 28) or pharmacotherapy (n = 32). Using a hidden Markov model, we observed that MDD patients exhibited increased activity in the default mode network (DMN) and decreased occupancies in the sensorimotor and central executive networks (CEN). The DMN occurrence rate correlated positively with rumination severity. CBT, while not specifically designed to target rumination, reduced DMN occurrence rate and facilitated transitions toward a CEN-dominant brain state as part of broader therapeutic effects. Pharmacotherapy shifted DMN activity to the posterior region of the brain. These findings suggest that CBT and pharmacotherapy modulate brain network dynamics related to rumination through distinct therapeutic pathways.

  • Long-term effectiveness of vortioxetine on achievement of personal goals and work productivity in patients with major depressive disorder: The VGOAL-J study

    Watanabe K., Sumiyoshi T., Kato M., Kikuchi T., Moriguchi Y., Åström D.O., Christensen M.C.

    Journal of Affective Disorders Reports 21 2025.07

    　View Summary

    Background: The long-term effectiveness of vortioxetine for facilitating progress toward personal recovery goals and improving productivity at work was assessed in patients with major depressive disorder (MDD). Methods: Single-arm, prospective, 24-week cohort study in employed patients with MDD initiating treatment with vortioxetine (n = 121) in outpatient settings in Japan. The Goal Attainment Scale for Depression (GAS-D) was used to evaluate progress toward personal recovery goals. At baseline, a combination of patient-defined and pre-specified goals was established collaboratively with the treating psychiatrist, followed by longitudinal assessments at baseline and weeks 4, 8, 12, and 24. Work-related productivity was assessed using the Work Productivity and Activity Impairment (WPAI) questionnaire. Co-primary endpoints were the proportion of patients achieving their pre-specified personal recovery goals at week 12 and the change in work productivity from baseline. Results: In all, 45/107 patients (42.1%) had achieved their personal recovery goals at week 12, increasing to 62/100 (62.0%) at week 24. Significant improvement was observed across all WPAI domains (i.e., absenteeism, presenteeism, productivity loss, and activity impairment) at week 24. Depressive symptoms, global patient functioning, emotional and cognitive symptoms, cognitive performance, and quality of life also significantly improved over the 24 weeks of follow-up. At week 24, 80/102 patients (78.4%) remained on vortioxetine; 49 of these patients (61.3%) were receiving vortioxetine 20 mg/day. Limitations: Open-label study. Conclusions: Vortioxetine was found to be effective in helping to achieve personal recovery goals and in enhancing workplace productivity over the 6-month study period in patients with MDD. Trial registration: Japan Primary Registries Network: JRCT1031210200.

  • Impact of Emotional Blunting on Patient Social Function and Depressive Symptoms: A Post Hoc Analysis of a Web-Based Survey in Japanese Patients with Major Depressive Disorder

    Kikuchi T., Iga J.I., Hattori A., Tokuda F., Moriguchi Y., Hoshino T.

    Neuropsychiatric Disease and Treatment 21   841 - 854 2025

    　View Summary

    Background: Emotional blunting (EB), defined as a flattening of emotions and emotional indifference, is reported by many patients with major depressive disorder (MDD) taking antidepressants. Severity of EB correlates with depressive symptoms, as well as deficits in social function, anxiety and health-related quality of life. However, awareness and understanding of EB and its impact on treatment of MDD remain poorly understood. Methods: This was a post hoc analysis of data from a web-based survey of 3376 adults with MDD in Japan. The primary endpoint was the correlation between total and subdomain scores of the Oxford Depression Questionnaire (ODQ; a validated instrument to assess EB) and total and individual domain/item scores of the Work and Social Adjustment Scale (WSAS) and Patient Health Questionnaire 9-item (PHQ-9). The secondary endpoint explored which patients had a discrepancy between EB symptoms (assessed by the ODQ) and their own evaluation of EB (using a validated screening question). Results: There was a moderate correlation between the ODQ total score and the WSAS total score (Spearman’s rank correlation coefficient [r<inf>s</inf> ] = 0.578) and a strong correlation between the ODQ total score and PHQ-9 total score (r<inf>s</inf> = 0.670). Multiple regression analyses showed that the ODQ subdomains “not caring” (NC) and “reduction in positive emotions” (PR) had the greatest impact on both the WSAS total score (partial regression coefficients = 1.034 and 0.501, respectively) and PHQ-9 total score (partial regression coefficients = 0.548 and 0.592, respectively). A higher proportion of men (versus women) and unemployed individuals (versus employed individuals) underestimated their EB severity compared with their ODQ score. Conclusion: The ODQ subdomains of NC and PR are important factors when evaluating the impact of EB on social function and severity of depressive symptoms in patients with MDD. Physicians should assess EB symptoms for each patient, considering the patient’s background.

  • Network meta-analysis of the effectiveness of psychotherapies with or without medication for treating adult depression

    Fukumori M., Kikuchi T., Zhou Y., Hattori S., Kudo T.

    Acta Neuropsychiatrica 36 ( 6 ) 423 - 437 2024.12

    ISSN  09242708

    　View Summary

    Objective: To ascertain whether psychotherapies combined with medication are more efficacious than those without medication and determine which combinations yield the best results. Methods: We conducted a network meta-analysis of randomised controlled trials (RCTs) comparing behavioural activation (BA), psychoanalytic/psychodynamic psychotherapy (DYN), interpersonal psychotherapy (IPT), individual face-to-face cognitive behavioural therapy (CBT (ftf)), group cognitive behavioural therapy (gCBT), and computerised or internet cognitive behavioural therapy (iCBT) with each other, or with treatment-as-usual (TAU) and wait list control (WLC) among adults formally diagnosed with depression. The psychotherapy arms were categorised as either psychotherapy alone or psychotherapy combined with medication (+ p). Treatment efficacy was assessed based on depression severity. We used a random-effects model to conduct a pairwise meta-analysis. Results: A total of 100 RCTs with 9,873 participants were included. The most common treatment was CBT (ftf) alone. All treatment arms were compared with TAU. Most psychotherapies combined with medication were superior to psychotherapy alone. In the subgroup analyses according to the baseline severity of depression, most psychotherapies combined with medication were more effective than psychotherapy alone in moderate-to-severe depression, whereas in mild depression, such differences were not observed. Among psychotherapies with medication, gCBT + p was significantly more effective than TAU and other psychotherapies in both the main and subgroup analyses. Conclusion: The efficacy of depression treatment varied depending on the severity of the depressive condition. Notably, gCBT + p was identified as the most effective approach for treating adult depression.

  • Gender differences and mental distress during COVID-19: a cross-sectional study in Japan

    Kanata T., Takeda K., Fujii T., Iwata R., Hiyoshi F., Iijima Y., Nakao T., Murayama K., Watanabe K., Kikuchi T., Mimura M., Yoshimi A., Hishimoto A., Hirata H., Ozaki N., Kito S., Kuga H., Oba M., Oi H., Nakagome K.

    BMC Psychiatry 24 ( 1 )  2024.12

    　View Summary

    Background: To identify risk factors for mental distress and investigate whether the factors were different between men and women during the coronavirus disease 2019 (COVID-19), using KOKOROBO data, which is an online platform that aims to facilitate access to mental health services. Methods: We used baseline data on KOKOROBO users 13 years of age or older in Japan who accessed it from October 11, 2021, to April 6, 2023, excluding those receiving treatment for mental health problems. Global severity, based on the most severe measure on Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Insomnia Severity Index (ISI), was analyzed using multivariable logistic regression with baseline characteristics for each gender, and for under 30 and 30 years of age or older in women. We conducted the same analysis of suicidal ideation for each gender. Results: In the 686 men and 1274 women, 117 (17.1%) and 100 (7.8%) had minimal global severity respectively, and the rest suffered from mental distress to some extent. For women, ages under 30 years (adjusted OR (aOR): 0.352, 95%CI: 0.231–0.539, P < 0.001), marriage (aOR: 0.453, 95%CI: 0.274–0.746, P = 0.002), and concerns about COVID-19 infection were associated with global severity, while having children (aOR: 0.509, 95% CI: 0.284–0.909, P = 0.023) and decrease of going out during the COVID-19 pandemic had a protective effect on global severity and suicidal ideation for men, respectively. Living with family was a risk factor for mental distress in unmarried women over 30 years of age. Less communication with family or others and responding to the questionnaire late at night (00:00–05:59) were associated with severe global severity in both genders. Conclusions: Age, living arrangement, marriage, having children, concerns about COVID-19 infection, and lifestyle changes during the COVID-19 pandemic had gender-specific effects on mental distress, while frequent communication and regular life rhythm maintained mental health in both genders. Young women and, unmarried middle-aged women living with their families tended to experience mental distress during the COVID-19 pandemic. Trial registration: The Ethics Committee of the National Center of Neurology and Psychiatry approved this study (approval number B2020141) on April 15, 2021.

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Reviews, Commentaries, etc. 【 Display / hide 】

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Presentations 【 Display / hide 】

  • 初発分裂病のDUP(未治療期間）と治療コンプライアンスに関する検討

    Kobayashi Hiroyuki, Suzuki Yukiko, Yokoyama Tomoko, Tsukahara Mihoko, Kikuchi Toshiaki, Yamazawa Ryouko, Mizuno Masafumi, Yagi Gouhei, Kashima Haruo

    [Domestic presentation]  東京精神医学会第66回学術集会, 

    2002.11
    , 

    Oral presentation (general)

  • 非定型抗精神病薬の普及度と適応に関する研究

    Tomita Masayuki, Watanabe Kouichirou, Kikuchi Toshiaki, Takeuchi Hiroyoshi, Kishimoto Taishirou, Nomura Kensuke, Nakagawa Atsuo, Yamazawa Ryouko, Uchida Hiroyuki, Suzuki Takefumi, Nozaki Shouko, Tomita Atsuko, Takano Harumasa, Inagaki Ataru, Yagi Gouhei

    [Domestic presentation]  第12回日本臨床精神神経薬理学会, 

    2002.10
    , 

    Poster presentation

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

  • An fMRI study to explore neural activity of praecox feeling

    2018.04
    -
    2021.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Early-Career Scientists , Principal investigator

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Courses Taught 【 Display / hide 】

  • MEDICAL PROFESSIONALISM 6

    2025

  • LECTURE SERIES, PSYCHIATRY

    2025

  • ISSUES IN PSYCHOPATHOLOGY

    2025

  • CLINICAL CLERKSHIP IN PSYCHIATRY

    2025

  • BEHAVIORAL SCIENCE 2

    2025

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