Graduate School of Medicine  Doctorial Course in Medicine  Public Health and Environmental Medicine  Department of Environmental health science and Public Health

Laboratory Address

1-1-1 Hondo, Akita City

Homepage URL


Mail Address

E-mail address

Research Fields, Keywords

hikikomori (social withdrawal, social isolation), Internet addiction, mental health, community building, suicide prevention

Graduating School 【 display / non-display


    Universiti Putra Malaysia   Faculty of Environmental Studies   Graduated

Graduate School 【 display / non-display

  • 2010.04

    The University of Tokyo  Graduate School, Division of Medicine  Mental Health  Doctor's Course  Completed

  • 2006.09

    The University of Hong Kong  The School of Public Health  Public Health Practice  Master's Course  Completed

Degree 【 display / non-display

  • The University of Hong Kong -  Master in Public Health

Campus Career 【 display / non-display

  • 2016.04

    Akita University   Graduate School of Medicine   Doctorial Course in Medicine   Public Health and Environmental Medicine   The Department of Public Health   Assistant Professor  

  • 2015.07

    Akita University   Graduate School of Medicine   Specially-appointed Assistant Professor  

External Career 【 display / non-display

  • 2013.02

    Health and Global Policy Institute   Researcher  

Academic Society Affiliations 【 display / non-display

  • 2010.04



    Japan Public Health Association

Research Field (grants-in-aid-for-scientific-research classification) 【 display / non-display

  • Medical sociology

  • Community health nursing

  • Community Health

  • Sociology of education


Thesis for a degree 【 display / non-display

  • 日本人集団における3つのインターネット依存症尺度の信頼性と妥当性

    ヨン キム フォン ロザリン 


    Single author

  • Exploring Hikikomori

    Yong Kim Fong Roseline 


    Single author

Published Papers 【 display / non-display

  • Cross-sectional survey of depressive symptoms and suicide-related ideation at a Japanese national university during the COVID-19 stay-home order.

    Nomura K.,Minamizono S.,Maeda E.,Kim R.,Iwata T,Hirayama J,Ono K,Fushimi M.,Goto T.,Mishima K.,Yamamoto F.

    Environ Health Prev Med.   26 ( 1 )   2021.12  [Refereed]

    Domestic Co-author


  • Home visiting support for people with hikikomori (social withdrawal) provided by experienced and effective workers

    Funakoshi A, Saito M, Yong R, Suzuki M.

    International Journal of Social Psychiatry     2021.04  [Refereed]

    Domestic Co-author


  • Characteristics of and gender difference factors of hikikomori among the working-age population: a cross-sectional population study in rural Japan

    Roseline KF Yong, Koji Fujita, Patsy YK CHau, Hisanaga Sasaki

    日本公衆衛生雑誌     2020.04  [Refereed]  [Invited]

    International Co-author


  • Hikikomori is Most Associated with Interpersonal Relationships, Followed by Suicide Risks: A Secondary Analysis of a National Cross-Sectional Study. Frontiers in Psychiatry

    Yong Kim Fong Roseline, Nomura Kyoko

    Frontiers in Psychiatry     2019.04  [Refereed]

    Domestic Co-author

    There have been few population studies of hikikomori (that is, prolonged social withdrawal and isolation), and the basic correlating factors of hikikomori are yet to be identified. Therefore, this study aimed to identify the associated basic characteristics and psychiatric factors of hikikomori. Data were obtained from the Survey of Young People’s Attitudes of 5,000 residents (aged 15–39 years) who were randomly selected from 200 urban and suburban municipalities in Japan in February 2010. The chi-square test and multiple logistic regression were used in the analysis. The data contained 3,262 participants (response rate: 65.4%); 47.7% were men (n = 1,555) and 52.3% were women (n = 1,707). Its prevalence was 1.8% (n = 58), and 41% had been in the hikikomori state for more than 3 years. There were fewer hikikomori people in neighborhoods filled with business and service industries. Significantly more men were in the hikikomori group (65.5%) than in the non-hikikomori group (47.3%). The hikikomori group was more likely to drop out of education (p < .001) and to have a psychiatric treatment history compared with non-hikikomori (37.9% vs 5%, p < .001). The multiple logistic regression analyses revealed that interpersonal relationships were significantly associated with hikikomori across three models (Model 1 adjusting for all basic characteristics, OR = 2.30, 95% CI = 1.92–2.76; Model 2 further adjusting for mental health-related factors, OR = 2.1, 95% CI = 1.64–2.68; Model 3 further adjusting for a previous psychiatric treatment history, OR = 1.95, 95% CI = 1.52–2.51). Additionally, the hikikomori group was more likely to have suicide risk factors (Model 1: OR = 1.85, 95% CI = 1.56–2.20; Model 2: OR = 1.33, 95% CI = 1.05–1.67), obsessive–compulsive behaviors (Model 1: OR = 1.57, 95% CI = 1.20–2.05), and addictive behaviors (Model 1: OR = 1.93, 95% CI = 1.37–2.70). This is the first study to show that hikikomori is associated with interpersonal relationships, followed by suicide risks. Hikikomori people are more likely to be male, have a history of dropping out from education, and have a previous psychiatric treatment history.


  • Caregiver Burden and Work Productivity Among Japanese Working Family Caregivers of People with Dementia

    Fujihara Satoko, Inoue Akiomi, Kubota Kazumi, Yong Kim Fong Roseline, Kondo Katsunori

    International Journal of Behavioral Medicine   26   125 - 135   2018.11  [Refereed]

    Domestic Co-author

    We examined the association between caregiver burden and work productivity (i.e., absenteeism, presenteeism, and overall work impairment) among working family caregivers of people with dementia and whether job characteristics (i.e., job demands, job control, supervisor and coworker support) moderate this association.

    A cross-sectional correlational study design using a web-based questionnaire survey was conducted among 379 Japanese working family caregivers of people with dementia (105 female, age range 20–77) in May 2016, which measured caregiver burden, work productivity, care situation, job characteristics, and demographics. Caregiver burden was designated as an independent variable and each aspect of work productivity as a dependent variable in a hierarchical multiple regression analysis, adjusting for demographics. Interaction terms between caregiver burden and each job characteristic were also included in the model.

    Caregiver burden was significantly and positively associated with presenteeism (β = 0.219, p < 0.001) and overall work impairment (β = 0.181, p < 0.001), while the association of caregiver burden with absenteeism was not significant (β = − 0.003, p = 0.953). Interaction effects of caregiver burden × coworker support on presenteeism (β = − 0.189, p = 0.023) and overall work impairment (β = − 0.172, p = 0.034) were significant. According to simple slope analyses, caregiver burden was greater at lower levels of coworker support compared to higher levels of coworker support for both presenteeism and overall work impairment.

    Our study suggests that higher caregiver burden is associated with a decrease in work productivity. Additionally, coworker support appears to buffer the association of caregiver burden with presenteeism and overall work impairment among working family caregivers of people with dementia.


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Grant-in-Aid for Scientific Research 【 display / non-display

  • Grant-in-Aid for Scientific Research(B)

    Project Year: 2021.04  -  2024.03 

  • Grant-in-Aid for Scientific Research(C)

    Project Year: 2017.04  -  2020.03 

  • Grant-in-Aid for Scientific Research(C)

    Project Year: 2015.04  -  2017.03 

Presentations 【 display / non-display

  • Differences between younger and older hikikomori people.

    Yong R., Fujita K., Sasaki H.

    第22回国際児童青年精神医学とその近接領域学会  2016.09  -  2016.09 

  • Similarities and differences between acute social withdrawal (hikikomori) and Internet addiction.

    Yong R., Funakoshi A

    第22回国際児童青年精神医学とその近接領域学会   2016.09  -  2016.09 

  • Study on the importance of individual level cognitive social capital in suicide prevention among the community-dwelling people.

    Kaneko Y., Fujita J., Yong R., Sasaki H., Eboshida A., Motohashi Y.

    第5回ヨーロッパ精神衛生会議  (Prague)  2016.09  -  2016.09 

  • The relationship between social participation and psychological distress among community-dwelling elderly adults.

    Fujita J., Yong R., Sasaki H., Kaneko Y., Eboshida A.

    第7回国際自殺予防学会アジア・太平洋地域大会  2016.05  -  2016.05 

  • Exploring Hikikomori - Mechanism of Onset and Maintaining Hikikomori

    Yong Kim Fong Roseline, 川上憲人

    第70回日本公衆衛生学会総会  (秋田)  2011.10  -  2011.10  日本公衆衛生学会

    Hikikomori is hard to reach population, making systematic research almost impossible. Limited epidemiology evidence provides very little information of the meaning of withdrawal and isolation behavior. In this paper, we aim to describe the onset and maintenance of hikikomori with a grounded theory approach by aiming to discover concepts and relationships to structure an explanatory theoretical frame of the nature of this experience.

    Methods: Data collection was done over a period of three years, including direct snowball recruitment and online observations. Data analysis and conceptualizing theories were systematically gathered from the raw data, carefully
    avoiding contamination from presumptions, to provide a meaningful insight ofthe phenomenon.
    Results: A sample of 8 participants through snowballing and online observation of an accumulated of 160 people were gathered, and half of the participants from direct recruitment were non Japanese living outside Japan. As we compared and contrasted the data, we discovered that the meaning of hikikomori was not unique to the Japanese population. One overriding theme was revealed, that of hikikomori is a phenomenon of anomic coping, was firmly constructed by two key categories: stasis and expression. Discussion: Stasis is a condition in which there is no action or progress, and an inactivity resulting from a static balance between ill-matches that marked hopelessness, which is very much thought to be of the onset of hikikomori. Expression is a manifestation of how a person could maintain in this living condition, by transferring experience into hindrances where anonymity
    online turn into a transposition of hope for the hikikomori.

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