Open access Original research BMJ Open: first published as 10.1136/bmjopen-2019-029988 on 3 November 2019. Downloaded from Mental well- being of international migrants to Japan: a systematic review Russell Miller, Yuri Tomita, Ken Ing Cherng Ong, Akira Shibanuma , Masamine Jimba To cite: Miller R, Tomita Y, ABSTRACT Strengths and limitations of this study Ong KIC, et al. Mental Background Migration is a stressful process of well- being of international resettlement and acculturation that can often negatively ► Our study is the first to comprehensively screen and migrants to Japan: a impact the mental health of migrants. International systematic review. BMJ Open synthesise available research, published both in migration to Japan, a country with dominant ethnic 2019;9:e029988. doi:10.1136/ Japanese and English, on the mental well- being of homogeneity, is growing steadily amid an ageing domestic bmjopen-2019-029988 international migrants to Japan. population and severe labour shortages. ► Key findings were extracted and thematically anal- ► Prepublication history and Objectives To identify the contemporary barriers to, ysed from relevant studies of diverse migrant popu- additional material for this and facilitators of, mental well- being among the migrant lations in Japan evidencing the role of social support paper are available online. To population in Japan. view these files, please visit networks. Design Systematic review the journal online (http:// dx. doi. ► The cross-sectional nature of the included studies Data sources PubMed, ProQuest, Web of Science, Ichushi org/ 10. 1136/ bmjopen- 2019- limits their value in terms of generalisability and and J- Stage 029988). supporting causal effects. Eligibility criteria Research articles examining the mental ► While English and Japanese databases were sur- Received 21 February 2019 well-being of international migrants in Japan that were veyed, grey literature was not comprehensively Revised 09 October 2019 published in English or Japanese between January 2000 searched. Accepted 09 October 2019 and September 2018 were included. Data extraction and synthesis Full texts of relevant articles were screened and references of the included permanently in a country where he or she was studies were hand-searched for further admissible articles. not born, and has acquired some significant Study characteristics, mental well-being facilitators 2 and barriers, as well as policy recommendations were social ties to [their] new location’. There- synthesised into categorical observations and were then fore migrants include non-indigenous people thematically analysed. who are long-term immigrants, organisa- http://bmjopen.bmj.com/ Results Fifty-five studies (23 published in English), tional expatriates, international students and surveying a total of 8649 migrants, were identified. migrant workers as well as forced migrants The most commonly studied migrant nationalities were such as asylum seekers and refugees. While Brazilian (36%), followed by Chinese (27%) and Filipino motivated by push and pull factors based on (8%). Thematic analysis of barriers to mental well- being perceptions of opportunity, international among migrants chiefly identified‘language difficulties’, migration has been well documented to be a ‘being female’ and ‘lack of social support’, whereas the stressful and multi- factorial process that can primary facilitators were ‘social networks’ followed by 2–4 adversely affect health. The ‘right to health’ on September 26, 2021 by guest. Protected copyright. ‘cultural identity’. Policy recommendations for authorities generally described more migrant support services and of migrants is enshrined in the Declaration of cross-cultural awareness among the Japanese public. Alma- Ata (1978) and states receiving coun- Conclusion Access to social support networks of various tries should take a comprehensive approach types appears to be an influential factor affecting the to healthcare of such sojourners beyond mental well-being of international migrants in Japan. basic infectious disease control.5 Accord- More research is necessary on how to promote such ingly, migration is increasingly recognised as © Author(s) (or their connections to foster a more inclusive and multicultural a structural socio-economic force that influ- employer(s)) 2019. Re- use Japanese society amid rapid demographic change. ences health outcomes as a social determi- permitted under CC BY-NC. No PROSPERO registration number CRD42018108421. nant of health, in general, and mental health, commercial re- use. See rights 6 7 and permissions. Published by in particular. BMJ. As the world’s third largest economy, Japan Community and Global Health, INTRODUCTION was home to 2.2 million international migrants University of Tokyo, Bunkyo- ku, Global migration has increased markedly in in October 2018. This figure represents about Japan recent decades and international migrants, in 2% of the national population and approxi- Correspondence to 2016, constituted 3.4% of the global popula- mately 200 000 foreign nationals were newly 1 8 Professor Masamine Jimba; tion. International migrants are considered settled during that year. While the number of mjimba@ m. u- tokyo. ac. jp to be ‘any person who lives temporarily or foreign residents settling in Japan continues Miller R, et al. BMJ Open 2019;9:e029988. doi:10.1136/bmjopen-2019-029988 1 Open access BMJ Open: first published as 10.1136/bmjopen-2019-029988 on 3 November 2019. Downloaded from to accelerate, the total population of Japan is predicted Reporting Items for Systematic Review and Meta- Analyses to decline by 31% from a peak of 126 million in 2016 to (PRISMA) reporting guidelines.15 87 million by 2060.9 This demographic shift is a harbinger of the future as Japan is only the first nation in human Inclusion and exclusion criteria history to experience population decline due to ‘super- Study selection was purposively designed to be broad in ageing’. Other high- income nations like South Korea, order to scope the progress of research assessing a heter- Germany and Italy are on a similar demographic trajecto- ogenous health concept in an equally diverse population. ries and such changes will likely increase the proportion Migrant was defined in line with the Japanese govern- of young foreign national populations.10 However, unlike ment guidelines as a foreign national living in Japan for other high- income countries with a history of large-scale, 3 months or more.8 Study inclusion criteria were: (1) institutional health research that includes non-citizens, 11 published research assessing mental well-being among in Japan, mainly exploratory research has been conducted international migrants in Japan; (2) quantitative and/ on the health of migrants. or qualitative methodologies examining more than one Facing a serious demographic challenge, the Japa- migrant, including systematic reviews and (3) studies nese government has begun to publicly acknowledge the published in English or Japanese. Exclusion criteria were: need for more foreign workers; however, structural issues (1) conference proceedings, expert opinions, single case continue to perturb the humanistic integration of interna- reports or reviews; (2) analysis of international tourists tional migrants. For example, a 2017 survey by the Ministry and (3) studies published prior to January 2000. Mental of Justice showed that 30% of foreign residents had expe- well- being (including mental health outcomes such as rienced discrimination in Japan, with 40% having been depression, anxiety, resilience and so on) must have been rebuffed when seeking housing and 25% had been denied assessed using a standardised research method including a job due to their nationality.12 Additionally, the Migra- epidemiological surveys, interviews or medical records. tion Integration Policy Index recently highlighted strict working visa requirements and a culture of overwork and harassment in Japan leading to occupational morbidity;13 SEARCH STRATEGY such ‘push’ factors may impact the positive functioning of Electronic databases were searched for publications migrants trying to integrate into Japanese society. published between January 2000 and September 2018. The WHO defines mental health as, ‘a state of well- Studies published before 2000 were excluded in order to being where every individual can realise his or her own better reflect the demographic characteristics of contem- potential, can cope with the normal stresses of life, can porary migrant populations in Japan which have changed work productively and fruitfully, and is able to make a dramatically over the past two decades. The following contribution to her or his community’.14 Mental well- databases were queried: PubMed, UTokyo Resource being is a dual continuum that includes mental health Explorer (UTREE; includes ProQuest, SpringerLink, http://bmjopen.bmj.com/ and positive functioning open to sociocultural inter- ScienceDirect) and Web of Science; as well as Japanese pretation and includes concepts such as contentment, databases, Igaku- chuo- zasshi (Ichushi; https:// search. absence of negative life determinants, absence of disease jamas. or. jp/) and J- STAGE (https://www. jstage. jst. go. or economic prosperity.14 jp/), each of which cite over 300 000 articles per year Japan, as a host nation, has a unique cultural and from 2500 Japanese biomedical journals. The search was linguistic context in which the mental well-being and completed in September 2018, and the English as well as