Immigrant workers, defined as individuals who work in a country other than their country of origin, play an increasingly significant role in the Japanese economy. According to data from Ministry of Health, Labour and Welfare the number of foreign workers was 1,727,221 immigrant workers in Japan in 2022 (Ministry of Health, Labour and Welfare, 2022). While immigrant workers make valuable contributions to Japan's workforce, they also face a number of challenges that can impact their mental health. In this essay, I will discuss the mental health challenges faced by immigrant workers in Japan, the consequences of poor mental health, and the social policies that should be implemented by the Japanese government to facilitate the mental health of immigrant workers.

One major challenge faced by immigrant workers in Japan is language barriers. Difficulty communicating in Japanese can lead to misunderstandings and difficulties at work, as well as isolation and loneliness outside of work. Immigrant workers who have lower levels of Japanese proficiency experience higher levels of stress and difficulty adjusting to life in Japan (Asis & Carandang, 2020). Improving access to language learning resources, such as Japanese language classes, could help immigrant workers overcome this challenge and improve their mental health.

A review of mental well-being of immigrants in Japan indicated that discrimination and prejudice can also negatively impact the mental health of immigrant workers in Japan. Immigrant workers may face discrimination based on their race, ethnicity, or nationality, and this can lead to feelings of exclusion and marginalization (Miller at al., 2019). In a survey of Japanese Brazilian immigrants in Japan, researchers found that those who experienced discrimination were more likely to report mental health problems, such as depression and anxiety (Asakura et al., 2008). Addressing discrimination and promoting diversity and inclusion in the workplace and society at large is crucial for improving the mental health of immigrant workers in Japan.

Long working hours is another contributing factor to poor mental health of immigrant workers in Japan. In a study about Chinese factory workers, it was indicated that workers who worked relatively long hours showed depressive symptoms and poor health outcomes (Date et al., 2009). Workplaces should therefore be inspected and sanctions should be imposed if workers work more than the set hours.

Isolation and a lack of social support can also contribute to poor mental health among immigrant workers in Japan. Immigrant workers may struggle to build social networks and find support in their new country, especially if they are living far from their families and communities of origin (Luo & Sato, 2021; Miller et al., 2019). Providing opportunities for immigrant workers to connect with others, such as through social clubs or community groups, can help alleviate feelings of isolation and improve mental health.

In addition to these challenges, immigrant workers in Japan may also experience difficulty , depending on their resident status, which can be stressful and contribute to poor mental health such as developing depressive symptoms (Thi et al., 2022). Ensuring that immigrant workers have access to legal support and assistance with documentation issues can help alleviate this stress and improve mental health.

Finally, economic insecurity and job insecurity can also have a negative impact on the mental health of immigrant workers in Japan. Many immigrant workers in Japan hold non-regular, or part-time or temporary jobs, which can be unstable and offer few protections or benefits (Tsuda & Cornelius, 2002). Economic insecurity and job insecurity can lead to stress and anxiety, as well as difficulties in meeting basic needs, such as housing and healthcare (Nappo, 2022). The rights of migrant workers must be protected by preventing illegal dismissals and ensuring job security.

In conclusion, mental health is a critical issue for immigrant workers in Japan. Challenges such as language barriers, discrimination and prejudice, isolation and a lack of social support, cultural differences, legal and documentation issues, and economic insecurity and job insecurity can all contribute to poor mental health among immigrant workers in Japan. Poor mental health can have serious consequences, including decreased productivity and job performance, negative impact on physical health, increased risk of mental health disorders, and difficulty integrating into society. To support the mental health of immigrant workers in Japan, the government should implement social policies such as improving access to mental health care and support services, promoting employment policies that support job security and fair treatment, offering programs to support language learning and cultural adaptation, addressing discrimination, and promoting diversity and inclusion, and providing legal support and assistance with documentation issues. These policies will not only benefit immigrant workers, but will also contribute to the overall well-being of Japanese society.

「移民労働者」（一般的に、出身国以外の国で働く個人のことを指す）は、日本経済においてますます重要な役割を果たすようになってきている。厚生労働省のデータによると、2022年の日本における外国人労働者の数は172万7221人である。移民労働者は日本における労働力として欠かせない存在となっている一方で、彼らは多くの課題に直面し、結果としてメンタルヘルスが悪化するケースも少なくない。このエッセイでは、日本の移民労働者が直面するメンタルヘルス上の課題、メンタルヘルス不良によって起こりうる問題、そして移民労働者のメンタルヘルスを促進するために日本政府が実施すべき社会政策について議論したい。

日本で働く移民労働者が直面する大きな問題のひとつに、言葉の壁がある。日本語でのコミュニケーションの難しさは、仕事上の障壁となり、またコミュニケーションにおける誤解につながるだけでなく、仕事以外での場面における孤立や孤独にもつながる。研究によると、日本語能力が低い移民労働者は、より高いレベルのストレスを経験し、日本での生活に適応するのが難しくなるという (Asis & Carandang, 2020)。日本語教室などの言語学習資源へのアクセスを改善することは、移民労働者が言語の壁を克服し、メンタルヘルスを向上させるのに役立つと考えらる。

日本の移民のメンタルヘルスに関する研究のレビューでは、差別や偏見も移民労働者のメンタルヘルスに悪影響を及ぼす可能性があることが示された。移民労働者は、人種、民族、国籍に基づく差別に直面することがあり、これが排除や疎外感につながることがある（Miller at al., 2019）。在日ブラジル人移民を対象とした調査では、差別を経験した人は、うつ病や不安などのメンタルヘルス上の問題を訴える可能性が高いことがわかった（Asakura et al., 2008）。日本における移民労働者のメンタルヘルスを改善するためには、差別に対処し、職場や社会全体における多様性とインクルージョンを促進することが重要である。

長時間労働は、日本における移民労働者のメンタルヘルスを悪化させるもう一つの要因である。中国の工場労働者に関する研究では、比較的長い時間働く労働者に抑うつ症状や健康状態の悪化が見られることが指摘されている（Date et al., 2009）。したがって、職場は長時間労働を規制するために監査されるべきであり、規定の時間を超えて働くケースが見られる場合には制裁が課されるべきである。

孤立や社会的支援の欠如も、日本における移民労働者のメンタルヘルス不良の一因となり得る。移民労働者は、特に家族や出身地域から遠く離れて暮らしている場合、新しい国で社会的ネットワークを構築し、相談できる相手を探すのに苦労することがある（Luo & Sato, 2021; Miller et al., 2019）。クラブや地域の集まりなど、移民労働者が他の人々と知り合う機会を提供することは、孤立感を和らげ、メンタルヘルスを向上させるのに役立つ。

これらの課題に加え、日本における移民労働者は、在留資格によってはビザの更新など法的な問題において困難を抱え、それがストレスとなり、抑うつ症状を発症するなどメンタルヘルスの悪化につながることもある（Thi et al.、2022年）。移民労働者が法的支援や在留資格取得・更新に関する支援を受けられるようにすることは、このようなストレスを軽減し、メンタルヘルスを向上させるのに役立つと考えられる。

最後に、経済的な不安や雇用の不安定さも、日本における移民労働者のメンタルヘルスに悪影響を与える可能性がある。日本では多くの移民労働者が非正規雇用、つまりパートタイムや派遣社員として働いており、不安定で保障や手当もほとんどない（Tsuda & Cornelius, 2002）。経済的不安と雇用の不安定さは、ストレスと不安につながるほか、住宅の確保や医療を受けることも難しくする（Nappo, 2022）。違法な解雇を防止し、安定した雇用を保障することで、移民労働者の権利を保護しなければならない。

References
• Asakura, T., Gee G. C., Nakayama, K., & Sayuri, N. (2008). Returning to the "homeland": Work-related ethnic discrimination and the health of Japanese Brazilians in Japan. American Journal of Public Health, 98(4), 743–50. Retrieved from https://www.researchgate.net/publication/5543567_Returning_to_the_Homeland_Work-Related_Ethnic_Discrimination_and_the_Health_of_Japanese_Brazilians_In_Japan
• Asis, E. & Carandang, R. R. (2020). The plight of migrant care workers in Japan: A qualitative study of their stressors on caregiving. Journal of Migration and Health, 1-2(2020). https://doi.org/10.1016/j.jmh.2020.100001
• Date, Y., Abe, Y., Aoyagi, K., Ye, Z., Takamura, N., Tomita, M., Osaki, M., & Honda, S. (2009). Depressive symptoms in Chinese factory workers in Nagasaki, Japan. Industrial Health, 47, 376-382.
• Luo, Y. & Sato, Y. (2021). Relationships of social support, stress, and health among immigrant Chinese women in Japan: A cross-sectional study using structural equation modeling. Healthcare, 9(3), 258; https://doi.org/10.3390/healthcare9030258. Retrieved from https://www.mdpi.com/2227-9032/9/3/258
• Ministry of Health, Labour and Welfare (2022). 「外国人雇用状況」の届出状況まとめ（令和３年10月末現在） (Summary of "Status of Employment of Foreign Nationals" [as of October 31, 2021]). Retrieved from https://www.mhlw.go.jp/stf/newpage_23495.html#:~:text=%E5%A4%96%E5%9B%BD%E4%BA%BA%E5%8A%B4%E5%83%8D%E8%80%85%E6%95%B0%E3%81%AF%201%2C727%2C221%20%E4%BA%BA%E3%81%A7%E3%80%81%E5%89%8D%E5%B9%B4,%E3%81%8B%E3%82%89%203.8%E3%83%9D%E3%82%A4%E3%83%B3%E3%83%88%E3%81%AE%E6%B8%9B%E5%B0%91%E3%80%82
• Miller, R., Tomita, Y., Ong, K. I. C., Shibanuma, A., & Jimba, M. (2019). Mental well-being of international migrants to Japan: a systematic review. BMJ, 1-8. https://doi.org/doi:10.1136/bmjopen-2019-029988
• Nappo, N. (2022). Self-perceived job insecurity and self-reported health: Differences between native-born and migrant workers based on evidence from the Sixth European Working Conditions Survey. PLoS ONE 17(4): e0267252. https://doi.org/10.1371/journal.pone.0267252
• Thi, H. T., Kitajima, T., Takeshi, S., & Hiroko, M. (2022). Mental health and associated factors for Vietnamese migrants in Japan during the COVID-19 pandemic: A comparative analysis on resident status. Research Square, 1-25. https://doi.org/10.21203/rs.3.rs-1552849/v1
• Tsuda, T., & Cornelius, W. A. (2002). Labor market incorporation of immigrants in Japan and the United States: A comparative analysis. IZA Discussion Paper No. 476, 1-40. Retrieved from https://ccis.ucsd.edu/_files/wp50.pdf