A Complete Understanding of Hikikomori Based on Epidemiological Methods and Evaluation of Social Reintegration Support Programs Using RCTs

2022 Fiscal Year Final Research Report

• Project/Area Number: 16K09081
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Epidemiology and preventive medicine
• Research Institution: Seirei Christopher University
• Principal Investigator: Oba Yoshitaka 聖隷クリストファー大学, 社会福祉学部, 教授 (20440604)
• Co-Investigator(Kenkyū-buntansha): 武井 教使 浜松医科大学, 子どものこころの発達研究センター, 教授 (80206937)
• Project Period (FY): 2016-04-01 – 2023-03-31
• Keywords: ひきこもり / 不登校 / 自殺 / 無業 / 神経発達症 / 精神疾患 / 心理社会的支援 / 社会疫学

Outline of Final Research Achievements

Due to ethical issues and the impact of COVID-19, we were unable to conduct a study using RCTs. However, the following results were obtained：①A self-administered survey of 10,000 young adulthood (aged 19-39) randomly selected from the residential registry in city H was completed up to the second round of the survey by mail. 1090 responses were received for the first round and 787 for the second round. We redefined Hikikomori into two groups, "Definition A: home Hikikomori" and” Definition B: social interaction avoidance" with 0.5% for A and 1.7% for B. Both groups had significantly higher K10 scores and significantly higher suicide-related behaviors than the control group.②Prolonged absence from the 7th grade to the 12th grade predicted unemployment (OR=1.68, p=0.007), even after to adjusted for covariates.

Free Research Field

小児発達学

Academic Significance and Societal Importance of the Research Achievements

①ひきこもりにおいては、厚生労働省や内閣府が用いている定義とは異なる11項目で測定した。結果は、Leeらの2.3％(2013)，Wong らの1.9％(2015c)の数値と近く，妥当な推定値であることが示唆された。②中学から高校の不登校は、K10や1年前の無業を共変量として調整しても、無業に関連することが示唆された。
これらから、ひきこもりや無業、自殺等の問題はメンタルヘルスを主とする専門職だけではなく、教育、福祉、産業、司法等、広く社会と共有し、介入と予防について議論していく必要がある。