Prevalence of and factors influencing Hikikomori in Osaka City, Japan: A population-based cross-sectional study.

OBJECTIVES: Hikikomori is commonly defined as a social condition in which individuals avoid social participation and relationships beyond their family members by confining themselves to a room or their house for 6 months or longer. Hikikomori has been predominantly considered a problem among young people; however, as the population is ageing, hikikomori has also emerged as a social issue among adults. Nevertheless, no comparative studies have examined the differences in the factors associated with hikikomori among teenagers/young adults and middle-aged/older adults. Thus, this phenomenon has not been thoroughly examined, and it remains unclear whether the risk factors vary between teenagers/young adults and middle-aged/older adults. Based on the Japan Cabinet Office's definition of hikikomori, this cross-sectional study evaluated the prevalence and related factors of hikikomori among the working age population (15-64 years), utilising univariate and multivariate analyses. The study also compared differences in the prevalence of and factors related to hikikomori between teenagers/young adults and middle-aged/older adults.

METHODS: We distributed self-administered questionnaires to individual participants and their families between 24 December 2020 and 18 January 2021.

RESULTS: Data from an anonymised sample of 3,092 individuals (split into two groups of 15-39 and 40-64 years) were subjected to analysis. The results revealed a hikikomori prevalence of 2.3% in the target population; the prevalence rate was 2.12% among individuals aged 15 to 39 years and 2.42% among those aged 40 to 64 years. The analysis demonstrated strong correlations between hikikomori and several factors, including unemployment, truancy, a history of psychiatric consultation or hospitalisation, being male and the absence of ibasho , which is defined as a place where individuals can feel peace, security, acceptance and belonging. The factors associated with hikikomori differed between teenagers/young adults and middle-aged/older adults.

CONCLUSION: Our findings, thus, contribute to existing research by providing a comparative analysis of risk factors across different age groups.