Adolescents and young adults with social withdrawal in France: Sociodemographic characteristics and validation of the French version of the Hikikomori Questionnaire-25 (HQ-25)

Background: Clinical situations marked by severe social withdrawal in youths are increasingly recognized as an important public health issue in European countries, while the relation with the hikikomori syndrome initially described in Japan remains poorly investigated.Aims: This study aims to describe the sociodemographic features of adolescents and young adults with social withdrawal in French and to validate a French version of the Hikikomori Questiuonnaire-25 (HQ-25).Method: An online questionnaire was completed by 450 participants aged 13 to 25 years. In addition to socio-demographic features, participants were questioned about several aspects of social withdrawal behaviors and a version of the HQ-25 previously adapted in French by a group of patients and clinician experts.Results: A minority of participants was found 'at-risk HKM' (3.6%). They were approximately younger, and lived more frequently with their parents, with balanced sex ratio and no differences regarding the educational level. The level of distress and concern about physical/mental health did not discriminate between the two groups. Regarding psychometric properties of the HQ-25, Cronbach's alpha of the total was .93, the ICC was .74, and the indices of fit found in the confirmatory factorial analysis of the original three-factor solution were robust.Conclusions: Considering the social invisibility and the barriers to care access of adolescents and young adults with hikikomori, the development of a self-assessment instrument with good psychometric properties is regarded as an important first step.