@article{5996cbd6af8442719d170266e8a9b17e,
title = "Development and validation of the 25-item Hikikomori Questionnaire (HQ-25)",
abstract = "Aim: Hikikomori, a form of severe social withdrawal, is an emerging issue in mental health, for which validated measurement tools are lacking. The object was to develop a self-report scale of hikikomori, and assess its psychometric properties and diagnostic accuracy. Methods: A sample of 399 participants from clinical and community settings completed measures. Psychometric properties were assessed with factor analysis; diagnostic accuracy was compared against a semi-structured diagnostic interview. Results: The Hikikomori Questionnaire contained 25 items across three subscales representing socialization, isolation, and emotional support. Internal consistency, test–retest reliability, and convergent validity were all satisfactory. The area under the curve was 0.86 (95% confidence interval, 0.80–0.92). A cut-off score of 42 (out of 100) was associated with a sensitivity of 94%, specificity of 61%, and positive predictive value of 17%. Conclusion: The 25-item Hikikomori Questionnaire (HQ-25) possesses robust psychometric properties and diagnostic accuracy in an initial sample of Japanese adults. Additional research on its psychometric properties and ability to support clinical assessment of hikikomori is warranted.",
keywords = "cultural syndrome, diagnosis, mental health, psychometric, social isolation, social withdrawal",
author = "Teo, {Alan R.} and Chen, {Jason I.} and Hiroaki Kubo and Ryoko Katsuki and Mina Sato-Kasai and Norihiro Shimokawa and Kohei Hayakawa and Wakako Umene-Nakano and Aikens, {James E.} and Shigenobu Kanba and Kato, {Takahiro A.}",
note = "Funding Information: We thank Dr Koji Tanaka, Dr Akifumi Inuo, Dr Nobuki Kuwano, Dr Keita Kurahara, Ms Sakumi Kakimoto, Ms Yoko Zushi, and Ms Satomi Nagai for assistance with data collection in the clinical sample and data entry. Drs Teo and Chen are supported by the Department of Veterans Affairs, and the views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the United States government. This work was supported in part by grants from the: Japan Society for the Promotion of Science (JSPS) Bilateral Joint Research Project between Japan–USA (to Drs Kato and Teo); Japanese Ministry of Education, Culture, Sports, Science, and Technology Innovative Areas {\textquoteleft}Will Dynamics{\textquoteright} (JP16H06403 to Dr Kato); Pfizer Health Research Foundation Japan (to Drs Kato and Teo); Japan Agency for Medical Research and Development (AMED) (Syogaisya-Taisaku-Sogo-Kenkyu-Kaihatsu-Jigyo JP17dk0307047 & JP18dk0307073 & JP18dk0307075 to Drs Kato and Kanba; Yugo-No JP18dm0107095 to Dr Kato); JSPS Kakenhi (JP15K15431 to Dr Kato); Young Principal Investigators{\textquoteright} Research Grant of the Innovation Center for Medical Redox Navigation, Kyushu University (to Dr Kato); and the Senshin Medical Research Foundation (to Drs Kato and Kanba). The funders did not have any role in the study design, collection, analysis, and interpretation of the data, nor in the writing of the report and the decision to submit the paper for publication. Drs Teo and Kato, the corresponding authors, had full access to the data in the study and had final responsibility for the decision to submit for publication. Publisher Copyright: {\textcopyright} 2018 The Authors. Psychiatry and Clinical Neurosciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Psychiatry and Neurology",
year = "2018",
month = oct,
doi = "10.1111/pcn.12691",
language = "English (US)",
volume = "72",
pages = "780--788",
journal = "Psychiatry and Clinical Neurosciences",
issn = "1323-1316",
publisher = "Wiley-Blackwell",
number = "10",
}