Validation of the HRI-24 on Adolescents and Development of a Short Version of the Instrument

The Hikikomori phenomenon often starts during adolescence and, once it develops, it tends to persist. Thus, having an instrument specifically validated for detecting it at early ages could play a pivotal role to reduce the chronicity risk. This work aims to validate the 24-item Hikikomori Risk Inventory (HRI-24) on adolescents and to develop a short version of it. In Study 1, an exploratory structural equation model was used to evaluate the functioning of the HRI-24 and to select the items for inclusion in the short version. In Study 2, confirmatory factor analyses were run on the short version, and measurement invariance across gender and school levels was investigated. Structural validity and measurement invariance of the HRI-24 were supported. The psychometric properties of the short version, denoted as HRI-15, were satisfactory and analogous to those of the HRI-24, while accuracy and specificity in identifying at-risk individuals were slightly higher. Measurement invariance of the HRI-15 was supported as well. The validation of the HRI-24 on adolescents would help professionals to screen young people at the first onset of the Hikikomori phenomenon, and the short version could be highly useful in large epidemiological and screening studies.