Validation of the German version of the 25‐item hikikomori questionnaire 25

Objectives The 25‐item Hikikomori Questionnaire (HQ‐25) is an instrument developed to measure a condition characterized by extreme social withdrawal that was first described in Japan. This study aimed to translate the HQ‐25 into German and validate the German version (HQ‐25‐G). Methods Translation was conducted according to established guidelines. Validation was based on data from a quota sample of individuals living in Germany, ranging from 18 to 74 years old (representing the distribution of age, sex and federal state, n = 5000). Data collection occurred during August and September 2023. We tested reliability, construct validity and concurrent validity. Moreover, HQ‐25 scores for key sociodemographic group were reported. Results Internal reliability for the HQ‐25‐G was excellent (Cronbach's alpha = 0.93). We confirmed the original three‐factor model. Moreover, higher hikikomori levels were significantly associated with more depressive symptoms (r = 0.50), more anxiety symptoms (r = 0.45), higher loneliness levels (r = 0.56), higher levels of objective social isolation (r = −0.47), higher levels of perceived social isolation (r = 0.59) and a higher preference for solitude (r = 0.45). Conclusions In a large population‐based sample (including younger adults, middle‐aged adults and older adults), the HQ‐25‐G version proves to be a psychometrically robust instrument, which is useful for further exploring the phenomenon of hikikomori within the German‐speaking population.