Clarifying the position of hikikomori in mental health: Is hikikomori a variant of already-known mental health disorders? A review of the literature

Abstract

Hikikomori was included in the chapter “Culture and Psychiatric Diagnosis” of the DSM-5-TR Section III as an example of cultural concepts of distress. However, attempts over time to better define hikikomori emphasized different specific characteristics/criteria. The present study aimed to provide an overview of different criteria and definitions of hikikomori, and to examine whether hikikomori resembles social anxiety/phobia (and avoidant personality), depression, and adjustment and stress disorders. This narrative review followed available recommendations on reporting standards. A structured literature search was conducted in PubMed, MEDLINE, PsycINFO, PsycARTICLES, Web of Science, and Scopus on May 31, 2023. Hikikomori definitions and criteria diverge in their focus on specific criteria such as not working/attending school, avoidance/refusal of and disinterest/unwillingness to participate in social situations and relationships. Hikikomori resembles a (severe) variant of social anxiety disorder, a form of adjustment disorder, or a variant of depressive disorder, depending on the criteria in use. Empirical evidence on the clinical validity of some hikikomori definitions is scarce. If hikikomori criteria do not include indicators of dysfunction, the condition under study may reflect severe/extreme social isolation rather than a different diagnostic category. Updated hikikomori research criteria were proposed to foster future studies addressing diagnostic validity and clinical comorbidity. Alternatively, a “with (social) withdrawal” specifier in the definition of social anxiety, depressive, and adjustment and stress disorders should be considered. Finally, the inclusion of hikikomori in the DSM-5-TR was discussed.