Autism Spectrum Conditions in Hikikomori: A Pilot Case-Control Study.

AIM Hikikomori, a form of pathological social withdrawal, has been suggested to have comorbidity with autism spectrum disorder (ASD). This study aimed to clarify how characteristics of hikikomori are associated with ASD including undiagnosed autism spectrum conditions (ASC) in clinical settings. METHODS 416 clinical patients were recruited through the Mood Disorder/Hikikomori Clinic at Kyushu University Hospital. 103 hikikomori cases and 221 clinical controls without hikikomori conditions were extracted using a semi-structured interview, and completed a series of self-rated scales including Autism-Spectrum Quotient (AQ-J). RESULTS Compared to non-hikikomori controls, hikikomori cases were likely to have higher autistic tendency based on AQ-J. The cases showed more severe subjective depressive symptoms based on self-rated BDI-II, whereas no significant difference was found on interview-based severity evaluation using HAMD. Comparison within hikikomori cases based on the cut-off score of AQ-J revealed that hikikomori cases with high ASC were significantly more likely to have higher traits of modern-type depression (MTD), smaller social networks and less social support. CONCLUSION The present data has suggested hikikomori sufferers are more likely to have autistic tendency, and hikikomori sufferers with high ASC may have much more difficulty in social communication and social interaction. In addition, those with high ASC may also have lower self-esteem and higher complaint tendencies as aspects of MTD traits, which may relate to the occurrence of hikikomori. Thus, evaluating autistic tendencies is important for appropriate interventions in hikikomori. Further investigations should be conducted to validate our pilot findings using structured diagnostic systems of ASD. This article is protected by copyright. All rights reserved.