The impact of higher levels of autistic traits on risk of hikikomori (pathological social withdrawal) in young adults

PLOS ONE RESEARCH ARTICLE The impact of higher levels of autistic traits on risk of hikikomori (pathological social withdrawal) in young adults Mark Brosnan ID*, Jeff Gavin Department of Psychology, Centre for Applied Autism Research, University of Bath, Bath, United Kingdom * a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 Abstract Background Hikikomori is an extreme state of social withdrawal, originally identified in Japan but more recently recognised internationally. Many countries imposed restrictions during the COVID19 pandemic which may have had a detrimental impact on those at risk of hikikomori, specifically young adults and those with high levels of autistic traits. OPEN ACCESS Citation: Brosnan M, Gavin J (2023) The impact of higher levels of autistic traits on risk of hikikomori (pathological social withdrawal) in young adults. PLoS ONE 18(2): e0281833. https://doi.org/ 10.1371/journal.pone.0281833 Editor: Carmen Concerto, University of Catania Libraries and Documentation Centre: Universita degli Studi di Catania, ITALY Received: November 14, 2022 Accepted: February 1, 2023 Published: February 21, 2023 Copyright: © 2023 Brosnan, Gavin. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: ������ PA @ ACCEPT please confirm DOI is active������ We have placed anonymised data in a digital repository: 10.6084/ m9.figshare.22016198. Funding: The authors received no specific funding for this work. Aims To explore whether levels of autistic traits mediate the relationship between psychological wellbeing and hikikomori risk. We also looked at whether autistic traits mediated between lockdown experiences (e.g. not leaving the house) and hikikomori risk. Methods 646 young people (aged 16–24) from a wide range of countries completed an online questionnaire assessing psychological wellbeing, autistic traits and experiences of lockdown for this cross-sectional study. Results Autistic traits mediated the relationship between both psychological wellbeing and hikikomori risk, as well as frequency of leaving the house during lockdown and hikikomori risk. Greater hikikomori risk was associated with poor psychological wellbeing, higher autistic traits and leaving the house less frequently during the COVID-19 pandemic. Conclusions These findings suggest similarities with Japanese hikikomori research and are consistent with suggestions that psychological wellbeing and COVID-19 restrictions are associated with increased hikikomori risk in young adults, and both associations are mediated by higher levels of autistic traits. Competing interests: The authors have declared that no competing interests exist. PLOS ONE | https://doi.org/10.1371/journal.pone.0281833 February 21, 2023 1 / 13 PLOS ONE Hikikomori, autistic traits, wellbeing Introduction Hikikomori is a form of pathological social withdrawal or social isolation whose essential feature is physical isolation in one’s home. The person must meet the following criteria: 1. Marked social isolation in one’s home; 2. Duration of continuous social isolation for at least 6 months; 3. Significant functional impairment or distress associated with the social isolation [1–4]. In Japan, hikikomori is diagnosed in 1–2% of the general adult population [5,6], with a higher rate in younger adults specifically (4.6%, [7]). Initially, hikikomori was considered to be a ‘collectivist culture-bound’ syndrome unique to Japan. However, hikikomori is now recognised as an international phenomenon, associated with social and cultural shifts brought about by modernization, globalization, and the rise of the Internet [1,8]. Hikikomori has been identified in a wide range of countries, including some that are less collectivist (more individualist [9,10]), namely, Australia, Bangladesh, Brazil, Canada, China, France, India, Iran, Italy, Nigeria, Oman, Singapore, South Korea, Taiwan, Thailand, Ukraine, and the USA [11–13]. Hikikomori is now considered to be a boundless global, cross-cultural syndrome, most prevalent in urban areas of high-income countries [9,11,14]. Hikikomori can result in people becoming economically inactive in the long-term. Hikikomori is associated with not being in education, employment, or training (‘NEET’), which is a marker of long-term disadvantage [15]. Researchers in Japan have therefore focused upon identifying the factors that impact upon ‘hikikomori risk’ and elevated hikikomori risk has been identified in young adult males (aged 16–24; [5,14,16–18]). A study of hikikomori risk amongst Japanese university students, found that 22% of the sample were considered to be at risk of hikikomori [19]. Co-occurring mental health conditions are highly prevalent in hikikomori, however hikikomori is argued to be distinguishable from both mood disorders (such as anxiety and depression, [14]) and withdrawal conditions associated with psychotic and schizophrenia-like disorders and other personality disorders [1,12]. Specifically, hikikomori has been found to co-occur in around a third of people diagnosed with Autism Spectrum Disorder (ASD: [14,20–22]). ASD is characterized by difficulties with social communication and social interaction and restricted and repetitive patterns in behaviors, interests, and activities [23,24]. Thus, whilst there are similarities between ASD and hikikomori around social interaction, ASD is defined in terms of social difficulties whereas hikikomori is defined in terms of social withdrawal. Though ASD and hikikomori are distinguishable, the high level of co-occurrence between the conditions may be related to both groups being high in levels of autistic traits [25]. Autistic traits are argued to be distributed continuously across the population, higher in men than women, and are characterised by differences in attention to detail, attentional focus, social skills, communication, and imagination [26–29]. Autistic traits are not diagnostic of ASD, although autistic groups are unsurprisingly higher in autistic traits than non-autistic groups [30]. Hikikomori self-report higher levels of autistic traits than non-hikikomori in Japan [25,31]. During the recent pandemic, many countries imposed COVID-19 restrictions, some of which limited the extent to which people can leave their houses (‘lockdown’; [32,33]). This may have contributed to hikikomori risk for those susceptible to the condition [17,34–40]. Autistic traits predict increased negative emotional response to COVID-19 [41], with higher levels of autistic traits predicting a greater negative emotional response. Consequently, it has been argued that we needed to pay attention to the psychological wellbeing of those with higher levels of autistic traits during and after the COVID-19 pandemic [42,43] and to ensure that hikikomori are n (...truncated)