Experts in the Japanese phenomena of hikikomori say the condition of extreme social isolation is more widespread than previously acknowledged, and it deserves a clear and consistent definition to improve treatment across the globe.
In an article published in the February issue of the journal World Psychiatry, experts cite a lack of broad clinical understanding of the condition.
Although hikikomori is typically associated with young adults in Japan, the researchers say many of the same criteria of extended social isolation apply to people around the world, including among older adults and stay-at-home parents.
A simplified and clear definition will improve the recognition and subsequent treatment for people who suffer from the condition, the authors write.
The article highlights four key aspects of the newly proposed definition of hikikomori:
* Confined at home: The proposed definition clarifies the frequency of time spent outside the home, while still meeting the definition of “marked social isolation.”
* Avoiding people: Some people choose to avoid social situations and interaction not because they’re anxious but because it meets their comfort level. The newly suggested definition therefore removes the avoidance of social situations as a criteria.
* Better defining distress: Many people diagnosed with hikikomori report that they feel content in their social withdrawal. However, as the duration of social withdrawal gets longer, their distress and feelings of loneliness increases.
* Other disorders: Co-occurring mental health conditions such as depression should not exclude patients from also being assessed for and diagnosed with hikikomori.
“In our view, the frequency of co-occurring conditions increases the importance of addressing social withdrawal as a health issue,” they write.
Senior author Alan Teo, M.D., associate professor of psychiatry in Oregon Health & Science University School of Medicine and a researcher and psychiatrist in the VA Portland Health Care System, said the medical profession hasn’t traditionally recognized social isolation as a health issue.
“There is a cultural issue within the house of medicine whereby we don’t pay attention to it and don’t think it is in our lane to deal with,” he said.
“These are shared problems, whether it’s an 80-year-old Portlander who’s a meals-on-wheels recipient living by herself or an 18-year-old with hikikomori in Japan.”
Spending time online can be damaging when it substitutes for interacting with people face to face, Teo said. Those person-to-person social relationships are a critical aspect of mental health.
Ironically, modern tools to improve communication may be having the opposite effect.
“With advances in digital and communications technologies that provide alternatives to in-person social interaction, hikikomori may become an increasingly relevant concern,” the authors write.
Spending time online can be damaging when it substitutes for interacting with people face to face, Teo said. Those person-to-person social relationships are a critical aspect of mental health.
“Your social life is critical to your quality of life – yet in health care, we often forget to think about that,” Teo said.
“A person’s day-to-day social life is really what brings them meaning and value.”
In addition to Teo, the other authors included Takahiro A. Kato, M.D., Ph.D., and Shigenobu Kanba, M.D., Ph.D., of Kyushu University in Japan.
The recommendations published online today in World Psychiatry represent an outgrowth of earlier collaboration between the three authors, including a perspective published in the journal Psychiatry and Clinical Neurosciences in 2019.
Funding: Teo’s work is supported by a Career Development Award (CDA 14-428) from the U.S. Veterans Health Administration Health Service Research and Development and the HSR&D Center to Improve Veteran Involvement in Care. The views expressed in the paper are those of the authors and do not necessarily reflect the position nor policy of the U.S. Department of Veterans Affairs of the U.S. government.
The term ‘Hikikomori’ derives from Japanese, and it is composed of the verb ‘hiki (hiku)’, which means to move back, and ‘komori (komoru)’, which means to come into.1 2 In the last two decades, the ‘Hikikomori’ syndrome (HS) has been conceptualised as a psycho-sociological condition characterised by prolonged and severe social withdrawal for a time period of at least 6 months.3–5
This condition has been reported and studied first in the Japanese society/culture.6 In the first epidemiological research conducted in 2003,7 8 the Japanese Ministry of Health, Labour and Welfare defined it as a state in which a young individual
(a) mainly stays at home,
(b) cannot or does not engage in social activities, such as going to school or working,
(c) has continued in this state for 6 months or longer,
(d) has neither a psychotic disorder nor a medium to lower level of mental retardation (IQ <55–50) and (e) has no close friends.
Social withdrawal in the HS typically involves staying at home almost all days.6 9 Some authors have proposed two subtypes of social withdrawal behaviour characterising the HS: the ‘hard core’ subtype, including those youths who never leave their room and never talk to their families and the ‘soft’ subtype, including those cases who go out and talk to others occasionally.10
More recently, Kato and colleagues11 have proposed another subtyping of the HS, distinguishing between those cases who live with their families—this group represents the majority of the HS population—and those who live alone, representing about 11%. Typically, severe social withdrawal behaviour affects males (4:1 male-to-female ratio), mostly the young adult eldest son of a family with a good socioeconomic and cultural level. Age of onset can vary from 20 to 27 years, but prodromal symptoms often emerge during early adolescence.6 8
It has been hypothesised that some of the socially withdrawn youths have close friends but do not maintain contact with them during social withdrawal or that do not have any close friends but maintain alternative, less-demanding personal relationships with others such as online friends.12
Socio-cultural influences have been believed as key factors involved in the development of this condition, such that some authors have proposed the inclusion in the DSM-5 ‘culture-bound’ syndromes chapter as a Japanese syndrome.13
The role of cultural aspects was supported in other psychiatric disorders which similarly to the HS share social withdrawal as a key component or maintenance factors such as psychotic disorders, social anxiety disorder, depressive disorders, obsessive-compulsive disorder, and Internet addiction.14–20
Other researchers and clinicians believe that this form of social withdrawal behaviour is only a symptom of a wide variety of major psychiatric disorders listed in DSM-IV and the current DSM-5 (eg, psychotic disorders, depressive disorders, social anxiety disorder, agoraphobia, schizoid or avoidant personality disorder, Internet addiction).21
Consistent with the latter hypothesis, the concept of ‘secondary Hikikomori’ has been proposed to define those cases whose severe social withdrawal behaviour is a manifestation of a subtype of another psychiatric disorder or even a consequence of a primary psychiatric disorder.12
Other authors suggest that a considerable subset of the cases present with clinical features that do not meet the criteria for any of the existing psychiatric disorders13; hence, it has been suggested that the HS could be considered as a primary new psychiatric disorder in a future version of the DSM, despite having some clinical overlap with other disorders.22
Consistent with this hypothesis, Kondo and colleagues23 reported that in a group of patients aged 16–35 years with onset of social isolation before age 30 for at least 6 months, 8% had schizophrenia, 26% had an anxiety disorder, 8% had a depressive disorder, 23% had a personality disorder (including 6 with Avoidant, 6 with Schizoid, and 4 with obsessive-compulsive personality disorder).
As recently summarised by Kato et al,24 at the present time whether it is other psychiatric disorders that give rise to hikikomori as a symptom or whether it is indeed HS that is the cause of co-occurring major mental health conditions has not been clearly established; thus, it could be argued that both possibilities exist.
The authors identified a group of psychiatric disorders characterised by hikikomori-like features including psychosis, social anxiety disorder, avoidant personality disorder, depressive disorders, Internet addiction, and post-traumatic stress disorder.24 Such disorders would be the most frequently co-occurring ones with HS.
Other researchers suggested that the HS might not be a culture-bound syndrome depending on the socio-cultural context but that it may exist also outside Asian countries.22 Epidemiological research conducted on community general population has produced quite heterogenous prevalence data, showing that the prevalence of the HS can range from approximately 0.87%25 to 1.2% in Japan,26 to 1.9% in Hong Kong27 to 2.3% in Korea28 or up to 26.66% in student population in Japan.29
This variety may depend on differences in the inclusion criteria, assessment instruments, studies’ countries, and recruitment strategies across the studies. Research conducted in clinical samples with psychiatric disorders or in treatment-seeking population in mental health services demonstrates that the prevalence can vary from 12.64%30 up to 63.07%.28
The socio-cultural features of the HS probably involve a variety of cross-cultural factors such as the social structure (eg, the mainstreaming culture, the labelling effects, the academic expectations imposed to students which are prominent in Asian countries but also in other countries), the society’s media (eg, media enunciation when reporting the issue), the school context (eg, the bullying phenomenon), and the family relationships (eg, enmeshed parent–child relationships).1 15 18 20 22
In addition, one of most important problems related to studying this condition involves the heterogeneity in the definitions used across the studies and a lack of consensus on well-established diagnostic criteria.12 31
For example, some studies conducted in Japan have considered a duration of severe social withdrawal that is longer than 6 months as a clinically meaningful threshold, while other research conducted in Korea28 and Hong Kong32 has used a shorter duration criterion (3 months). Recently, Teo and Gaw13 conducted an online and manual systematic search of the HS criteria using the Pubmed and PsycINFO databases.
The researchers provided a proposal for diagnostic criteria based on the most recurrent clinical features and defined the HS as
(a) spending most of the day and almost every day at home,
(b) marked and persistent avoidance of social situations,
(c) the social withdrawal and avoidance interferes significantly with the person’s normal routine, occupational (or academic) functioning, or social activities or relationships,
(d) the person perceives the withdrawal as ego-syntonic,
(e) in individuals under age 18 years, the duration is at least 6 months,
(f) the social withdrawal is not better accounted for by another mental disorder (eg, social anxiety disorder, major depressive disorder, schizophrenia, or avoidant personality disorder).13 33
In the last decade, some reviews have been conducted on the HS32 34–36; however, only one study12 used well-established guidelines for systematic reviews (ie, Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria).37
Recently, Li and Wong12 conducted a systematic review of 42 qualitative and quantitative studies by searching online databases (ProQuest, ScienceDirect, Web of Science, PubMed). The authors identified 12 qualitative studies using case study designs, focus group or ethnographic research methods, 9 expert opinion papers and 3 reviews.12
In addition, 19 quantitative studies were identified: however, 3 out of them used a case series design. Out of the quantitative studies, 10 were conducted in Japan, 3 in China and 1 in Korea, thus confirming partially the socio-cultural roots of the phenomenon but also highlighting the need for research on contexts different from Asian countries.12
