Hikikomori is a psychopathological and social syndrome, initially identified in Japan, predominantly observed among adolescents and young adults, characterized by prolonged social withdrawal. The term originates from Japanese, meaning "to withdraw" or "to be confined." It is used both to describe the act of avoiding social contact and the individuals who experience this condition. This phenomenon is marked by adolescents and young adults confining themselves to a single room in their homes—typically their parents’ residences—for months or even years, avoiding school, work, or other social interactions. Individuals rarely leave their rooms except for basic physical needs and often spend extended periods engaged in activities such as internet use, reading, or video gaming.

Definition and Diagnostic Criteria

Although there is no universally accepted definition of Hikikomori, Japanese psychiatrists and the government have developed operational criteria to describe the condition. The Ministry of Health, Labour and Welfare (MHLW) of Japan established criteria in 2003 and 2010, which required that an individual’s lifestyle be home-centered, that they exhibit little or no interest or willingness to attend school or work, and that the symptoms persist for at least six months. This condition reflects social withdrawal that excludes social participation (school, work, or external interactions) and is sustained by remaining at home. The initial MHLW criteria of 2003 also required the exclusion of schizophrenia or other mental disorders for a Hikikomori diagnosis. However, influenced by international research, the diagnostic criteria revised by Kato and colleagues in 2020 indicated a shift in clinical practice.

Epidemiology

According to the 2016 data from the Cabinet Office of Japan, approximately 540,000 individuals aged 15–39 were socially withdrawn for more than six months. By 2019, the estimated number of Hikikomori aged 40–65 had increased to 610,000, indicating an aging Hikikomori population.【1】 Regarding demographic characteristics, symptom onset typically occurs during adolescence, while the age of first clinical presentation is generally in the twenties.【2】 The majority of cases are male, with reported male-to-female ratios exceeding 3:1.

In connection with this condition, there is a societal concern in Japan referred to as the “8050 Crisis,” which highlights the unsustainable situation arising when Hikikomori offspring in their 50s live with parents in their 80s, who may begin to experience physical, financial, or cognitive difficulties.【3】 

Etiology and Contributing Factors

The emergence of Hikikomori is explained by an interplay of biopsychosocial factors. Psychological and familial factors include introverted personality traits, extreme shyness, avoidant or insecure attachment patterns, and childhood trauma. Experiences such as peer bullying, parental rejection or overprotection, and heightened sensitivity to criticism may also predispose individuals to this syndrome. Social and cultural factors further contribute to its manifestation.

The rigid and standardized educational and examination system in Japan can create feelings of failure and anxiety about meeting parental and societal expectations, leading individuals to seek relief through withdrawal into the family environment. Moreover, the fragmentation of social structures and crises in traditional values in modern society are considered contributing societal factors. Advances in information technologies, reducing opportunities for direct socialization, have also been implicated in the increase of Hikikomori cases.

Differential Diagnosis and Comorbidity

Although social withdrawal is a core feature of Hikikomori, differential diagnosis encompasses a spectrum of psychiatric conditions, as many mental disorders—including schizophrenia, anxiety disorders (social phobia, OCD), major depressive disorder, and avoidant personality disorder—are associated with social isolation. Approximately half of Hikikomori cases (reported rates ranging from 33% to 54.5%) exhibit psychiatric comorbidity.【4】 

Common comorbidities include pervasive developmental disorders, generalized anxiety disorder, dysthymia, adjustment disorder, schizophrenia, personality disorders (avoidant, schizoid, obsessive-compulsive), and internet addiction. Cases without coexisting mental disorders are referred to as “primary Hikikomori,” whereas those with concurrent psychiatric disorders are labeled “secondary Hikikomori,” although the usage of these terms is debated.

Culture-Bound Syndrome Debate and Globalization

Initially, Hikikomori was conceptualized as a “culture-bound syndrome” specific to Japan. However, similar cases have now been reported across Asian countries (South Korea, China, Thailand, Singapore, India, Iran), as well as in Europe, North and South America, Oceania, and Africa. This globalization suggests that Hikikomori has become a global issue reflecting modern societal challenges, rather than solely a Japanese cultural expression, and may be understood under the framework of “cultural concepts of distress.” For instance, there are reported cases in Turkey associated with this syndrome.

Treatment and Prognosis

Treatment of Hikikomori generally requires a multidimensional approach. Family support constitutes a key component of intervention. Parents are advised to avoid punitive or commanding approaches and instead provide interaction that allows the patient to initiate communication or actions independently. Early psychotherapeutic intervention has been associated with improved treatment prognosis. Although neurobiological factors such as immune system functioning, oxidative stress, and the social brain network have been suggested, there is currently limited information on therapeutic applications targeting these mechanisms.

Furthermore, concerns have been raised that social restrictions and quarantines implemented during the COVID-19 pandemic may have increased the risk of Hikikomori-like social withdrawal.

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