Proposing diagnostic criteria for hikikomori

Jan 2020
(Cited/modified from Kato et al. World Psychiatry 2020 & Psychiatry and Clinical Neuroscience 2019)


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.

The behavior of staying confined to home—the physical aspect of withdrawing and remaining socially isolated—is the hikikomori’s central and defining feature. Individuals who occasionally leave their home (2–3 days/week), rarely leave their home (1 day/week or less), and rarely leave a single room may be characterized as mild, moderate, and severe, respectively. Individuals who leave their home frequently (4 or more days/week), by definition, do not meet criteria for hikikomori. The estimated continuous duration of social withdrawal should be noted (e.g., 8 months). Individuals with a duration of continuous social withdrawal of at least 3 (but not 6) months should be noted as pre-hikikomori.
The requirements for avoidance of social situations and relationships are not mandatory features. Distress or functional impairment should be carefully evaluated. While impairment in the individual’s functioning is vital to hikikomori being a pathological condition, subjective distress may not be present. Many patients feel content in their social withdrawal, particularly in the earlier phase of the condition. Not a few patients frequently describe a sense of relief at being able to escape from the painful realities of life outside the boundaries of their home. As the duration of social withdrawal gets longer, most patients begin endorsing distress, such as feelings of loneliness. Patients tends to co-occur with other psychiatric conditions, while comorbidity of other psychiatric disorders are not as an exclusionary criterion for hikikomori.


The following specifiers are not mandatory criteria; however, they may be useful for additional characterization of hikikomori:

  1. With lack of social participation.
    The individual occasionally (2–3days/week) or rarely (1 day/week or less) participates in activities, such as attending school, going to a workplace, or going to medical appointments. This specifier would likely apply to hikikomori who are also not in education, employment, or training (i.e., ‘NEET’).
  2. With lack of in-person social interaction.
    The individual occasionally (2–3 days/week) or rarely (1 day/week or less) has meaningful in-person social interactions (conversations) with people outside home. In severe cases, the individual rarely has in- person social interaction even with cohabitating people, such as family members. This specifier would likely apply to individuals with hikikomori who have social interactions that primarily occur via digital communication technologies (e.g., social media, online gaming).
  3. Indirect communication.
    Due to the proliferation of the Internet in modern society, ‘indirect’ communication via web-based or other technologies is increasingly common. Thus, such indirect communication should be assessed in accordance with direct communication. Some cases have daily bidirectional indirect communication via online tools such as social networking services and/or online games.
  4. With loneliness.
    The individual endorses feeling lonely. The presence of loneliness tends to be more common as the length of hikikomori increases.
  5. With a co-occurring condition.
    Hikikomori may co-occur with numerous psychiatric disorders, such as avoidant personality disorder (e.g., isolation due to fears of criticism or rejection), social anxiety disorder (e.g., avoidance of social situations because of fear of embarrassment), major depressive disorder (e.g., avoidance of social situations as a reflection of neurovegetative symptoms), autism spectrum disorder (deficits in social interactions and communication), or schizophrenia (e.g., isolation due to positive and negative symptoms of psychosis).
  6. Age of onset.
    In many cases, the age at onset is adolescence and early adulthood; however, cases with onset after the third decade are not rare.
  7. Family pattern and dynamics.
    Socioeconomic status and parenting styles may influence the development of hikikomori. For instance, overprotective parenting and/or absence of paternal involvement are suggested to be linked to the occurrence of this phenomenon.
  8. Cultural background.
    Pathological social withdrawal was originally characterized and described in Japan and more recently has been identified in other countries, especially in East Asia and Europe. Sociocultural situation may influence this condition.
  9. Intervention.
    Even though no evidence-based interventions have been established, pharmacotherapy (if the individuals are comorbid with psychiatric disorders), a variety of psychotherapy, social work, and family approach have been provided. Precision (individualized) approach is recommended based on the above assessments.


Original work:
Kato TA, et al. Defining pathological social withdrawal: proposed diagnostic criteria for
hikikomori ,World Psychiatry, 19(1), 116-117, 2020