"Hikikomori” is known since the 80s and was described by Saito in 1998 as a different clinical picture from any current diagnostic category, being social withdrawal the most important aspect. Young hikikomoris, more than a million in Japan (Teo2010), withdraw in their room for at least six months, interrupting communication with the outside world. This picture was described by many international scholars (Watts 2002; Zielenzinger 2008; Teo 2010; Piotti et al.2014). Part of international literature, after DSMIV-TR, defined hikikomori as a culture-bound syndrome (Agugliaetal.,2010). However, recently similar cases were described in different contexts, both in Asia and Western world (Kato et al.,2012), highlighting peculiar clinical signs influenced by the context, although maintaining a common matrix referred to Saito framework.

This literature review aims to gather descriptions of hikikomori in different cultures, to identify cross-cultural variables on which the phenomenon is based and to analyse any differences in clinical manifestations.

Eighty-two articles which contained ‘hikikomori” in the title or abstract were reviewed and searched using online databases (PsycINFO, PubMed, googleschoolar)

The scientific literature was divided by year of publication and by three phases:

1. The articles are mostly Japanese

2. Western articles, referring to Japanese contexts

3. The Hikikomoriconcept isclosely related tosocial withdrawal (sources from many countries).

The literature shows a tendency to consider hikikomori a phenomenon which exceeds cultural context (although influenced by it), rather than a culturally characterized syndrome.

Clinical psychologists and psychiatrists consider the social withdrawal and the loss of interest in the human environment as potential signals of distress and mental illness. A particular form of social withdrawal is the hikikomori sindrome, identified in Japan (Saito, 1998). The hikikomori are called “family heremits” or “bedroom heremits”.

The UFSMIA Arezzo has received during last years a number of requests to take care of hikikomori adolescents. The research collects clinical data useful to the assessment.

The research analyzed a number of clinical cases focusing the interest on five early adolescents in treatment. The researchers compared the different anamnesis, the symptomatology, likeness and difference in the teenagers life style.

The work identifies some aspects in common from the five subjects of the study. These characteristics can be used as signals of the hikikomori sindrome among early adolescents in a Italian cultural context. The hikikomori’s life style is centered on the own home; he/she presents an extreme withdrawal from peer group and a refusal of school; there is not a diagnosis of other significant psychiatric disorders; it is always present a distortion of the sleep-wake cycle and a conflict with parents.

The phenomenon of hikikomory sindrome appears also with the beginning of adolescence. The signs of disease are in large part similar to the Japanese descriptions, although if the researchers noticed some aspects tipical of the italian cultural context.

In schizophrenia, perceptual inundation related to sensory gating deficit can be evaluated “off-line” with the sensory gating inventory (SGI) and “on-line” during listening tests. However, no study investigated the relation between “off-line evaluation” and “on-line evaluation”. The present study investigates this relationship.

A sound corpus of 36 realistic environmental auditory scenes was obtained from a 3D immersive synthesizer. Twenty schizophrenic patients and twenty healthy subjects completed the SGI and evaluated the feeling of “inundation” from 1 (“null”) to 5 (“maximum”) for each auditory scene. Sensory gating deficit was evaluated in half of each population group with P50 suppression electrophysiological measure.

Evaluation of inundation during sound listening was significantly higher in schizophrenia (3.25) compared to the control group (2.40, P < .001). The evaluation of inundation during the listening test correlated significantly with the perceptual modulation (n = 20, rho = .52, P = .029) and the over-inclusion dimensions (n = 20, rho = .59, P = .01) of the SGI in schizophrenic patients and with the P50 suppression for the entire group of controls and patients who performed ERP recordings (n = 20, rho = −.49, P = .027).

An evaluation of the external validity of the SGI was obtained through listening tests. The ability to control acoustic parameters of each of the realistic immersive environmental auditory scenes might in future research make it possible to identify acoustic triggers related to perceptual inundation in schizophrenia.

The Japanese Saito coined the term “hikikomori” to define an extreme form of social withdrawal, particularly present in Japan (1998). In the West there is an increasing frequency of adolescents hikikomori.

The UFSMIA Arezzo has received a number of requests to take care of adolescents bearing strong similarities to hikikomori teenagers or “on the way of the social withdrawal”. These admissions have led to an epidemiological study in order to quantify these behaviors among very young teenagers in a Italian town.

The research used a questionnaire addressed to the coordinator teachers of the middle schools of Arezzo (2694 students). The questionnaire collected information on the single student absent from school for more than 40 days asking reasons for the absence.

Absents from school for more than 40 days not for an illness were 27. The average age was 14,5 years, 59,3% males, 40,7% females. The 66,6% of the students repeated one or more times a year of school. The teachers do not know the reasons for the absences for 29,6% of students but for 51,9% they indicate psychological problems as the main reason of the absences. The 40,7% of students showed difficulty waking up, leaving home, coming to school, difficulty in relating to others and low self-esteem. These signs could bring to identify hikikomori subjects.

The research shows that the school is not able to recognize a student hikikomori, but it can provide valuable informations to identify a teenager with social withdrawal.

Social withdrawal is a potential signals of distress and mental illness such as psychosis, mood disorders, anxiety (Kirkcaldy & Siefen, 2012). The term 'hikikomori” defines a particular form of social withdrawal recognized in Japan at the end of the last century (Saito, 1998). At the moment in all the west world (United States, France, United Kingdom, Spain, Italy) there is an increasing frequency of adolescents and young people who show symptoms of hikikomori like a life style centered on the own home and refusal of the school.

Requests to take care of social withdrawal teenagers (hikikomori) are increasing. This work describes two cases in treatment of early adolescents.

Authors analyse the terapeutic steps of the clinical treatment of two very young teenegers arrived to the Public Health Service because their extreme social withdrawal. The work focusses the attention on the relationship with the patients, the families and the social context.

The two cases show that the treatment of hikikomori sindrome is complex. A single type of approach (e.g. individual psychoterapy or family therapy) is not sufficient. Combining different patterns it is possible to create a network of treatments able to promote the resources of subject and of his/her familiar and social context.

Results underline the necessity of increasing the clinical knowledges on the social withdrawal sindrome and creating new protocols useful for the treatment.