Barbara Carpita Chiara Bonelli ^* Federico Giovannoni Francesca Parri Matteo Gambini Benedetta Nardi Giulia Amatori Ivan Mirko Cremone Stefano Pini Liliana Dell'Osso

• University of Pisa, Pisa, Tuscany, Italy

During the last few decades, a growing field of literature is focusing on hikikomori, a phenomenon described as a form of pathological social withdrawal or social isolation that lasts for more than 6 months leading to significant functional impairment and/or distress. Despite initially considered a culture-bound syndrome, hikikomori syndrome later gained a wider recognition in different countries, ranging from an attempt to take refuge in an idealistic world, when society success' standards are not reached, to a maladaptive coping strategy complicating several psychiatric illnesses such as anxiety disorders, major depression, internet addiction, internet gaming disorder (IGD) and autism spectrum disorder (ASD). In this framework, difficulties in social interaction, in problem solving strategies and socio-emotional reciprocity, may lead to social withdrawal and hikikomori-like behaviors. In this work, we described two cases of patients where the presence of underlying autism spectrum may have represented a sign of vulnerability towards the development of a possible fullblown case of hikikomori with IGD. This work should be considered in light of some limitations. First of all, the high number of questionnaire items. Despite HQ and AICA CVS-S are relatively short questionnaires, AdAS questionnaire requiries long compilation times increasing the risk of inaccurate and hasty answers. Conversely, large number of items allow us to explore a broad spectrum of symptoms. Moreover, all the questionnaires remain self-assessment that may lead patients to bias of symptoms' overestimation/underestimation. Finally, the report of two patients limits general considerations about treatment indications. Moreover, patients were not assessed with quantitative psychometric instruments for anxiety and mood disorders, which were instead assessed towards a clinical evaluation according to DSM-5 criteria.