["I don't go out anymore": an analysis of voluntary social withdrawal among Italian 15-19-year-old students].

Objectives: to analyse the prevalence and characteristics of the hikikomori phenomenon in Italy within a representative sample of students aged 15 to 19 years, assessing the factors associated with this behaviour to guide preventive interventions.

Design: cross-sectional study based on anonymous data collected through the ESPAD®Italia (European School Survey Project on Alcohol and other Drugs) survey using a self-administered questionnaire.

Setting And Participants: a representative sample of Italian high-school students is selected annually to ensure the comparability of ESPAD®Italia estimates. In this study, the pooled 2021-2023 sample consists of 36,868 students (50.8% male), with an average age of 17.0 years (standard deviation: 1.4).

Main Outcomes Measures: the outcomes analysed are having experienced voluntary social withdrawal for at least six months over a lifetime (Lifetime Hikikomori) and the current behaviour of never leaving the house during the week (Current Withdrawal).

Results: in 2023, 2.0% of students reported having voluntarily isolated themselves for at least six months in their lifetime, with a slightly higher prevalence among girls. Current withdrawal involved 11.3% of students, a significant increase compared to the previous two years. In the pooled 2021-2023 sample, the analysis of independent variables showed that the hikikomori phenomenon is associated with the use of psychotropic drugs, cigarette smoking, having been a victim of cyberbullying, feelings of exclusion, dissatisfaction in friendships, risky behaviours related to internet and video game use, and belonging to non-traditional families. The current withdrawal is directly associated with cigarette smoking, lack of enjoyment in social interactions, overweight/obesity, and belonging to non-traditional families.

Conclusions: the study provided the first quantitative estimate of voluntary social withdrawal among Italian students aged 15-19 years, confirming that the phenomenon is widespread and concerning, especially among girls. Factors such as the perception of social exclusion, problematic online behaviours and the use of psychotropic drugs are strongly associated with the phenomenon. Future longitudinal research could further explore these relationships and support the development of integrated educational strategies in schools to identify and support at-risk students.