Annoni, Anna Maria Petrocchi, Serena Camerini, Anne-Linda Marciano, Laura 2021 Background: The pervasiveness of smartphones has raised concerns about an increase in the prevalence of problematic smartphone use (PSU), which depends on a set of psychological and behavioral risk factors. Previous research has yielded mixed results on factors predicting PSU, including social anxiety and trust. In particular, the role of trust remained largely unexplored. In the present study, we aimed to investigate the relationship between social anxiety and PSU, via the mediating role of time spent on the phone, and to explore the moderating role of dispositional trust toward others, by using a moderated mediation model with PSU as the outcome. Methods: A total of 240 young adults (Mage = 23.33, SD = 3.90, 50% male) answered an online questionnaire, which included the 12-item Social Anxiety Scale, a question on the daily duration of smartphone use, a single-item measure of dispositional trust, and the 10-item Smartphone Addiction Scale Short Version. Gender and occupational status were included as covariates. Results: Social anxiety was significantly and positively related to PSU; however, smartphone use did not mediate this relationship. Although the relationship between smartphone use and PSU was significant and positive, the link between social anxiety and smartphone use was not. Dispositional trust moderated and strengthened the direct relationships between social anxiety and PSU as well as smartphone use and PSU. Conclusions. Heavy smartphone users as well as socially anxious individuals, with the tendency of trusting others, are more at risk of PSU, which can be explained by their preference and search for online connections. application/pdf https://n2t.net/ark:/12658/srd1319315 https://susi.usi.ch/global/documents/319315 https://susi.usi.ch/documents/319315/files/Annoni_2021_MDPI_ijerph.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.3390/ijerph18052452 info:eu-repo/semantics/altIdentifier/ark/12658/srd1319315 info:eu-repo/semantics/openAccess CC BY International journal of environmental research and public health. - 2021, vol. 18, no. 5, p. 15 p Problematic smartphone use Social anxiety Trust Moderation Mediation Young adults info:eu-repo/classification/udc/65 The relationship between social anxiety, smartphone use, dispositional trust, and problematic smartphone use : a moderated mediation model http://purl.org/coar/resource_type/c_6501