Associations of problematic smartphone use with depressive symptoms and suicidal ideation in university students before and after the COVID-19 outbreak: A meta-analysis

•The meta-analysis evaluated association of PSU and depression in university students.•PSU was found to be associated with depression.•The association may become stronger after COVID-19 pandemic.•PSU was found to be associated with suicidal ideation in university students. Problematic smartphone use (PSU) has been suggested to present with depressive symptoms and suicidal ideation (SI) as well as sleep disturbance, lack of social support, and emotional isolation. The aim of this systematic review and meta-analysis was to evaluate the association between PSU with depressive symptoms and SI in university students, and to determine the potential influence of the coronavirus disease 2019 (COVID-19) outbreak. Observational studies pertinent to our research were identified through comprehensive searches of the PubMed, Embase, Cochrane Library, and Web of Science databases. To account for potential heterogeneity, the random-effects models were employed to aggregate the findings. Eighteen datasets from 17 case-control studies, including 24,019 university students, were included. Among them, 8,775 (36.5 %) had PSU. A higher prevalence of depressive symptoms (odds ratio [OR]: 2.40, 95 % confidence interval [CI]: 2.19 to 2.63, p