Problematic smartphone use, but not daily duration of use, is associated with anxiety and depression in adolescents

Background: Increasing anxiety and depression in adolescents has paralleled an increase in smartphone use. However research has found a lack of evidence between smartphone use and poor mental health outcomes. ‘Problematic smartphone use’ (PSU) refers to a pattern of smartphone use, and connected feelings and thoughts, that bears a resemblance to an addiction. The objective of this study was to explore the association between PSU and anxiety, depression and insomnia amongst adolescents.

Methods: A cross-sectional study of adolescents aged 16 to 18 years from five schools in England was undertaken. We conducted a mixed-effects multivariable logistic regression to explore the association between PSU (using the validated Smartphone Addiction Scale Short-Version [SAS-SV]) and moderate anxiety symptoms (GAD-7 ≥10) and symptoms of depression (PHQ-9 ≥10). We adjusted for school year, gender, and ethnicity and used structural equation modelling to explore PSU with insomnia as a mediating effect on anxiety and depression.

Results: 657 adolescents from five schools (median age: 17.5 (17-18 [IQR]), 77.3% female) were included. PSU was associated with anxiety and this association remained when adjusted for duration of use (aOR= 2.03, 95% CI 1.27-3.34). PSU was associated with both depression, (aOR=2.96, 95% CI1.80-4.86) and insomnia, adjusted for duration of use (aOR=1.64, 95% CI 1.08-2.50). Daily duration of use was not associated with anxiety or depression, though it was associated with insomnia (aOR=1.15, 95% CI 1.06-1.24-, p<0.001). Insomnia has an indirect partial mediating effect on anxiety (0.05 95% CI 0.03-0.08 p<0.001) and depression (0.07 95% CI 0.04 - 0.10 p<0.001)

Conclusion: This is the first UK study exploring the relationship between PSU and mental health conditions amongst adolescents using validated scoring tools. PSU was significantly associated with anxiety and depression, while duration of use was not. Longitudinal research is needed to establish the direction of the association. Problematic pattern of use, rather than daily duration of use, may be more important in understanding mental health harms associated with smartphones.