A nationwide study on time spent on social media and self-harm among adolescents.

Self-harm among adolescents has increased in many countries, but few studies have examined possible explanations. One explanation could be the changes in the way adolescents socialize and use of social media. We explored the relationship between past year self-harm and time spent on social media, employing data from a nationwide cross-sectional survey among students in grades 8 through 11 in Norway (N = 37,268). The association was estimated in logistic regression models and we adjusted for identified confounders and stratified on gender, age group and depressive symptoms. A total of 16.1% of the study population reported to have self-harmed in the past year. This proportion was elevated among those spending more than 3 h daily on social media (unadjusted OR = 2.74 (CI 2.58.-2.90)). Adjustment for confounders modified the association (OR = 1.49 (CI 1.39-1.60)). In stratified analyses, adjusted OR did not differ significantly by gender or age The association between time spent on social media and self-harm was weaker among adolescents with severe depressive symptoms (adjusted OR = 1.38 (CI 1.22-1.55)), than among those with mild or no symptoms (adjusted OR = 1.70 (CI 1.56-1.86)). Risk of self-harm was elevated among those who spent 3 or more hours daily on social media, also after controlling for other factors. Further studies are needed to explore the nature and underlying mechanisms of this association. Strengthening the evidence will help informing the development of adequate measures to prevent self-harm.