Time spent on social media and depressive symptoms in university students: The mediating role of psychoactive substances.

Background and objectives: Although some studies have related social media use and depressive symptoms, little is known about the role of psychoactive substance use in this relationship. Therefore, this study aimed to estimate the association between time spent on social media (TSSM) and depressive symptoms and to examine whether this relationship is mediated by psychoactive substances in students.

Methods: Our cross-sectional analysis included a sample of students from a university in a large city in southern Brazil. The TSSM and tobacco frequency of consumption were self-reported. Depressive symptoms were assessed with the Patient Health Questionnaire. Alcohol and illicit drug-related risks were assessed with the Alcohol, Smoking and Substance Involvement Screening Test. Hayes's PROCESS macro was used for mediation analyses, adjusted for age, sex, body mass index and physical activity.

Results: A total of 3161 students were included, of which, 69.0% reported moderate to severe depressive symptoms. The association between TSSM and depressive symptoms was statistically significant and partially mediated by tobacco consumption (indirect effect [IE] = 0.05; 95% CI: 0.02-0.08), alcohol-related risk (IE = 0.19; 95% CI: 0.14-0.25), and illicit drug-related risk (IE = 0.08; 95% CI: 0.05-0.12).

Conclusion and scientific significance: Our data suggest a direct relationship between TSSM and depressive symptoms, with a partial mediation effect of psychoactive substance use. This study highlights the importance that public health initiatives aimed at preventing depressive problems in young adults should focus not only on TSSM, but also on controlling and reducing psychoactive substance use.