Investigating the effect of social networking site use on mental health in an 18–34 year-old general population; a cross-sectional study using the 2016 Scania Public Health Survey

BACKGROUND: Social Networking Sites (SNS) are commonly used, especially by young adults. Their impact on mental health is unclear. Moreover, little is known about how social factors, e.g. Perceived Emotional Support (PES), may affect this association. Mental health issues are increasingly burdening the young generation and society as a whole. This study aims to investigate the association between frequency of SNS use and number of SNS contacts with the mental health of a young, Swedish population. Additionally, the potential effect modification of PES will be analysed in regard to these relationships. METHOD: This cross-sectional study applied logistic regression analyses to data on 1341 participants (aged 18–34), retrieved from the Scania Public Health Survey (2016). Analyses were stratified by gender and the GHQ-12 scale assessed poor mental health. A 2-way interaction model was used to test for effect modification by PES regarding the association between SNS use and mental health. RESULTS: Increased risk for poor mental health was found in women only. Using SNS almost hourly vs. less often resulted in an odds ratio (OR) of 1.66 (95% confidence interval (CI) = 1.16–2.38). The corresponding figures for having ≥600 contacts vs. ≤599 were (1.89; 1.21–2.97). Having low PES and using SNS almost hourly was associated with an OR of 3.12 (CI = 1.69–5.76; synergy index (SI) = 1.25). Low PES and ≥ 600 contacts resulted in an OR of 6.07 (CI = 1.73–21.33), whereby interaction was detected (SI = 2.88). CONCLUSION: Women, but not men, with frequent SNS use and a high number of SNS contacts were more likely to have poor mental health, which was exacerbated in women with low PES. Facilitating PES could be an approach for improving mental health among young adults. Future studies on the use of SNS should focus more on gender analyses. SUPPLEMENTARY INFORMATION: Supplementary information accompanies this paper at 10.1186/s12889-020-09732-z.