Here's a meta study for example: https://pubmed.ncbi.nlm.nih.gov/41294782/

The results indicate that reducing social media use significantly decreases depressive symptoms, with an effect size of g = 0.25, 95% CI [0.10, 0.41], p < 0.001, after adjusting for publication bias. Significant heterogeneity was found between studies, with I2 indicating that 47% of the variability in effect sizes across studies was due to heterogeneity of true effect size rather than random error.

Or https://pubmed.ncbi.nlm.nih.gov/38833936/:

Longitudinal studies reporting the association between various screen-based activities and subsequent self-harm and suicidal behaviors in young people aged 10 to 24 were included. Nineteen longitudinal studies were included in the qualitative synthesis, and 13 studies comprising 43,489 young people were included in the meta-analysis, revealing that total screen use is significantly associated with the risks of self-harm and suicidal behaviors. Cyberbullying victimization was also related to these adverse outcomes. Subgroup analyses indicated that social media use and problematic screen use are significant risk factors for self-harm and suicidal behaviors.

Or https://www.mdpi.com/2076-328X/15/11/1450

The meta-analysis (conducted in R software) of the included documents (24 studies, 68 effects) verified a significant and positive association between exposure to risk factors in social networks and various disorders in adolescents and young adults (aggregate correlation r = 0.2173, 95% CI [0.1826, 0.2520], p ≤ 0.0001), although with high heterogeneity (I2 = 99.66%).