A recent study from Harvard University found the opposite :

If you’ve ever thought a break from social media might be good for your head space, new research suggests you’re onto something.

In a study of young adults published in JAMA Network Open, those who participated in a one-week social media detox experienced a boost in their mental health, with symptoms of anxiety dropping by 16.1 percent, depression by 24.8 percent, and insomnia by 14.5 percent.

https://news.harvard.edu/gazette/story/2025/12/social-media-detox-boosts-mental-health-but-nuances-stand-out/

Another study from MIT found that social media is bad for mental health:

https://mitsloan.mit.edu/ideas-made-to-matter/study-social-media-use-linked-to-decline-mental-health