The claim that heavy social media use is linked to mental health issues is true. According to the article linked in the original post, "...the Royal Society for Public Health, Britons aged 14-24 believe that Facebook, Instagram, Snapchat and Twitter have detrimental effects on their wellbeing. On average, they reported that these social networks gave them extra scope for self-expression and community-building. But they also said that the platforms exacerbated anxiety and depression, deprived them of sleep, exposed them to bullying and created worries about their body image and 'FOMO' ('fear of missing out'). Academic studies have found that these problems tend to be particularly severe among frequent users." This quote shows that while social media can sometimes have positive effects like a sense of community and the ability to express oneself, young social media users also report that social media platforms heightened anxiety, depression, sleep deprivation, body image issues, cyberbullying, and a fear of missing out. This shows that the positive uses of social media can still be outweighed by the comparison platforms' cause, leading to poor mental health. An article from the Standford University Law & Biosciences Blog states that a link between social media use and poor mental health has been observed in numerous studies and research papers, "A systematic review found that the use of social networking sites is associated with an increased risk of depression, anxiety, and psychological distress ... though not by itself proof of causation, at least some reason for concern." This suggests that there is not yet any causal evidence that social media use causes poor mental health, but there is certainly a correlation. Additionally, the National Library of Medicine states, "A number of studies have been conducted on the impacts of social media, and it has been indicated that the prolonged use of social media platforms such as Facebook may be related to negative signs and symptoms of depression, anxiety, and stress." Therefore, according to multiple credible sources, while there is no exact causal evidence that social media causes poor mental health, it's been observed that there's a link between frequent social media use and poor mental health.
Sources:
-https://www.economist.com
-https://law.stanford.edu
-https://pmc.ncbi.nlm.nih.gov/articles/PMC7364393/