Yet Another Study Shows No Link At All Between Social Media And Teen Anxiety And Depression (TechDirt)

As the authors of the paper note, many other papers trying to make this link have used perhaps questionable proxies for mental health:

A major shortcoming of existing research is that studies have conceptualized mental health problems in a variety of ways (e.g., reduced well-being, psychological distress, poor self-esteem, depressive symptoms). Because social media use may relate differently to different mental health problems (e.g., social anxiety versus overall well-being), these inconsistent findings may be due to studies not assessing the same phenomenon. Studies have also typically relied on self-reports of both social media use and mental health, thereby running the risk of inflating relations due to a common methods bias. Studies assessing more strictly defined mental health problems and measuring such problems by other means than self-report are needed.