Can we ever show causality between social media use and mental health issues?

Yet another study has just been published linking social media use with anxiety and depression in young people, particularly in girls. The correlation is now undeniable, as study after study shows it. But, as my 23-year old daughter immediately countered when I mentioned it to her, is it causal?
The most recent Canadian study shows just how much the mental health of girls seems to be affected by cellphone use, and by social media use in particular, and the extent to which girls are affected more than boys. It is just the latest in a string of such studies. And logically it makes good sense, and thoughtful articles like this one from the Child Mind Institute explain how the phenomenon might work, and how it might be more than just a coincidental case of mental health deteriorating year on year at the same time as social media usage is also increasing year on year. But even the fact that girls tend to use social media more than boys, and girls' mental health tends to be more fragile than that of boys, is not enough to definitively make the correlation causal (as the Child Mind Institute also grudgingly concludes).
But it's SO close, especially when we consider that a major exception to the social media - mental health correlation tends to occur in those girls that are avid users of social media but who also keep up an active real world social life, suggesting that it is the lack of face-to-face engagement that may be causing the youth depression we are seeing (although social media may well be exacerbating that movement away from physical socializing and exercise in young people). My own daughter has managed to carry on a pretty active physical social life and a good exercise regime and still has ended up some anxiety and depression issues. Also, she had managed to apply herself academically and get good school results, despite her social media habits, although the intense pressure to perform in school is probably another candidate for the mental health issues thst beset today's youth.
In fact, so tangled is the whole issue that we may never be able to prove causality. Do people who are socially isolated spend more time on social media, or do users of social media develop "perceived social isolation"? Is the fear of missing brought on by artificial or "curated" social feeds causing anxiety and depression, or are depressed individual more likely to perceive FOMO?
But the correlation is so strong as to be as near causal as we are ever likely to be able to show. Not that this helps us much anyway. What are we going to do? Deny cellphones to our teens? Monitor all their social media usage? That is not going to end well, we're it even practicable or possible.