This is turning into a great thread and this comment is the most impactful one for me. I'm going to give it a go. My daughter is 18 and at least half her peer group are in a dreadful state in terms of mental health. You have to wonder if the impact of the modern media environment is way worse than we've comprehended. Of course that's totally unempirical but is the funding there for the studies we need? In any case it's easy to run the personal experiment, as you've suggested.