Except this trend didn't happen at any previous downturn, so now you're special pleading that this economic downturn specifically is different somehow, based on... What exactly? And again, these mental health trends are international and cross-cultural and none of the other explanations can account for this. In fact, your suggestion that it's due to economic downturn is essentially refuted since even nations that didn't experience a downturn saw these mental health declines.
> Adults' feelings, anxiety, pressure usually propagate through kids.
What about adult anxiety about the Vietnam war, the nuclear threat of the cold war, the anxiety over terrorism that took out the twin towers. No meaningful blips seen with those momentous events.
You keep pointing to possible second and third order effects that maybe-somehow-sort-of indirectly filtered down to kids through mechanisms like "parental anxiety", instead of a direct and obvious first-order effect from a device that's literally in their hands 16 hours of the day, and whose use we know has been algorithmically optimized to drive engagement, fear and anger, and whose second order effects are known to disrupt sleep, which is particularly important for teens going through puberty.
Like, don't you see how absurdly implausible your second and third order effects are by comparison? To say nothing of the fact that they don't even explain all of the data, which is not a problem for the social media hypothesis.