[PeterisP]

Strong, persistent correlation between A and B generally implies that it's one of three scenarios: A->B, B->A, or C->A + C->B.

In cases where it's not possible to do proper experiments to explicitly test A->B hypothesis, you'd say that correlation implies causation in the (not that rare) scenario where you have strong reasons to believe that B->A is not possible (e.g. the increase in teen suicides IMHO did not cause the increase in screen time) and you have thoroughly went through all the plausible confounders (C's) and have argumentation/evidence why that's not the case. In that case it's still not solid proof, but it's certainly a good implication and worth considering as likely true until further analysis or evidence.