Lupin finding the kids with depression and teaching them Patronuses so the dementors don’t affect them as much
McGonagall keeping a stash of chocolate all of Harry’s third year because she knows which kids will be most affected by the Dementors and also which kids she can bring into her office with that excuse because they’re having a breakdown
Hogwarts teachers desperately trying to make sure all their students with depression avoid the Dementors
Alternately, the kids with depression being the first to face off against a Dementor because they know all the tricks.
The kids with depression defending the other kids when one passes by because they know how to function in the grey.
The kids with depression having the biggest, gaudiest patronuses because they have power.
They’ve already learned how to survive a Dementor long before they had magic.