I suppose the thing to keep in mind is that a war or a pandemic or a natural disaster will not suddenly cause all mental illness to disappear. In fact it might just make it worse in those afflicted.
Reports from recent wars and regional pandemics seems to indicate that it’s not “might” - it *does* make it worse in those that are already afflicted and it can cause it to appear in those who were not previously thought afflicted. Also, “cabin fever” is a real thing.
There’s a lot of people around these days that don’t take stress real well.