the mindset can be literally everything see, that's why i prefer going full chemist mode on psychiatry cause if we get on the mindset...
i met a woman in the past who could handle unimaginable amounts of abuse irl+online, i think* she might had been BPD
no reactions, no rage, no self pitying blah blah
one day her mother called her " a waste" like just that, one word, she attempted suicide
so in the end when it comes to vulnerable emotions or anything nihilistic, dark, and self destructive, we got a clear case of complexity
and given how you mentioned personal
i used to be able to handle anything irl (still can and more due to juggernaut mode) like two years ago i could handle job/college/family/mental/emotional issues
one single goal that i truly cherished went to hell, poof it all crumbled
so there's no really a formula, and that's just mentioning two people with two specific ticks, i could probably write you a whole book of possibly reasons to be depressed, in theory literally everything can become a proper reason to be sad about, hence a proper reason to be depressed about
all about timing + accuracy