Originally Posted by
Thage
That's not how mental illness works. When someone with suicidal ideation makes the commitment to go through with it, the inciting incident is usually the straw that broke the camel's back after many, many near-misses where they decided against it. When you're already coping with intense feelings of helplessness, irrelevance, or other similar feelings, getting a tidal wave of people telling you to off yourself can have the same effect as, metaphorically-speaking, pushing someone and letting gravity do the rest of the work.
So yes, a 'trivial thing' can be an inciting incident, but it's important to note these are usually prolonged situations. Cyberbullying, to run with a previously-used example, does have established effects on peoples' mental well-being, and prolonged use of social media has been found to hold direct correlations with rising anxiety and depression in under-40s (although it's one of many contributing factors, it is a contributing factor). Humans are ultimately social creatures, and even the most introverted or self-sufficient person generally seeks positive attention/reinforcement from peers and role models.
Consistent negative attention over a long period of time cranks up the brain's natural tendency to remember negative situations (a leftover survival mechanism from our ungabunga days when bad experiences were memorized to prevent dying to those same circumstances later, same place the fight-or-flight response comes from) and drown out the positive experiences, even if objectively there are fifty positive experiences for every tweet saying 'Kill yourself, nobody wants you around.' This is exacerbated exponentially if you're dealing with suicidal ideation already.
Sorry for the wordy response. This is something where a lot of context comes into play and it bears restating that the human brain is simultaneously an extremely complicated and very basic organism, and this paradox is why what seems trivial to you or I can be the inciting incident that causes someone to stand on a bridge and lean forward.