There are a few conflicting frameworks, plus what I describe is normative behavior rather than people with diagnosable conditions (depression in abnormal psychology tends to be more a dysfunction of the brain). I teach social psychology to undergraduates, so I'm familiar with the other frameworks at a fairly broad level-- the one the person you responded to is a bit of an older perspective, but the direction you're taking I've heard discussed.

Still, it's difficult to get into the details in a Lemmy comment on a shower thoughts thread.

None the less, I mostly don't like the fragile/secure ego approach because it's harder to measure something like that, meaning there's less evidence that's what's going on.

I will say more generally though, our brains seek out acceptance and avoid rejection, much like we do physical pain (fMRI confirms it's the same part of the brain). That includes good things, like behaving cooperatively, and bad things, like confirmation bias. Self-esteem, similarly, cuts both ways-- it makes us feel better without needing external sources of esteem, but it also rejects external threats to that self esteem.

I simply worry that excess of anything leads to bad outcomes, like certain politicians we're dealing with now. But now we're getting more into my opinion and less about the research.

If you're curious, the textbook I use is open source. https://opentextbc.ca/socialpsychology/

It's not perfect, though. I find it covers the topic well enough not to need to force my students to buy a text.