yes, that's exactly the point, you can't prove it. Depression is just an aggregate term of all associated symptoms. You can prove it as you do with other diseases, such as cancer, bacteria infections, etc.
My point is to be cautious with the claim "My depression causes xyz.", because your (and my) depression ARE the symptoms THEMSELVES
so far we do not know what causes them. The symptoms might be just part of your (and my) personality.
Believing in such claims could foster a victim mindset, which is not healthy. It prevents you from examining the real cause of the symptoms.
yeah nobody knows what the hell is depression. we can't say "yeah it's a certain mood different from all others" or "it's a specific problem with a brain chemical".
But I know it's the depression or whatever it is that causes the symptoms. I know there's an issue in my brain, some chemical thing. how do I know? because the only 2 things that managed to made me feel better were drugs. both that heavily target serotonin.
microdosing psilocybin made me feel like... 10% better but couldn't keep up due to other issues interfering. ssri made me like 30%, almost all symptoms were improved. but well... it only lasted around 3 symptoms before exploding (pssd).
so, I call that brain chemical problem, depression.
I disagree it's part of the personality. a disease is not part of personality. but again, how do you measure personality? it's the same dilemma.
whether it is a victim mindset, depression, personality, whatever... it doesn't matter. the result is what matter. and the result here is suicide.
in fact, both foster a victim mentality. "oh it's my depression" "oh it's my personality".
but I also disagree with that. depression doesn't foster a victim mentality. it fosters a "I have to fix this fucking disease before it kills me" mentality.
because if we can prove it's part of personality (which we can't using scientific tools) then that's worse. there's no way stop the inevitable.
How do you examine the real cause? what if there is no real cause? what if you never find it? does the real cause really matters? I don't think so. if it's trauma: probably. if it's genetics or brain acting wackly... then why it matters?