Maybe a distinction should be made between people who are aware of their source of depression and people who are not? Like it makes sense to be depressed if you're living in abject poverty. People can point to it and say I know why I'm depressed. That seems different from someone who lives in a secure environment, feels valued, has meaningful relationships, engages in rewarding work, etc. All these things that should lead to a happy life but this person still feels bad. That's definitely a different thing, no?