You really missed the point. He's saying "depression" means a lot of different things[0], and that many people are unhappy simply because their societal (economic and social) situation sucks and thus their life sucks.

[0]: It would be interesting to have a discussion about "depression" without actually using the word, since it's so overloaded.

Poor not in wealth but in quality of life, which is almost everyone.

No not at all. Rich people who benefit from the system can also be victim to it in other ways. Not all managers are sociopaths and I’m sure a lot of them feel shit about some of the things they have to do in order to maintain their jobs. And everyone, regardless of wealth and status, is subject to the “slings and arrows of outrageous fortune” and whatever personal tragedies they may bring. As I said we need finer grained diagnoses. You might have for example:

- Catatonic depression, likely physical in nature

- Shit Life Syndrome [1], likely societal cause, possibly other issues are play

- Privilege Pathos, likely caused by past trauma, loss or existential issues

These are obviously exaggerated groupings to make the point. At the end of the day, at the receiving end of every diagnosis is an individual with a unique biology and backstory that lead to their depression. But if you want to have the most impact on reducing the ever skyrocketing amount of depression cases, you would be best to focus on the societal issues and that, in my opinion, is what is causing the most symptoms in the most amount of people. The people in the other two categories (the catatonic and the rich) are the people most likely to be currently receiving treatment anyway, the first because they can no longer look after themselves and so wind up in the system and the second because they have the means to access therapies.

[1] - https://en.wikipedia.org/wiki/Shit_life_syndrome?wprov=sfti1