Comment by guerrilla

The problem with that theory comes when people who have all of that and more get depressed. I do think you have a point in that the cause can be external but I think to see it as social is far too limited. Then there are cases where it's entirely internal as well, depression being a symptom of various illnesses. I'm not sure if you know this but a lot of theraputic work does focus on solving external problems. You might also observe that there can be quite a catch-22 effect or bootstrapping problem here as well.