Is the depression inherent to the disorder, or is it caused by the unrelenting stress brought on by living in an environment that is actively hostile to this in

Is the depression inherent to the disorder, or is it caused by the unrelenting stress brought on by living in an environment that is actively hostile to this individual? Either way, it's just something to consider based on personal observation/experience. It could be completely wrong, could be a bit of both. There's no harm in asking questions. * * * edit: to you comment below. I am suggesting that the depression itself (for example, in the case of a bipolar individual -- not in the case of major depression, which is a different thing altogether), could be a symptom not of a "disease" but rather a natural reaction to living in an environment that is toxic to him or her. In such an environment, it is perfectly natural for this individual to lose all drive, feel "worthless", and even break down mentally. The links between chronic stress and depression are well known. Robert Sapolsky has a great lecture on the biology of depression: https://youtu.be/NOAgplgTxfc https://youtu.be/NOAgplgTxfc (tl;dw: major depression physiologically looks very little like "sadness" and a hell of a lot like chronic stress (an over-active stress response) and does indeed fit the profile of a biological disease, often caused by early trauma. My question here is: have we built societies that are inherently traumatizing to individuals with particular behavioral phenotypes? Looking elsewhere, at societies and subcultures where these "disorders" are not as common or as debilitating to me suggests that there is at least some truth to this.)