It's a model. There are plenty of other models for the symptoms classified under clinical depression, human suffering is not a new thing that people just starte

It's a model. There are plenty of other models for the symptoms classified under clinical depression, human suffering is not a new thing that people just started trying to solve in the last century. Depression has some stigma attached to it, and big pharma profits a lot from it. The model and its treatments do help a lot of people, but there are an equal or greater number that they don't help. As a model it's pretty meh in my opinion but it's the best thing that modern science has come up with.