>Your depression may well have felt like extreme sadness or grief. Why do you think your individual experience transfers to all other people with depression?

I'm not necessarily saying it does. There may be different types of depression. However I'm saying that this particular type of depression that I experienced definitely was extreme sadness, and it's pretty obvious that that is the case if you have experienced it. It's like saying that a colour is a slightly darker shade of blue.

>This is called "reactive depression". Do you have any real numbers, or are you just going by the people who you know

No, it is just an observation of people I know who have had depression.