I can't think of a much bigger reason out there of why so many are getting depressed than humanity's disconnection from nature and from each other. I know that for myself, the last few years has brought much heartache pretty much because of this disconnection, nothing else even comes close to being the cause. I live in a large Australian city and I just don't sync with 99.99% of the people around here, especially people around my age (early 20s).