I see society collapsing as the root cause. It is happening in many ways but we have created a society that is increasingly incapable of raising strong, resilient, healthy, well-rounded people.
This includes the economic incentives for business and the metrics they use, but also many other aspects too. It is all related.
We are an ill species. We used to be improving, but we got a little too smart for ourselves and now we are headed backward.
The cause of each individual might seem different and personal, but I think that for the most part, it is more interpersonal.