Actually that makes sense. studies show epigenetic gene expression and its connections to depression. Conflicts like world war 2, that happened 80 years ago could be affecting us today. Abuse our parents, grandparents, great grandparents had to deal with could be the reason why we are more depressed.
I come from a family who lived in okinawa in 1945, my grandparents was part of children who were made to fight/work by the japanese imperial navy. They came here to the US for a better life. It was better but that didn’t change the fact that my grandparents went through that.
My entire family (3 generations) suffers from depression. My kids have never been abused so they don’t have depression but they are one stressful event away from being depressed.