I watched a program about forensic anthropologists who were trying to discover the remains of a 17 century artist, since he disappeared without a trace. The painter was quite prolific, but had very anti-social behavior and was always wanted by authorities. From what was detected, it appears that many of the painters had lead poisoning, which seemed to answer the question about their erratic/violent/depressed behavior. Van Gogh, Michelangelo may have also been victims of that poisoning.
We are lucky to live in more informed times.....just before we kill our planet.
I hope we can reverse at least some of the damage before long.