Just as Robert E. Howard’s take on prehistory was closer to the truth than the one promulgated by archaeologists in the past few decades, H.P. Lovecraft’s views on insanity were more realistic than the common ones in American popular culture – where people are thought to be driven insane by trauma, where your mum and dad fuck you up by their actions, rather than their genes. Lovecraft worried about hereditary taints ( like being descended from from an ape or the Deep Ones), rather than experiencing poor toilet training or ‘poverty’ that entails richer material circumstances than those of ancient kings.
Lovecraft’s personal experience may have shaped his views: both of his parents died in the same asylum. He thought the truth would drive a man crazy, but maybe it was the other way around.