In the Paris Review, a fascinating, dense, and heavily illustrated history of how we've depicted insanity through imagery, written by sociologist Andrew T. Scull, author of numerous books on madness, hysteria, and culture.
From the Paris Review:
Modern psychiatry seems determined to rob madness of its meanings, insisting that its depredations can be reduced to biology and nothing but biology. One must doubt it. The social and cultural dimensions of mental disorders, so indispensable a part of the story of madness and civilization over the centuries, are unlikely to melt away, or to prove no more than an epiphenomenal feature of so universal a feature of human existence. Madness indeed has its meanings, elusive and evanescent as our attempts to capture them have been.
Western culture throughout its long and tangled history provides us with a rich array of images, a remarkable set of windows into both popular and latterly professional beliefs about insanity.
"Madness and Meaning: Depictions of insanity through history" (Paris Review)