Throughout Gothic fiction you will find numerous examples of characters with mental disorders, many of them written at a time when little was known about such conditions. Perhaps part of the attraction to works on the malfunctioning of the mind had to do with curiosity of a subject which was mysterious.
Feminist readings
A feminist reading into the theme of ‘madness’ in Gothic Lit might establish that the inability to be in control of one’s mind leaves the character powerless. Madness was then a device for depicting the powerlessness of women to men in male dominated society.
However, not all characters indicating mental disorders in Gothic are female. (see Roderick Usher in Poe’s The fall of the House of Usher or the narrator in Poe’s Telltale Heart who becomes obsessed with the old man’s eye.
Female characters exhibiting what was often termed as ‘hysteria’ were generally locked away in attics etc. so that they could be contained. It is the case in The Yellow Wallpaper by Charlotte Perkins Gilman published in The New England Magazine in 1892. The woman’s husband keeps her shut away in one room of the house as he claims that she is suffering from. He is himself a physician and therefore an authority on the subject of course!
‘A slight hysterical tendency,’ he says.
Shut away from the world and with no stimuli, she begins to obsess over the yellow wallpaper and eventually begins to see women behind it. She sees herself as one of these women. When the rental of the house is up she refuses to leave as she is afraid of the outside world and has developed an attachment to her yellow surroundings as a bird that has become cage bound even when it is allowed to fly. If reading this from a feminist angle then man has the power to control.
Then there is the intermingling of reality and delusion, just as Oates’ Goat Girl is an intermingling of animal and human, so does the women in this story become a blending into yellow wallpaper. The confines of domesticity if you like!
Aside from this there is this human fascination with the mind which I have discussed above. Much of the genre of horror is based on psychological fear of the unknown as opposed to blood guts and gore.
In Poe’s Fall of the House of Usher Roderick calls upon his old friend to comfort him from his suffering of malady which in today would be termed hypochondria, hyperesthesia and nervous anxiety! His sister is also suffering from some unknown illness and frequently enters trance like states. She would nowadays be described as cataleptic. A condition whereby the patient often suffers symptoms such as rigidity of the body, fixed limbs, and a slowing down of all body functions. A scientific explanation for her illness is much less alarming than the mysterious description in the text. The Victorians just loved to be frightened by such things.