• Cotton developed a dangerous theory about mental illness, one that turned his hospital into a house of horrors. Cotton began to suspect that all mental illness was caused by bodily infections, and that the only way to cure the patient was to remove the offending infection. In 1917, he began removing his patients' teeth, even in cases where X-Rays showed no evidence of infection. He soon moved on to other body parts: gall bladder, stomachs, ovaries, testicles, tracts of colon, uteruses.