Body integrity dysphoria is an extremely rare condition, in which people crave cutting off their healthy limb (especially an arm or leg) because they feel a mismatch between their mental and physical image.
In 1999, two men pleaded successfully with a Scottish surgeon to have their lower legs amputated. A quack doctor in the USA was indicted for murder after carrying out leg amputations on healthy men, who both died of gangrene.
Suicidal urges have been reduced in those who have the surgery performed.