Lobotomy, aka "lobectomy", is a largely discredited neurosurgical procedure that seeks to cure mental illnesses of various types through the severing of nerves in the frontal cortex of the human brain. This may be accomplished in either of two ways - though drilling a hole in the skull through which is placed an instrument to sever nerves through cutting or crushing, or by inserting a sharp instrument through the back of the eyeball and then moving it diagonally to sever nerves.
In 1848, the miner Phineas Gage had a tamping rod, used to place dynamite in holes for excavations, blown through his forehead by accident. Remarkably, he lived, although doctors and co-workers noted that while before the incident Gage had been a calm person, he now was rude and vulgar. This gave some doctors the idea of treating mental illness by causing similar damage to the frontal lobes.
Dr. Egas Moniz
Dr. Egas Moniz is popularly known as the creator of psychosurgery and the developer of lobotomy, though there is some question as to whether or not this image is valid. His inspirations were psychosurgical interventions done by the Swiss doctor Gottlieb Burckhardt, who claimed a 50% success rate through neurosurgery on schizophrenics, as well as the research done by Carlyle Jacobsen of Yale who found that artificially inducing damage to the frontal lobes of chimps caused them to become calmer and more even-tempered. He performed the first lobotomy at a hospital in his native Portugal in 1935; in 1949, he was awarded a Nobel Prize for the development of the procedure.
It gets worse
In 1936, the neuroscientist Dr. Walter Freeman brought lobotomy to America, and made it a special obsession of his. Dissatisfied with the intensive surgical preparation and resources required to work on the brain, and seeking to make the procedure more available to more patients, he pioneered in 1946 the transorbital lobotomy, in which he first stunned the patient with electroshock, then tapped a thin icepick-like instrument (the leucotome) through the back of the patient's eye socket with a hammer and then moved the leucotome up and down to sever the nerves in the frontal cortex. Since he viewed this as a "closed operation" during which no contamination could get into the surgery, he treated it as an outpatient procedure, some accounts having him doing the lobotomy in his own office. Indeed, his falling out over transorbital lobotomy with his partner Watts was over such a case, during which Watts returned to the office only to find Freeman with a sedated patient with leucotomes sticking out from his eyes and Freeman requesting Watts hold up a backdrop so Freeman could take his usual pictures of the procedure. (He claimed that he took pictures of the operations as a record, though it seems more as if he wanted souvenirs.)
For god's sake, why?
From the range of reasons given by doctors for using lobotomy, from severe depression to backache, it's rather obvious that the justification for using lobotomy was loose. Indeed, most neurosurgeons worried less about the why of the procedure than the how and to whom. That said, some justifications were put forward for lobotomy, from the idea that destroying the connection with the frontal lobes freed a patient from an overbearing superego, to the concept that cutting nerves severed "ruts" of nerves around which delusions cycled like cars on a racetrack. In the end, it was partially the lack of knowledge about what exactly happened during the lobotomy that ended the procedure, as well as the developments of electroshock therapy and more effective pharmaceutical treatments for mental illness.