Which field did Sigmund Freud win the Nobel Prize in?

The Austrian neurologist and founder of psychoanalysis Sigmund Freud (1856-1939) was nominated for the Nobel Medicine Prize for the first time in 1915 by US neurologist William Alanson White, Freud went on to be nominated for a Nobel a total of 13 times until 1938, one year before his death in London. Freud has never received the Nobel Prize.