De Havilland famously remarked that it was harder to play 'nice' girls and is most often associated with the Melanies and Maid Marians. Snake Pit proves she also could carry off the darker side of humanity with great aplomb. Single handedly, she drags you through the ups and downs of the various emotions of her changing illness - bemused, frightened, generous - without effort and always believably. Despite a few caricatures of the 'insane', and a slightly underwhelming (indifferent?) Leo Genn as her doctor, Snake Pit is one of the great mental illness films.