The Manchurian Candidate (1962), the most famous cinematographic example of 'brainwashing.'
Brainwash (someone): to force (a person) to obey, conform, confess etc by putting enormous psychological pressure on them. To control a person's thinking through psychological or physical torture, disorientation, or coercion. As a verb, the Oxford English Dictionary first finds this familiar usage appearing in Publisher's Weekly in 1951 as in "the communists are 'brain washing' the minds of the educated Chinese". As a noun, however, the phrase appears to mean an instance of brainwashing - literally. As, for instance, a usage in the Manchester Guardian in 1950: "A school teacher who was summoned to a 'brain-wash' before a large audience partly consisting of his pupils."