mental treatment act 1930 mental treatment act 1930 the mental treatment act 1930 was an act of the parliament of the united kingdom permitting voluntary admission to, and outpatient treatment within, psychiatric hospitals. it also replaced the term "asylum" with "mental hospital". mental treatment act 1930act of parliamentparliament of the united kingdomlong titlean act to amend the lunacy acts, 1890 to 1922, and such of the provisions of the mental deficiency acts, 1913 to 1927, as relate to the constitution and organisation of the work of the board of control, the exercise of the powers of the board and the protection of persons putting those acts into operation.citation20 & 21 geo. 5. c. 23datesroyal assent10 july 1930other legislationrepealed bymental health act 1959status: repealed it was repealed by the mental health act 1959.