- the Mental Disease Ordinance Chapter 559 is the current legislation relating to mental health which is based on the concepts and attitudes to mental disorder that prevailed in 1873 when this Law was first enacted. Many changes have taken place since then and the need to revise the existing Ordinance has been recognized. Accordingly, the proposal made by Hon. Maithripala Sirisena, Minister of Health, to instruct the Legal Draftsman to draft new legislation for the purpose, was approved by the Cabinet.