What is New in the ICD-11 on Mental, Behavioural or Neurodevelopmental Disorders Structure of Chapter 06 The hierarchy of Chapter 06 comprises: 1st level - Broad category of disease/disorder type 2nd level - Specific disease/disorder type 3rd level - Further specificity of disease/disorder type The Rationale for Chapter 06 Since the time of the Advisory Group’s initial appointment in 2007, the overall linear structure of the proposed mental, behavioural, or neurodevelopmental disorders chapter for ICD–11 has been the subject of substantive and comprehensive discussions by the Topic Disorders Advisory Group for Mental Health, as well as extensive interactions with the American Psychiatric Association concerning the just-published Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) (1), from the time of the Advisory Group’s initial appointment in 2007. The architecture of diagnostic classification of mental and behavioural disorders is an issue that has rec