Kenneth Nunn is a specialist in paediatric neuropsychiatry. He was Emeritus Consultant Child and Adolescent Psychiatrist at the Children's Hospital, Westmead, Sydney, Australia, and Senior Child and Adolescent Consultant in Justice Health, New South Wales. He was previously Professor of Child Psychiatry at the University of Newcastle, New South Wales. Tanya Hanstock is Doctor of Clinical and Health Psychology and Senior Clinical Psychologist at The Bipolar Program, Hunter New England Area Health Service, Newcastle, Australia. She is also Conjoint Senior Lecturer at the University of Newcastle and Adjunct Lecturer at the University of New England, Armidale, Australia. Bryan Lask is Emeritus Professor of Child and Adolescent Psychiatry at St George's, University of London, UK, Medical Adviser and Research Director at the Huntercombe Hospital Group, UK, and Visiting Professor at the Regional Eating Disorders Service, Ulleval University Hospital, Oslo, Norway.