Prof. Derek Bolton is Professor of Philosophy & Psychopathology at the Institute of Psychiatry, Kings' College London and Honorary Consultant Clinical Psychologist at the South London & Maudsley NHS Foundation Trust. He has worked on causal explanation in psychology and psychiatry (Bolton D. & Hill J. Mind, Meaning, and Mental Disorder: The Nature of Causal Explanation in Psychology and Psychiatry. 2e. Oxford University Press, 2004) and has been PI on several RCTs in behaviour therapy and cognitive behaviour therapy. His latest book is What is mental disorder? An essay in philosophy, science and values (2008) is published by Oxford University Press).