David M Clark is the Professor of Experimental Psychology at the University of Oxford. He is well-known for his pioneering work on the understanding and psychological treatment of anxiety disorders: especially panic disorder, social anxiety disorder, health anxiety and PTSD. Recently, he has also focused on how to disseminate effective psychological treatments within healthcare systems and is one of the architects of the English Improving Access to Psychological Therapies (IAPT) programme. Currently, the IAPT program treats around 560,000 people with depression or anxiety disorders each year and reports clinical outcomes on almost everyone. 2 in every 3 treated people reliably improve and 50% recover. David is the UK Government’s Clinical and Informatics Advisor for the program. He is a Fellow of the British Academy, the UK Academies of Medical Sciences and Social Sciences, the British Association of Behavioural Psychotherapies, ABCT, and APS. He is also a Founding Fellow of the Academy of Cognitive Therapy. He was made a Commander of the British Empire (CBE) for services to mental health in 2013.