John Teasdale has worked as a research scientist, funded by the Medical Research Council, first in the Department of Psychiatry, University of Oxford, then in the Cognition and Brain Sciences Unit, Cambridge. His research has investigated basic psychological processes and the application of that understanding to the relief of emotional disorders. For many years, this research involved the exploration of cognitive approaches to understanding and treating major depression, and he was one of the pioneers of cognitive therapy research in the United Kingdom. More recently, the findings of earlier research have been applied to the development and evaluation of mindfulness-based cognitive therapy.
He has received a Distinguished Scientist Award from the American Psychological Association, and has been elected Fellow of both the British Academy and the Academy of Medical Sciences. He is currently retired, pursuing personal interests in practising and teaching meditation and mindfulness training.