Following a PhD at University of Oxford, and a Doctorate in Clinical Psychology at the Institute of Psychiatry, Kings College, London, Warren came to the University of Manchester where he is currently a Reader in Clinical Psychology. The focus of his research is psychological approaches to bipolar disorder, transdiagnostic interventions for mental health problems (e.g. A Transdiagnostic Approach to CBT using Method of Levels Therapy), and Perceptual Control Theory.