Tim Leighton <back Tim is the Director of Professional Education and Research for the charity Action on Addiction. He oversees the charity’s Centre for Addiction Treatment Studies (CATS). He has worked in the field since 1985. He designed and launched the University of Bath Foundation Degree and BSc (Hons) in Addictions Counselling in 2004. Tim is a UKCP registered Cognitive Analytic Psychotherapist and an accredited trainer and supervisor. His current research interests are mechanisms of change in alcohol and drug rehabilitation programmes, and theory-based evaluation of treatment programmes.