The main focus of his research has been on the ways in which patients’ beliefs about their illness and treatment affect self-regulation and self-management across a wide range of physical health problems. An increasing part of this work is concerned with understanding the reasons underlying non-adherence to treatment, and in developing effective interventions for improving use of medicines and other recommended treatments. This work has also resulted in the development of widely used measures and cognitively-based interventions, which have been shown to be effective in improving adherence to treatment, recovery and quality of life.