1. Department of Gastroenterology, RAH Paisley, Paisley, UK,
2. Institute of Health and Wellbeing, University of Glasgow, Lilybank Gardens, Glasgow, UK,
3. Department of Psychiatry, Stobhill Hospital, Glasgow, UK,
4. School of Psychology, University of Glasgow, Glasgow, UK, and
5. School of Health Sciences, Queen Margaret University, Queen Margaret Dr, Musselburgh, UK