The Rest Test. What exactly is rest, are you getting enough and what's the best way to do it? A global investigation of rest needs your help to find out. Claudia Hammond talks to Dr Felicity Callard about why she wants to find out about the nation's resting habits. Arson costs the UK economy around £45 million every week. So why do people start fires and what can be done to change their behaviour? Professor Theresa Gannon discusses her research into the unique psychology of people who set fires and why her findings have helped her to develop a new treatment programme. Claudia also talks to Dr Lisa Cameron, the first clinical psychologist to become an MP. She talks about her plans for changing mental health and her psychological insights into the machinations of politics in the House.