In a special edition, Claudia Hammond talks to the father of Positive Psychology, Professor Martin Seligman, about why optimism is not only good for your health, but could also help you live longer. Claudia visits a school that has introduced happiness lessons with some surprising results. And we hear from Dr Julie Norem about why, for some of us, a more pessimistic approach might be the winning strategy. The programme also hears from listeners regarding the previous week's programme on the side effects of anti-psychotic medication for women.