Claudia Hammond talks to Henrietta Bowden-Jones who runs the only NHS clinic for problem gamblers. Based in Central London it offers help to problem gamblers across the country. Treatment is mainly group based cognitive behavioural therapy. As many as 8 out of 10 patients, who are mostly men, have stopped gambling after 8 weeks of treatment at the clinic. But should more similar treatment centres be set up across the country for an addiction which often remains hidden? Also in the programme, Christian Jarrett joins Claudia to discuss why owls and larks could soon be joined by two new types of people based on how energetic they feel. Also, psychologist Stephen Reicher questions some of Stanley Milgram's conclusions about his infamous obedience experiments of the 1960s. And why if you're depressed you may find you lose your gut instinct.