Psychologists’ advice is that play is beneficial for children developmentally and socially. In this Christmas episode of All in the Mind Claudia visits the Play Well exhibition at Wellcome Collection which looks at the significance of play in childhood and across society as a way of learning, expressing emotions and building empathy. Claudia’s joined at the exhibition by play experts Maia and Rachel.

Children in the UK have written letters to Father Christmas since Victorian times and Dr Sian Pooley at the University of Oxford shows how they reveal the history of play.

LEGO Professor of Play Paul Ramchandani at the University of Cambridge researches the developmental benefits for children and looks at how fathers play with their children.

And how do you get children off the computer and playing outside? Helen Dodd, Professor of Child Psychology at Reading Univesity, and Dr Pete Etchells, Reader in Psychology and Science Communication at Bath Spa University, look at the evidence and ask if a balance can be achieved.

Pain has long been recognised as something of an enigma by scientists and clinicians. It's both a measurable physiological process, as well as deeply personal and subjective. Claudia Hammond meets scientists attending the British Neuroscience Association's Christmas symposium on pain and the brain.

She talks to the so-called "queen of pain", Professor Irene Tracey of Oxford University, about how research into acute and chronic pain is being addressed. We hear from Professor Ulrike Bingel about the positive and negative effects of expectation and anxiety on painful symptoms, and how this could be harnessed to enhance the power of drug treatments and reduce side effects.

Professor Tamar Makin of University College London reveals some of the latest insights into the mysterious pain associated with missing limbs and wonders if we've been getting the thinking on phantom limb pain all wrong.

And why are some kinds of pain - after exercising say, almost enjoyable? Professor Siri Leknes of Oslo University discusses the curious relationship between pain and pleasure.

A recent poll of junior lawyers suggested that 93% of participants experienced distress in the last month and 19% had felt unable to cope. Those across the legal profession are experiencing higher than average levels of stress, anxiety and alcohol abuse. Can the profession adapt to openly accommodate wellbeing to balance the demands of the job? Claudia Hammond talks to Emma Jones, Senior Lecturer in Law at the Open University who is now conducting research with the charity LawCare on mental health in the legal profession, and Alex McBride, who’s a criminal barrister turned author.

We all know that some of us are more sociable than others, depending on our personalities, experiences and the situations we find ourselves in. But could the microbes in our gut also play a part? John Cryan of the APG Microbiome Centre in Cork discusses his latest observations across species and in humans.

Three quarters of mental health problems first occur before we reach our mid-20s. Yet much of the research is done with adults. Dame Til Wykes, Professor of Clinical Psychology & Rehabilitation at Kings College London, discusses a new initiative - the young people mental health advisory group - to ensure the best possible research is being carried out through liaison with a group of teenagers who have experienced mental health difficulties themselves.

Producer Adrian Washbourne

The Wounded Healer, also known as Dr Ahmed Hankir, Academic Clinical Fellow in Psychiatry at Kings College London, tours the world talking about his experience of mental ill health and attacking stigma. But how does his lived experience impact his clinical practice? Joining Claudia and Ahmed in the studio to discuss the issues is Dr Sri Kalidindi,, consultant rehabilitation psychiatrist at the South London and Maudsley NHS Foundation Trust.

Technology companies are developing artificial intelligence that can detect your mood. They are doing this by reading facial expressions but is this too simplistic an approach? Lisa Feldman Barrett at North Eastern University in the US questions whether the psychological research is being interpreted in the right way. Gary McKeown, a psychologist from Queens University Belfast, joins the discussion.

Studio guest is Professor Catherine Loveday from the University of Westminster.

Acceptance and commitment therapy is an evolving talking therapy that is being used to address anxiety and depression. Rather than challenging negative thoughts, patients are trained to embrace them, Claudia Hammond hears how it's now being trialled for the psychological challenges that come with a number of physical conditions from muscular dystrophy to cancer.

We're at the culmination of the Million Minds tour - an attempt to reclaim the world record for the largest mental health lesson, which draws together psychologists, top performers and school children, aiming to break the teenage stigma surrounding mental health issues.

And with more financial transactions taking place online that ever before, can our digital footprint accurately reveal traits of our personality?

Claudia Hammond's guest is psychologist Prof Daryl O'Connor from Leeds University

Producer: Adrian Washbourne

The National Gallery is launching a new tour with the help of young people from the McPinn Foundation challenging stereotypes in mental health. The tour focuses on works of art which confront commonly held myths. Claudia meets Lucy who was diagnosed with anorexia at 13 and Helen Fisher from the Institute of Psychiatry , Psychology & Neuroscience, King's College London, Kings College, to see their favourite exhibits including “An Experiment on a Bird in the Air Pump” by Joseph Wright 'of Derby' and “The Vision of the Blessed Gabriele” by Carlo Crivelli. A magnificent domed room which hosted daily piano concerts during the Second World War and survived the bombing demonstrates the resilience often felt by people recovering from mental ill health. The tour is available for free until 10th April 2020 via smartphones. (tiny.cc/ngmentalhealth)

Studio guest Mathijs Lucassen of the Open University discusses his latest research on LGBT teenagers and mental health.

Plus, most people are used to the idea that as we get older there is a diminishing of our abilities, but Professor Roger Kreutz of Memphis University in his book “Changing Minds” demonstrates that language is one skill that can just get better. And with the aim of improving brain health Dr Alastair Noyce and colleagues recently launched a European report which says “Time Matters”.

Why do we have a strong desire to own things? Psychologist Professor Bruce Hood, author of a new book Possessed, and artist Hannah Scott, whose installation All this Stuff is Killing Me addresses our desire to acquire, discuss why we want more than we need and the extent to which we are controlled by our possessions.

Cognitive behavioural therapy is one of the most effective treatments for depression but it only works for 45% of patients, so success is not guaranteed. Claudia hears from Filippo Queirazza of Glasgow University who's been using brain imaging techniques to predict an individual's likely success with the therapy. This could dramatically increase the odds of correct treatment for a patient.

Talking to strangers is something many feel anxious about or reluctant to do but could it be good for your state of mind? Social psychologist Gillian Sandstrom of Essex University discusses her latest research: seemingly inconsequential conversations with strangers can have a surprisingly beneficial effect on mood and well being.

Producer: Adrian Washbourne

Stress at work. Adam Kay, an ex junior doctor turned author and stand up performer, published the diary of his time of working in the NHS. It struck a chord and sold over a million copies in the UK. It's a story of working under duress, long hours and limited resources which many people can identify with and he delivered over 1200 babies in those circumstances. Gail Kinman is Professor of Occupational Health Psychology at the University of Bedfordshire. Gail's worked with doctors, nurses, prison officers and social workers. Together with presenter Claudia Hammond and an audience they look at what stress is, how people burn out as well as how to spot the warning signs. What can individuals do to protect themselves and what are the responsibilities of the organisations they work for?

Claudia finds out about a new approach to childhood anxiety - an intervention for anxious parents to help them manage their own fears and how they impact their parenting. She meets parents on the course run by Sussex Partnership NHS Trust and talks to Professor Sam Cartwright-Hatton from Sussex University who explains what can be done to help prevent mums and dads transmit their own fears to their children. Pamela Qualter from Manchester University discusses new findings on what predicts mental well-being in children. After several suicides in St Ives in Cambridgeshire, residents decided to prioritise mental health and make it a place where people are encouraged to open up about their feelings in the pub, barbers and even at Pilates. Olivia Crellin reports. Also in the programme, research has found that people who live in areas of high air pollution experience more psychosis. But why and what might be the mechanism? Pamela Qualter discusses.

Claudia talks to Professor Steven Rogelberg about the science of meetings. Should we get rid of them altogether? Or what can we do to improve them? Also, how can we help those with dementia sleep better? Professor Susan McCurry and Dr Alpar Lazar discuss the latest research on sleep-regulation for people with dementia. And how good are we at estimating the size of our bodies? Claudia visits Birkbeck, University of London where Renata Sadibolova and Professor Matthew Longo conduct an experiment to see how good Claudia is at estimating her body size.