Solitary confinement can have a powerfully detrimental effect on someone's identity and mental health - it has been called a form of torture. Claudia Hammond talks to ex political prisoners about their experiences and how they dealt with living in such inhumane conditions. She hears advice from Professor Craig Heaney who works with prisoners in Supermax prisons in the US and psychiatrist Professor David Alexander who has worked with many hostages.
In Japan hundreds of thousands of young people withdraw from society for years or even decades. They are known as hikikomori. Claudia Hammond travels to Tokyo to discover more about this mysterious condition and why it is so prevalent in Japan.
(Photo: Solitary Confinement. Credit: Getty Images.)