This year has seen a series of so-called lone-wolf attacks that have killed hundreds of people around the world.
Some have been linked to the kind of violent ideology promoted by the Islamic State of Iraq and the Levant (ISIL, also known as ISIS). Others have not.
From Orlando to Nice to Munich, relatives of some of the attackers have come forward and talked about a history of mental illness.
But the role of mental health is often missing in the discussion about the possible motives for these mass killings.
So, is there a link between violence and mental health? And what are governments doing to deal with it?
Presenter: Sami Zeidan
Raj Persaud – Consultant psychiatrist and a Professor at Gresham College, London
Peter Yaro – Executive director of Basic Needs Ghana