One in six people around the world now say they feel lonely.

The World Health Organisation has termed loneliness a global health risk, saying the lonely are 30 percent more likely to die young - similar to the risks of smoking or obesity.

And it's taking a huge economic toll too - the cost to the US alone is estimated at $406 billion.

So why is this happening in the internet age of social media? And what can be done to address the problem?

Joining Juliet Mann on this edition of The Agenda are Elyakim Kislev from the School of Public Policy and Governance at The Hebrew University, Danny Dorling, Professor at Oxford University's School of Geography and the Environment and Pan Wang, Associate Professor in Chinese and Asian studies at the University of New South Wales.

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