“A tense environment and a good villain” are the perfect ingredients for mass hysteria, according to psychologist and epidemiologist Professor Simon Wessley. It’s a phrase so toxic, it was removed from the diagnostic manual in the late 1960s. But as neurologist and mystery illness expert Suzanne O’Sullivan explains, “We are all vulnerable. We just need to meet the right circumstance.”

In the penultimate episode of Havana Helmet Club, Jennifer Forde and Sam Bungey investigate high-profile cases of mass hysteria – now known as mass psychogenic illness or conversion disorder - for clues about Havana Syndrome. Could it be the solution to the puzzle, or a way for the CIA to dig themselves out of a hole?

Credits

Havana Helmet Club is a Yarn production for Radio 4 and BBC Sounds.