I just finished the book, The Sleeping Beauties: And Other Stories of Mystery Illness by Suzanne O'Sullivan. This should be required reading for all providers of medical care.
This book talks about culture-bound psychosomatic illnesses from around the World. What I found fascinating, was how these mass functional illnesses, are so linked to culture and the final outcomes (improvement or worsening) of the people suffering are so dependent on their society.
How we relate with our patients, how we frame what they have, the way we validate their symptoms yet move towards acceptability of normalcy makes a massive difference in recovery.
Functional illnesses are very tricky to maneuver with patients. I think this book provides great context for all medical providers.