A large component of our melancholy moods is a sadness and horror over how fragile we are. Our bodies, always betrayers in the end, are surprisingly strong, but still vulnerable to any number of unforeseeable events that could attack us from without or within. Our emotional states, too, are susceptible to hurt and trauma. A common way we describe heartbreak or shock from a devastating event is that we feel “shattered.” DixonBaxi Shattered Glass

The “glass delusion,” a common psychiatric malady of the 14th-16th centuries, takes that fragile, brittle feeling to extremes. King Charles VI of France, who may have suffered from what we now call schizophrenia, was one of the first people to manifest this particular delusion.

Someone experiencing the glass delusion literally thinks their body is made of glass, and may break against the hard, unyeilding obejcts most of us don’t give a second thought. The world, already dangerous and imposes, closes in for those with the glass delusion. Every edge is a threat, a fall could be the end.

Now, while many of our populace deal with a wide smorgasbord of delusions (which is a spectrum anyway, mentally sane and healthy people also suffer from false beliefs or thoughts, the issue comes when it varies too far from reality or societal conventions) the glass delusion has dissipated, but it’s still around.

Netherlands psychiatrist Andy Lameijn says he’s dealt with a recent case. “It was an authentic case – it was unmistakable that it was a glass delusion,” he said of his patient. This discovery led him to uncover a handful more since the reports of the glass delusion died out centuries ago. In the 1930s a woman was admitted to a Dutch psychiatric hospital believing her legs and back were made of glass.

In a slight variation of the glass delusion, but still relevant, 19th century Princess Alexandra of Bavaria was under the impression she had swallowed a glass piano as a child, and had to move carefully to not break it.

It’s an odd delusion, but like most delusions, it’s a vivid metaphor for the fears and anxieties many of us experience, a waking nightmare.