“It’s a horrifying state – a very strange feeling. The sufferer feels like they are dead even if they don’t want to be,” Anders Helldén, clinical pharmacologist and nephrologist at Stockholm’s Karolinska Institute, told The Local.
Helldén and Thomas Lindén, a consultant in neurology and psychiatry at Gothenburg’s Sahlgrenska hospital, first made the connection between the drug and the syndrome in 2007, when they found two patients from different sides of the world suffering Cotard’s Syndrome after taking the household medicine acyclovir, most commonly marketed as Acivir, Acivirax, Cyclovir, Herpex, Xovir, Zovirax, or Zoral.
One of the patients was so severely affected that it wasn’t until after four hours of dialysis that she could explain “how utterly frightening her sense of being dead had been”.
“It was very fascinating, and a lot of people told us they were interested, but two cases were not enough to prove any kind of connection,” Helldén said. “Today, we’ve confirmed the connection and have ten, maybe eleven cases.”
The medicine is extremely common, with Helldén explaining that around 80 million people take it every day, usually in connection with curing herpes of the lips or genitals. The condition is extremely uncommon, however, with only 110 cases recorded since 1880, when French neurologist Jules Cotard first observed it. It is found mainly in patients with impaired renal function.
The condition, also known as the Cotard delusion, sees sufferers feeling such distance from their own body that they feel as though they are literally dead, neglecting personal hygiene, their well-being, and even reality. It usually comes with severe depression.
“It’s complicated, but we now have a sort of on/off switch for Cotard’s syndrome. When we put the sufferer on dialysis and remove all traces of the drug from the body, symptoms can disappear in a few hours,” said Helldén.
“Now it’s just a matter of improving our understanding and making further developments.”
The duo is now looking to further their research and is on the hunt for funding. They are in the middle of writing up their discoveries with the intention to publish as soon as possible.