Swedish pharmacologists have discovered a nasty modern paradox: cold sores might make you wish you were dead—but cold sore treatments might make you think you are dead.
It’s rare, but it happens. There exists a rare psychological disorder called Cotard’s syndrome, also known as walking-dead syndrome because its sufferers erroneously believe they are dead, decomposing, or missing key internal organs or body parts.
And in extremely rare cases, patients with no history of mental problems who use the drug acyclovir (sold under the trade name Zovirax) to treat cold sores, herpes, shingles or chicken pox, started demonstrating symptoms of Cotard’s.
According to a study published in the Journal of the Neurological Sciences, Swedish researchers uncovered a possible link between renal failure, acyclovir use and Cotard’s (which is not synonymous with saying “Cotard’s only inflicts renal-failure victims who take acyclovir”).
Researcher Anders Helldén from Stockholm’s Karolinska University Hospital mentioned the case of a Swedish woman who started showing Cotard’s symptoms after taking acyclovir to treat shingles: she went to the emergency room in a state of high anxiety because she strongly feared she was dead. After a few hours her symptoms alleviated enough that she decided she was alive after all—except for her left arm, which she insisted didn’t really belong to her. Yet within 24 hours of her hospital visit, all such delusions had completely vanished.
So what happened? Turns out that people suffering from Cotard’s tend also to have high levels of a chemical called CMMG in their bloodstreams. And CMMG is also one of the chemicals left over after acyclovir breaks down in the body. Helldén speculated that CMMG might constrict blood flow in the brain, which in turn might interfere with ordinary brain functions to the point of delusion.
For acyclovir users who develop Cotard’s symptoms, the cure is as simple as weaning off the drug. As for those unfortunate people who suffer from Cotard’s syndrome without acyclovir—well, thus far medical science has not yet found a cure, but the discovery of the CMMG/Cotard’s connection might prove the first step on the road leading to one.