It’s the stuff that makes fans of “The Walking Dead” and other zombie enthusiasts keep coming back for more – only it has happened in real life to writer Esme Weijun Wang, who for nearly two months thought she was dead.

On Nov. 5, 2013, Wang started to believe she was dead, following weeks of feeling more and more fractured and losing grip on reality and her own identity. Thinking of it as the early symptoms of psychosis, she sought self-help, reorganized her workspace, and reexamined herself being a writer.

Wang had her episode:she drifted in and out of consciousness for about four hours during a flight from London to San Francisco. "I was convinced that I had died on that flight,” the now 32-year-old recalled, believing her husband and their dog were also dead and deeming her waking moment as one spent in the afterlife.

In her essay, "Perdition Days," Wang relived the experience, in which she felt was “some kind of hell” where she “was on fire inside.”

What was afflicting Wang has a name: Cotard syndrome, where the patient believes she is either dead or nonexistent. In the 1880s, French neurologist Jules Cotard first described the condition as a kind of depression marked by anxious melancholia and deluded thoughts about one’s body.

In a 43-year-old woman’s case documented in 1880, the patient believed “she has no brain, no nerves, no chest, no stomach, no intestines,” only a decomposing body’s skin and bones.

Dubbed as “walking corpse syndrome,” Cotard syndrome is not separately classified in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders. However, doctors consider it a real disease – the belief of being dead leading to extreme depression, anxiety, and suicidal behavior.

Mexican psychiatrist Jesus Ramirez-Bermudez has seen Cotard’s syndrome patients, and as early as his days as a medical student, he had encountered schizophrenia-diagnosed patients saying they were already dead.

After his own research, Dr. Ramirez-Bermudez concluded those were cases of Cotard syndrome, and he had since treated 14 patients using a combination of drugs and psychotherapy.

It is not yet clear what causes the illness. In Wang’s case, she was diagnosed with some bipolar-type schizo-affective condition in 2013, but she thought her Lyme disease – long left untreated – may have led to the delusion.

While no case of Cotard has been associated with Lyme disease, Dr. Ramirez-Bermudez previously encountered a related case, where the delusion may have manifested from a brain inflammation caused by a virus.

Lyme disease, however, is caused by the bacterium Borrelia burgdorferi and is acquired by humans via infected blacklegged tick bite. Fever, headache, fatigue, and a distinct skin rash are some of its usual symptoms.

Wang’s own episode was resolved before she was diagnosed with Lyme infection, and the recovery did not follow any specific treatment – the delusion just “lifted completely without fanfare” after less than two months when it started.

The condition could last days or weeks, with a number of patients exhibiting chronic Cotard syndrome from months to years. The original recorded case of it was chronic, and the patient was eventually killed by starvation.

Photo: Lloyd Morgan | Flickr