October is prime time to indulge in our creepiest pastimes. We carve pumpkins into scary faces and decorate our homes with ghastly supernatural beings. We break out scary movies and visit haunted houses just to revel in the frightening, the horrifying, the unknown.

One of the most pervasive examples of our fondness for the enigmatic is society’s fascination with possession. There have been countless stories devoted to possession. Whether it’s a gruesome film devoted to demonic possession (à la The Exorcist), or the stories detailing the chaos and possessions caused by witchcraft in Salem, Mass., it’s clear pop culture loves possession.

For most modern people, the idea that there were actually witches in Salem, or that people in history have been possessed by demons is downright ludicrous. It’s impossible to deny the large number of eyewitness testimonies in both cases, though, and one is left with the explanation that either, A) Everyone was flat out lying, or B) These victims of “possession” were really exhibiting symptoms like convulsions, contortions, and bursts of strange sounds.

Such unusual behavior seemed, at the time, to defy all rational explanation. Thanks to advancements in medical technology, research, and psychological understanding, several modern day scientists have suggested possible medical explanations for the bizarre behavior detailed in historical accounts of possession. There is no solid answer for what really happened in Salem, or the number of towns that claim to have dealt with possessions, but some of the theories are quite possibly as fascinating as the idea of a true possession.

Ergot poisoning

In most cases of possession — whether witchcraft caused it or not — the afflicted share certain physical aspects. Convulsions, (or “fits), fainting, changes in vocal and facial structure, the sudden appearance of skin lesions and injuries, and the loss of personality or memory are all common in the accounts of possession throughout history. Before we had knowledge of conditions that could reasonably cause such behavior, like during the Salem witchcraft trials, these things would be viewed as sinister, a sure mark of dark happenings. Hundreds of years later, though, scientists have suggested several explanations for the events — the first of which is ergot poisoning, or ergotism.

Caused by the ingestion of fungi belonging to the genus Claviceps, which often grew on rye in cool, damp conditions. Rye bread was a dietary staple in the colonies at the time, and historians have recognized that New England was unusually cool in 1690, 1691, and 1692.

The victims of "possession" because of witchcraft were reported to convulse and twitch at trials. wikipedia public domain

In 1976, ergot poisoning was proposed as the cause of the witch persecution in Salem for the first time by Linda R. Caporeal, a graduate student at the University of California at Santa Barbara. Caporeal argues that the symptoms displayed by those thought to be bewitched were quite typical of ergotism, including convulsions and mental effects like mania or psychosis. She even added that any claims of visual hallucination were very similar to those produced by the hallucinogen LSD, which is a chemical derivative of ergot.

The theory has been both dismissed and praised, with critics noting the absence of other ergot symptoms in testimonials, and that an explanation of poisoning does not take into account the complex social and psychological effects of the culture at the time. Some researchers were skeptical of the theory also because symptoms of possession and bewitchment occurred on an individual basis, rather than a house-by-house basis, which would be the case if a family’s food supply was poisoned. Despite these objections, ergotism is still cited by some historians and scientists as a possible reason for the “supernatural’ events in Salem.

Mental and Physical Disorders

Though events in Salem must be scrutinized under a religious and historical lens, there are some isolated cases of “demonic possession” that do not share the sociological importance of the Salem witchcraft crisis. These cases seem to have arisen out of nowhere, and some of them occurred within the last century — a time when modern science and diagnoses should have been able to explain any disturbing behavior.

Several mental disorders have been associated with symptoms of possession, including Tourette's syndrome and schizophrenia because of the erratic and psychotic behavior often reported in victims of possession. Possession is most usually linked to dissociative identity disorder, however. About 29 percent of those with the disorder, often called split personality, are reported to identify themselves as demons. A plethora of mental and mood disorders could cause the psychological symptoms of possession, but what about the times witnesses claim to see physical symptoms?

Dr. Kathleen Sands presented a lecture at The College of Physicians of Philadelphia, called "Demonic Possession and Exorcism: Medical Explainations?," that suggested several possible causes for a few physical manifestations of possession. Some cases report words appearing on the skin of possession victims, something Sands attributes to dermatographic urticaria, a disorder that translates to “writing on the skin.” Those with the disease can stroke or press the skin to create red, welt-like lines that could appear quite worrying to a witness with no knowledge of the condition.

A condition like dermatographia could appear as the work of a sinister being, but it was really just the condition that made the markings possible. Wikipedia Public Domain

A second classic symptom of demonic possession is that of foreign objects manifesting in the body or being thrown up. Sands points to a disorder known as allotriphagy as a possible explanation for this — admittedly freaky — behavior. An “unnatural desire for abnormal foods,” allotriophagy can lead to the vomiting up of unnatural objects like coins, stones, and glass.

There may never be a concrete medical explanation for the events detailed in court testimonials and diaries that describe occasions of possession. Whether anyone ever does determine what happened in Salem, or in any other case of “supernatural” sickness is uncertain, but it’s pretty easy to see we won’t stop wondering anytime soon.