Was mass hysteria behind the mysterious case of 227 middle school students fainting last fall?

On September 23, 2022, 12-year-old Esmeralda walked out of the girls' bathroom at her middle school in Tapachula, Mexico, and fainted. Her best friend Diala came out behind her and also fainted.

Over the next hour, nine other girls and one boy at the Federal 1 public secondary school would spontaneously collapse in their classrooms, in the bathroom, and in the school's courtyard. Another 22 students would report other unusual symptoms like vomiting and headaches.

Esmeralda's mom, Gladys, got a text message from her niece, Esmeralda's cousin, telling her to come to the school immediately. She found Esmeralda lying on the pavement in the school's central courtyard, unable to speak or stand. Diala was slumped beside her. A cluster of other sick children lay on their backs.

"Esmeralda fainted and started convulsing on the ground," Diala said later. "I didn't expect to faint too, but then I woke up on the ground. I couldn't breathe right, it was really fast, and my eyes were red."

Several of the affected students reported smelling something smoky — Esmeralda said it reminded her of the smell of leaves burning up in the mountains — leading to suspicion marijuana was involved. But drug tests later came up negative. Several students also remembered seeing a powder in the bathroom that had a distinct, mustard-like hue. School administrators later turned up a sandwich bag with chicken soup base and a toxicology report came up clean for drugs.

At the hospital, doctors concluded Esmeralda and the others had suffered a panic attack. By the next morning, all of the children appeared to have fully recovered. Classes resumed the next week.

Two weeks later, on October 7, at a middle school in Bochil, a rural pueblo 150 miles from Tapachula at the northern edge of the Mexican state of Chiapas, at least 68 children fainted, vomited, or became disoriented. Dozens were hospitalized. An affected girl told a reporter from the magazine Gatopardo that her mouth felt like it was "crawling with ants." This time, tests found traces of cocaine in four of the affected students.

Four days after that, on October 11, there was a second incident at Federal 1 in Tapachula; this time, 18 children — again, mostly girls — fainted.

Once again, Gladys got a frantic text and rushed to the school. She found her daughter walking and talking normally. But when Esmerelda went back inside to use the girls' bathroom, she again smelled the strange burning odor and thought she saw blood. Through a cloud of dizziness, she made it back outside. "Mami I don't feel good," she told Gladys, and fainted.

Yet again, within twelve hours, Esmeralda was back to normal.

But this time, the school shut down while administrators puzzled over what to do next. A team of canines swept the halls, searching for drugs. None were found.

Over the next two months, episodes of mass fainting were reported in at least six middle schools in four Mexican states, hundreds of miles apart, affecting 227 children, most of them girls. Several students were sick for days or weeks.

Mexican President Andrés Manuel Lopez Obrador began including regular updates on the government's investigation into the fainting episodes in his daily press conferences.

But Gladys and the other parents felt they were getting no closer to an answer.

The theories

Gladys didn't buy the doctors' verdict that Esmerelda had suffered a panic attack.

Like other parents, she worried her daughter had been drugged. During the first hospital visit, the family had paid extra for blood tests for marijuana, cocaine, opioids, methamphetamine, and other amphetamines. The tests cost 350 pesos, or around eighteen dollars. It was a hefty expense.

The tests all came up negative, but Gladys remained skeptical. "It's possible there's something going on at the school and they don't want us to find out," she said.

She later ordered a second test, from a better resourced and more expensive lab in Mexico City. Months passed and the results never arrived.

A diverse set of theories was floated on social media and in the Mexican press: fertilizer poisoning, a rare bacterial illness, "probable smoke inhalation." An article in El Pais, a Spanish paper, posited an "unknown substance" could have been hiding in water sources. Other news sites mentioned a possible gas leak.

In time, the consensus mostly settled around drugs. The episodes were evidence of a rise in adolescent drug use, or, even more frightening, of a twisted play by drug cartels.

Proof of this, such as it was, mostly came down to the fact that the first episodes had occurred in Chiapas — a well-worn path at the southern edge of Mexico for drug and migrant smugglers heading north from Central America. The cartel theory was further fueled in mid-October, when investigators in Bochil announced they were looking for a man with a large tattoo who was seen hanging around the school on the day of the fainting episodes.

Luis Villagrán, a prominent migrant advocate in Tapachula who happened to have nieces enrolled at Federal 1, said the episodes could be part of a cartel initiation ritual, where teen-aged recruits would be tasked with drugging their peers to prove their loyalty.

While the majority of the parents avoided the press, Gladys agreed to multiple interviews.

She was incensed that Esmeralda and the others were being vilified, and that investigators were dragging their feet and banking on the public simply moving on. "They need to do something, because what if a child dies?"

If Esmeralda and her cousins bristled at this, Gladys would tell them: "Look at the news that's coming out and how they're saying you were the bad guys!"

'Putting a lid on the truth'

After the fainting episodes became national news, I was among a throng of journalists who traveled down to Tapachula from Mexico City. Journalists packed into the sidewalk in front of Federal 1, which is located in a quiet residential neighborhood near the center of town.

One parent, who identified herself only as Susanna because she worried her son would be targeted in retaliation for her speaking out, said she believed drugs were involved, most likely brought in by the adolescents themselves.

The school was "definitely putting a lid on the truth," and she was sure there would be a third fainting episode. "You know why? Because there's no punishment for the person responsible."

Indeed, Tapachula was awash in rumors.

Diala's mother tried to enroll her daughter in another school but Diala was rejected. Since she had been among those who fainted, administrators there said they were worried Diala was an addict and would bring drugs to class.

Gladys joined dozens of parents at a press conference in front of Federal 1, where they asked for greater transparency from the school and the local district attorney. A banner went up saying "We demand an immediate response!" in large, red lettering.

On October 18, Esmeralda and six other students from the original episode were called to the Chiapas district attorney's office to be questioned by a psychologist.

"These depositions are going to give us lines of investigation," the lead investigator, José Eduardo Morales Montes, told us. A specialist in cases involving children, his office was investigating the episodes in Tapachula and Bochil. "If one child says they gave candy to someone else, we're going to follow that thread until we know what role which foods played."

Over four hours, the kids were interviewed one by one. Each child was made to stick their thumbs in blue ink for prints, and they mischievously pressed the leftover ink on their fingers into the arms of their friends and parents, making little, smudgy tattoos. As each emerged from their interview, the others teasingly demanded to know if they'd cried.

On the drive back to the neighborhood, everyone sat silently, except Esmeralda and Diala, who whispered to one another as they shared a bag of Doritos.

But little seemed to come of those interviews. As various investigations reached their close, locals were left with muddled summaries and dead ends, rather than answers.

An internal report from the Chiapas DA's office would later tentatively list the cause of the second episode as "probable intoxication through food." But, on the very next page, the report listed "probable transmission through the air" as the culprit.

In another report, the Bochil episode was blamed on "probable intoxication with stimulants." The theory in that case was that water at the school had been spiked with cocaine, which explained why four of the students had tested positive for the drug, but didn't seem to account for the fact that 64 other students, who had tested negative for the drug, had also fainted.

The families in Tapachula, Bochil, and the other affected towns further north near Mexico City — Tlaxcala and Hidalgo — expressed frustration that their children could still be in danger. But there was little they could do.

I returned home to Mexico City along with the last of the national media, resigned that we might never know what was behind the brief but alarming epidemic of fainting spells.

'I've been anticipating something like this'

Back in Mexico City, I learned that not everyone had given up.

Dr. Carlos Alberto Pantoja Meléndez, one of Mexico's few field epidemiologists, had taken an interest in the fainting episodes. When I reached him at his office at Universidad Autónoma Nacional de México, the country's premier medical school, he told me that he had gathered what had been collected by investigators in the affected states and conducted his own analysis.

One by one, he had ruled out almost every possible theory.

Drugs — still the favored narrative — could be excluded, Pantoja Meléndez said, since nearly all of the affected students had tested negative for the most common recreational drugs. "If it were drugs, we would already know," he said. (As for the four children in Bochil and one student from Hidalgo who had tested positive for cocaine, Pantoja Meléndez noted that they could have used the drug weeks or months prior to the incident, since cocaine tests are extremely sensitive.)

Streptococcal bacteria from contaminated food, insecticide poisoning tied to nearby farms, or heatstroke, were plausible explanations, but would have required a multitude of coincidences to occur simultaneously.

Because the symptom onset was immediate — many of the students, including Esmeralda, did not feel sick before fainting — Pantoja Meléndez says the epidemic could not have been caused by anything ingested orally, as the internal organs would have no time to process the toxin.

The pattern of spread through the schools did not match an inhaled toxin either. The epidemic left a scattered signature, instead of taking out entire classrooms as is customary in cases of aerial contamination. Furthermore, many of the schools are not close enough to farms and factories to be affected by pesticides, fertilizers or other industrial chemicals.

There was only one possibility remaining in his view - albeit an unlikely one: mass hysteria, otherwise known as mass psychogenic illness.

Intrigued, I set up a Zoom call with one of the world's leading experts on mass hysteria, Dr. Robert Bartholomew, a psychology professor at the University of Auckland, New Zealand.

Bartholomew has a graying mustache and a habit of interrupting himself as he talks. In his Zoom background is a bookshelf featuring a large volume on the Roswell UFO sightings.

For years, he has collected cases of mass psychogenic illness like coins or pokemon cards, and maintains a database of 3,500 examples going back to the Middle Ages. Since the nineties, he has written over 60 academic papers and several books on the subject.

"I've been anticipating something like this for years," he told me.

In fact, mass hysteria was the theory put forward by a medical team in Veracruz, following fainting episodes at the state's Técnica 67 school on October 17, after a microbiological analysis of food and water samples taken from the school had revealed no bacteria, drugs, or toxins.

Mexican President Lopez Obrador had also hinted at the theory during his daily press conference on October 25, calling the fainting episodes a "mass effect". But the idea got little traction as his own government seemed focused on investigating unintentional poisoning.

It was almost Christmas when we spoke, and Bartholomew told me he planned to devote his winter break to researching the Mexican fainting episodes. Soon, Bartholomew was busily requesting documents from the district attorney's office in Tapachula.

Still skeptical, I contacted another mass hysteria expert, Dr. Simon Wessley, a professor at Kings College in London, and told him about the fainting spells. He replied in an email, and agreed that the facts appeared to be consistent with an epidemic of mass psychogenic illness.

"It looks like a new case," he said.

'An extension of our senses'

Mass hysteria is a rare psychological phenomenon where one person exhibits an unexpected behavior like fainting, screaming, or twitching, and then others in the person's proximity replicate the symptoms involuntarily.

Outbreaks can last a matter of hours, or months, and they occur especially in environments with a strict hierarchy and where people spend a lot of time together, like places of work, religious centers, and schools. While it is often contagious among people who are emotionally close, like Diala seeing Esmeralda faint and then fainting herself, it can also spread between people in the same space who don't know each other.

In the Middle Ages, mass hysteria was known as "dancing mania"; an uncontrollable need to dance. During the renaissance and later the Puritan era, mass hysteria was given religious significance, and sufferers were labeled as witches or were thought to be possessed by demons.

In modern times, cases have often been triggered by a strange odor, like the burning smell in Tapachula. The odor is perceived as a threat, which sparks a fight or flight response.

Adolescents, specifically adolescent girls, are more susceptible to mass psychosis, but it is unknown exactly why. In all but one of the fainting episodes in Southern Mexico this fall, more girls were affected than boys. The only previous documented case of mass psychogenic illness in Mexico was at a girls' boarding school in 2007.

"Adolescents tend to be more naive to the way the world works, right? They're more likely to believe in things like conspiracy theories, bigfoot, space aliens," Bartholomew said. "I know I did when I was that age."

School groups have been the quintessential setting for cases of mass psychogenic illness in this century and the last. In 1962 in Kanshasa, Tanzania, over 1,000 schoolchildren were affected by fits of uncontrollable laughter for months. In 1965 in Blackburn, England, 141 adolescent schoolgirls fainted in one day. Several had fainted from fatigue at a church service and were made to sit in a hallway to recover, where they were seen by their classmates walking through, which is likely how the epidemic spread.

In the early aughts, refugee children in Sweden began experiencing a new psychological condition in which they retreated into a state of reduced consciousness dubbed "resignation syndrome." Between 2016 and 2018, fifty children at a school in Pyuthan, Nepal would cry and shout en masse in periodic episodes.

A diagnosis of mass psychogenic illness can be contentious. It is perhaps uncomfortable for doctors and local officials to blame a psychological effect, especially when people are presenting with physical symptoms that could suggest there's a concrete danger to a community.

In 2011, several students at a high school in Leroy, New York developed uncontrollable twitching and began to garble their words. When the diagnosis of mass psychogenic illness was presented by the New York State Health Department, parents appeared on national television to campaign to get it discredited.

What made the episodes in Mexico so interesting, Bartholomew said, is that they may represent something relatively new, because they spread without immediate social contact between the people affected.

How could hysteria spread across hundreds of miles, through multiple different states, between people who never physically interacted?

'Maybe we'll finally get some answers'

From the outset, the working assumption had been that there was no connection between the middle schools where fainting episodes had been reported.

But in late March, Pantoja-Melendez heard from an epidemiologist in Veracruz who gave him information that challenged that assumption. During her visit to the Técnica 67 school, several students mentioned that they were part of a WhatsApp group that also included students from Federal 1 in Tapachula. News of the initial fainting episodes had been shared there, the epidemiologist, who asked to remain anonymous, told Pantoja-Melendez.

It was the first concrete social media connection between two pools of affected people.

I had mentioned Pantoja Meléndez and Bartholomew to one another and soon discovered that they were working together. Both believe that the fainting episodes in Mexico were examples of something new and alarming: mass hysteria spreading online.

The first signal that this could happen had come during the COVID lockdowns in the UK, when an epidemic of tics was identified in teen girls in the UK, and then in several other countries. The tics appeared to have started after they watched TikTok videos about people with Tourette's syndrome.

In Mexico, according to Bartholomew, as word spread over special media, messaging platforms, and in the news about a "poisoning" or a cartel attack in Tapachula, so too did fear of it spreading to more schools. This, Bartholomew said, led to other kids replicating the very symptoms they'd heard about, often after they sensed something out of place, like a weird smell.

"It used to be that you had to be there. You had to be in the room," Bartholomew said. "But now social media is an extension of our senses, and we're always playing catch up… I think we are on the verge of a much bigger, global epidemic."

Eight months after that first episode in Tapachula, Pantoja Meléndez and Bartholomew are now the only people left investigating the fainting epidemic. Their focus now is mapping out how each episode is linked to the ones that followed.

This summer, teams from Pantoja Meléndez's university are set to visit the six affected schools to interview students and their parents about their social media use and what they had heard about other schools in the days preceding each fainting episode.

Their working theory is that the Internet, coupled with the psychological and developmental disturbance of the pandemic, was the agent of transmission for a mass hysteria episode.

"These children were in their homes for almost two years. That is significant in relation to the connection between the brain and the immune system," Pantoja-Melendez explained. "We've seen all sorts of weird things happen the past year."

Back in Tapachula, Esmeralda is the only one among the 11 students who fainted in that first episode who's still enrolled at Federal 1. The other ten, including Diala, have transferred out.

I called Gladys to tell her about Pantoja Meléndez and Bartholomew's theory, and to let her know the team of epidemiologists would be coming to Tapachula. She still suspects her daughter was drugged, but she told me she was keeping an open mind.

After such painful uncertainty, Gladys says it's meaningful to her that someone cares enough to see the investigation through. "Maybe we'll finally get some answers," she said.