Mystery Illness Strikes Boston Choir—But Was It All in Their Heads?
“The mind has great influence over the body, and maladies often have their origin there.” —Jean-Baptiste Poquelin
On Tuesday evening, July 22nd 2025, a performance by an elite French youth choir at St. Paul’s Church in Cambridge, Massachusetts took a dramatic turn when eight members fell ill. The first person affected had trouble breathing, and was soon followed by several compatriots. The choir members, ages 11 to 13, quickly recovered after being rushed to a nearby hospital. A Hazmat team arrived soon after and swept the building, testing the air quality. The readings were normal. Some audience members said they noticed an unusual odor at the time of the incident.1 Curiously, not a single audience member was affected.
Similar such outbreaks are not uncommon, and as the days and weeks pass without any definitive environmental findings, these episodes often receive the label of “mystery illnesses,” but are almost certainly psychogenic in nature. Psychological factors such as stress, anxiety, and suggestion can trigger physical symptoms, especially children under pressure. In Cambridge, the emotional bonds of a choir, combined with the stress of performing abroad and the presence of a mysterious smell, may have created fertile ground for social contagion.
In the absence of toxins or pathogens, investigators look to behavior patterns for clues. The clustering of symptoms in close-knit groups and the absence of a single audience member being affected is typical of psychogenic episodes. The sudden appearance of transient, benign systems, the spread by line of sight, the presence of an unfamiliar odor, and a rapid recovery, all point to a psychological explanation. Outbreaks of psychogenic illness are common in schools, factories, and religious gatherings–settings where group identity can amplify stress responses. These episodes highlight the delicate interplay between the mind and body, especially in young people navigating unfamiliar environments.
Choral Outbreaks
Such incidents may seem rare and bizarre, but they follow well-established patterns that have been observed for centuries. In many instances, all it takes is for one person to fall ill to trigger a wave of similar symptoms. One infamous incident occurred in Santa Monica, California in April 1989 during the “Stairway of the Stars” concert that featured nearly 600 students from three area high schools. It was a big occasion as it marked the 40th anniversary of the annual event. That evening, as the pupils were warming up their voices and tuning their instruments, a student went down–followed by another and then another. Before long, 247 students ages 12 to 18 were complaining of symptoms ranging from dizziness and headaches to nausea, abdominal pain, and weakness. The concert hall resembled a war zone as ambulances and emergency responders rushed to the scene.2 As with the episode in Cambridge, not a single member of the audience was affected and tests of the air were unremarkable.
Psychological factors such as stress, anxiety, and suggestion can trigger physical symptoms, especially in children under pressure.
Several years earlier, a similar episode took place in East Templeton, Massachusetts. On May 20, 1981, 102 elementary students travelled by bus to their central high school to join 300 other students from nearby schools to rehearse for a major concert that evening that would be attended by nearly a thousand people. Within 30 minutes of rehearsing, several members of the chorus collapsed–some dramatically clutching their throats and gasping for air while others were holding their stomachs and complaining of abdominal pain. Those affected students were removed from the auditorium to recover, but the situation worsened. Within minutes another chorus member collapsed, followed by others. Symptoms included dizziness, fainting, itchy eyes, over-breathing, and weakness.
By the time of the performance, the students had recovered and took part. The concert went smoothly for the first hour and 15 minutes until a stirring rendition of “God Bless America.” During the song, a female student who was situated in the front row crumbled to the floor. Within minutes, four more chorus members collapsed. Still others who felt unsteady were escorted off the stage. In all, 41 students were affected. Fifteen were taken to hospital where they were subjected to a battery of tests ranging from blood work to chest X-Rays, all of which came back normal. Two days later it was announced that the students had been poisoned as 13 urine samples were found to contain n-butylbenzene sulfonamide, a chemical common in plastics and insecticides. Speculation ranged from exposure to Gypsy Moth spray to someone slipping a hallucinogenic drug into the ventilation system. It was later determined that the plastic containers used to collect the samples had been contaminated with the toxic compound. As with the earlier cases in Massachusetts and California, not a single adult in the building reported feeling unwell.3
One of the largest outbreaks of choral hysteria on record occurred in 1959 at Oklahoma State University after 5,400 high school chorus members from across the state had gathered in a fieldhouse for a Song Festival. It was Monday evening, November 23rd and the weather was chilly–a factor that would play a pivotal role. About halfway through the program, many drivers of the nearly 200 busses that were parked just outside the building decided to start their engines and run their heaters so that the students would be warm on the trip home. As a result, some of the diesel fumes were sucked into the air intake fans of the fieldhouse. As the strange smell swept through the venue, several students became dizzy and anxious, and a mass evacuation was swiftly ordered. Most students appeared fine as they left the stadium, only to be stricken as they reached the parking lot as they saw their classmates being treated. In all, over 500 students were affected, with many taken to local hospitals where they quickly recovered.4
Not a Mental Disorder
There is a common misconception that episodes of psychogenic illness are triggered in students with abnormal personality traits or who are experiencing mental health issues. This is a myth.5 They are best described as collective stress reactions that can potentially affect anyone. The symptoms are real and often cause intense physical suffering. While the underlying trigger of outbreaks is anxiety and stress, episodes are based on a belief. We all have beliefs, hence, no one is immune. In choirs, when the first person becomes unwell, it is likely to trigger anxiety in other group members who grow fearful that there may be a mysterious toxin in the air. This often leads to hyperventilation, a racing heartbeat, nausea, and feeling shaky due to an adrenalin rush.
Outbreaks of psychogenic illness are common in schools, factories, and religious gatherings–settings where group identity can amplify stress responses.
Unfortunately, there continues to be a stigma surrounding the diagnosis of mass psychogenic illness as the victims are often labelled as weak-minded or mentally disturbed. Health officials know this all too well and often receive a backlash from angry parents who are adamant that their children were not “hysterical” or the victims of a condition that was “all in their heads.” Of course, this isn’t true–the symptoms are real, but the origin is psychological. As a result, some health officials are hesitant to render a diagnosis of social contagion.
During an outbreak of psychogenic tics at a high school in Leroy, New York in 2011–2012 that made international headlines, for example, the State Health Department initially withheld the diagnosis until their findings were leaked by a neurologist treating some of the children.6 The Massachusetts Health Department took a similar stance in 2012–2013 during a mysterious outbreak of “hiccups” among 18 teenage girls a school in Danvers, formerly Old Salem village. A Freedom of Information Act request would reveal the existence of a report that concluded the students were suffering from “conversion disorder”—AKA mass psychogenic illness—and with the passage of time and the reduction of anxiety, the symptoms should eventually fade away. They did.7
In an age of Covid, global mobility, and social media stoking anxieties daily, we owe it to the public to be transparent about these diagnoses. Public health departments have an obligation to tell the truth no matter how inconvenient that truth may be. When political motives enter the health arena, science can be overshadowed by public relations, leading to fear, uncertainty, and an erosion of public trust.