In late 2022, as the fentanyl drug overdose epidemic intensified across the United States, law enforcement officers involved in street busts of the synthetic opioid began reporting what they believed were life-threatening reactions.
In Florida, an officer lost consciousness after touching a powder she suspected was fentanyl, describing feelings of lightheadedness and difficulty breathing. Her department attributed her reaction to fentanyl exposure. Similarly, in Ohio, an arresting officer became disoriented and unsteady after noticing a small amount of white powder on his sweatshirt, later recounting feelings of panic and a loss of balance. In 2024, two NYPD officers fell ill during a fentanyl bust in a Bronx apartment, requiring medical attention. In both of these instances, fentanyl exposure was the presumed cause.
However, according to Dr. Helen Pilcher, author of "This Book May Cause Side Effects: Why Our Minds Are Making Us Sick," these incidents may be examples of the nocebo effect, which she describes as the opposite of the placebo effect. The nocebo effect occurs when negative expectations lead to negative health outcomes. Pilcher suggests that the officers did not actually overdose but experienced "functional seizures" and collapsed because they expected to.
"When people are warned to expect symptoms, they become more likely to experience them," Pilcher writes. "Positive expectations lead to positive health outcomes. Symptoms improve, illness fades," while "dark expectations can sometimes spawn truly dark realities."
Pilcher cites the case of a patient in Nashville, Tennessee, who died of esophageal cancer after being informed that the cancer had spread and could not be treated. An autopsy revealed no evidence of widespread cancer; the patient had been given another patient's diagnosis due to a mix-up. Pilcher noted that "the doctor’s words were as effective as poison."
During the COVID-19 pandemic in Germany, some individuals developed symptoms such as chronic jaw pain, fatigue, and shortness of breath after watching a YouTuber discuss his own symptoms. Pilcher believes these symptoms were generated by subconscious processes in the brain. The World Health Organization has also observed that extensive media coverage of COVID-19 symptoms contributed to some people feeling ill, even without contracting the virus.
The nocebo effect is not a new phenomenon. Pilcher traces its origins back at least 200,000 years, citing historical accounts of "hex deaths"—individuals dying after believing they were cursed. In 1857, a Portuguese naturalist documented men dying after being cursed by a medicine man, a phenomenon corroborated by a Brazilian historian centuries later.
In 1942, Harvard Medical School physiologist Walter Cannon coined the term "voodoo death," describing how psychological threats could trigger physical responses. He noted that an adrenaline rush, initially a survival mechanism, could become toxic. Cannon posited that living through extreme stress, such as a pandemic, earthquake, or a perceived curse, increases the risk of fatal heart attack, stating that "an ominous and persistent state of fear can end the life of a person."
In recent years, social media has amplified the nocebo effect, accelerating the spread of nocebo-generated symptoms. Pilcher advises caution regarding online health information, recommending that individuals with symptoms consult a qualified medical professional rather than relying on internet searches or social media platforms.