ANTICIPATING THE NEGATIVE—THE NOCEBO EFFECT
Today I received an email from the Mayo Clinic promoting a new book: The Nocebo Effect -When Words Make You Sick. I don’t plan on ordering the book, but I did want to find out what a nocebo effect is, never hearing of it before. Here are highlights from the Mayo Clinic blurb, Can Words Make You Sick?:
An investigation of the nocebo effect—the placebo effect’s evil twin
“The nocebo effect” is a phenomenon best summarized as the occurrence of a harmful event that stems from consciously or subconsciously anticipating it. The most recent and massive demonstration of the nocebo effect was found with the claims of COVID vaccine side effects, where a significant portion of these side effects were not actually caused by the vaccine. Instead, they were the result of our negative expectations, the so-called nocebo effect.
There are myriad other examples throughout history, and recent studies have documented the critical role of the nocebo effect in treatment side effects—such as with statins for high cholesterol, the higher incidence of complaints after negative media reports of certain medicines, and the mysterious illnesses associated with the Havana Syndrome, during which dozens of US government employees fell ill after reportedly being exposed to an unidentified sound wave.
This sparked my interest! I went looking for more in-depth research on this subject, especially as it concerned COVID vaccines. I found it in a two-year-old online article in The Guardian, ‘Nocebo effect’: two-thirds of Covid jab reactions not caused by vaccine, study suggests.
US researchers show negative version of placebo effect behind many symptoms such as headaches and fatigue
More than two-thirds of the common side-effects people experience after a Covid jab can be attributed to a negative version of the placebo effect rather than the vaccine itself, researchers claim.
Scientists in the US examined data from 12 clinical trials of Covid vaccines and found that the “nocebo effect” accounted for about 76% of all common adverse reactions after the first dose and nearly 52% after the second dose.
The findings suggest that a substantial proportion of milder side effects, such as headaches, short-term fatigue, and arm pain are not produced by the constituents of the vaccine, but by other factors thought to generate the nocebo response, including anxiety, expectation and misattributing various ailments to having had the jab.
In view of their results, the researchers argue that better public information about nocebo responses may improve Covid vaccine uptake by reducing the concerns that make some people hesitant.
“Telling patients that the intervention they are taking has side-effects that are similar to placebo treatments for the condition in randomized controlled trials actually reduces anxiety and makes patients take a moment to consider the side-effect,” said Ted Kaptchuk, professor of global health and social medicine at Harvard medical school, and a senior author on the study. “But we need more research.”
Kaptchuck and Dr Julia Haas at the Beth Israel Deaconess Medical Center in Boston analyzed adverse events reported during a dozen clinical trials of Covid vaccines. In each trial, those in the placebo arm were given injections of inactive salt solution instead of vaccine. The study did not look at severe, rare side effects such as blood clots or heart inflammation.
Writing in the journal Jama Network Open, the researchers describe how after the first injection more than 35% of those in the placebo groups experienced so-called “systemic” side effects, such as headache and fatigue, with 16% reporting site-specific ailments including arm pain or redness or swelling at the injection site.
As expected, those who received a first shot of vaccine were more likely to experience side effects. About 46% reported systemic symptoms and two-thirds experienced arm pain or other localized symptoms at the injection site.
When the researchers looked at side effects after the second jab, they found the rate of headaches or other systemic symptoms was nearly twice as high in the vaccine group compared with the placebo group, at 61% and 32% respectively. The difference was even greater for local ailments, reaching 73% among those who had the vaccine and 12% in the placebo group.
Overall, the researchers calculate that about two-thirds of common side-effects reported in Covid vaccine trials are driven by the nocebo effect, in particular headaches and fatigue, which many Covid vaccine leaflets list as the most common adverse reactions after a shot. [underlining mine]
While evidence suggests that information about side-effects can cause people to misattribute common ailments to the vaccine, or make people hyper-alert to how they are feeling, Kaptchuk argues for more information about side-effects, not less. “Most researchers argue that patients should be told less about side-effects to reduce their anxiety,” he said. “I think this is wrong. Honesty is the way to go.”