A new commentary by Ted Kaptchuk in the New England Journal of Medicine explains what is known about placebos — including the side effects people can experience after getting fake treatments — and why doctors might want to use them:
Medicine's goal is to heal, which can include cure, control of disease, and symptom relief or provision of comfort. When no cure is available — an inevitable occurrence at some points — medicine's ultimate mission is to relieve unnecessary suffering. Supportive and attentive health care (preferably with effective medications, but even without) legitimately creates a "therapeutic bias" in patients toward hope and an experience of relief and reprieve.
In particular, there are three things science has revealed about the placebo effect, which can be instructive for doctors. According to Kaptchuk, a professor of medicine at Harvard Medical School and director of the Harvard-wide Program in Placebo Studies & Therapeutic Encounter (PiPS), they are:
- Placebos can help with symptoms, though they rarely cure people. For example, giving patients with cancer placebos has minimized the side effects of cancer treatments — such as nausea and hot flashes — but placebos have not been shown to shrink tumors. So placebos haven't been shown to alter the course of diseases, but can have an impact on their related symptoms.
- The context of a placebo or treatment, including their labels and how they're given out, can change how effective they are. Kaptchuk points to a recent study on migraines, which found that when patients took a medication labeled "placebo," the pain-relieving effects were the same as for patients given placebos labeled with the drug name. However, when patients were given the drug with its actual label, the painkilling effects increased by 50 percent. In other words, it wasn't just about giving patients sugar pills; how they were labeled mattered too.
- Placebos can have adverse side effects. These are known as nocebo effects. "Research reviews have estimated that 4 to 26% of patients who are randomly assigned to placebos in trials discontinue their use because of perceived adverse effects," he writes. "It thus seems not unlikely that patients are often treated for adverse medication effects that are actually anticipatory nocebo effects." This insight can inform both how doctors consider using placebos and how they might interpret patients' negative reactions to actual medicines.
Near the end of the piece, Kaptchuk makes a final argument for using placebos — and how doctors' interactions with patients can confer healing benefits in and of themselves:
Research on placebo effects can help explain mechanistically how clinicians can be therapeutic agents in the ways they relate to their patients in connection with, and separate from, providing effective treatment interventions. Of course, placebo effects are modest as compared with the impressive results achieved by lifesaving surgery and powerful, well-targeted medications. Yet we believe such effects are at the core of what makes medicine a healing profession.
If you're fascinated by the placebo effect, check out these other interesting studies:
- This study demonstrated that hotel cleaners who were told their work is good exercise lost weight after four weeks compared with a group that wasn't given that message.
- Researchers studied the placebo arm of 20 years' worth of trials on antidepressants and found that over time, people who were given placebos perceived them to be more powerful, suggesting that our changing cultural notions about the medicines may impact placebos' effects.
- This study showed that drug labeling impacted how people perceived the placebos' effectiveness for migraines.
- Researchers have found that the color and size of a pill impacts how well people perceive them to work. In this study, people thought red and yellow pills were stimulants, while blue pills were classified as depressants.