In his new book, "Suggestible You: The Curious Science of Your Brain's Ability to Deceive, Transform and Heal" (National Geographic Publishing, November 2016; 288 pages), science writer and Scientific American contributor Erik Vance seeks to explain one of our brain's most remarkable powers: its ability to heal both mind and body. Vance explores the profound influence our thoughts, feelings and expectations can have on our well-being—how a positive outlook can, for example, help ease physical pain. The ways in which this mind–body link manifests remain mysterious, but decades of research have clued us in to some fascinating connections. Vance talks to Scientific American MIND about his investigation of the placebo effect.
[An edited transcript of the interview follows.]
What made you want to write about the placebo effect?
This topic has been my obsession since I wrote a profile of Tor Wager, a placebo researcher in 2010. I was raised in Christian Science and he was a Christian Scientist, too.* It is kind of like lapsed Catholics studying the brain chemistry of guilt. It fits really well. A lot of my interest also tied back to my childhood because of things I had seen and couldn't explain as a kid. My father had a [religious] healing of a terrible rotator cuff injury that forced him to leave professional baseball. A friend at the church cut his toe and saw it grow back, including the toenail. The importance of these events is their power to set up expectation in the minds of the members of the community. It's just something that resonates for people who have been in healing or faith communities. That's how I got hooked. I was like "Oh my God, scientists might be explaining all this stuff!"
What do we know now about the neuroscience behind the placebo effect?
I participated in a placebo experiment where I was electrically shocked. The researchers essentially blocked my pain just by showing me a green light before delivering it. I got fooled completely. That experience really got my attention. It taught me that this is not about being gullible or stupid: this is about brain chemistry. Opioids, dopamine, endocannabinoids, serotonin… There's probably around 30 [neurotransmitters and hormones] involved in this effect. And scientists are still finding new ones.
Hopefully, I can help the reader get a little closer to understanding the complexities [of the placebo effect]. When different phenomena—our thoughts, hormones, medications—start interacting, the science gets real messy, real fast. Even with something as seemingly straightforward as endogenous opioids, such as endorphins, when you look at the other mitigating factors and how the opioids and dopamine interact and cancel each other out, it suddenly gets complicated. And that's the easiest of these pathways we've found.
The efficacy of all new pharmaceuticals are measured against that of a placebo treatment. Should we fix that?
Of course, in theory, pharmaceutical companies would love to eliminate the placebo response. It would make drugs cheaper and easier to make. But in reality no one is quite sure what would happen without a placebo response. If the response rate is exactly equal between the drug arm and the placebo arm in a drug trial, say 30 percent just as an example, there would be no change in the outcome. Both sides would just be 30 percent weaker. But early evidence suggests that's not the case—there are many interactions between internal chemicals triggered by expectation and also with the drug itself. The only way to know for sure is to probe deeper into the chemical nature of belief.
Although there may be little doubt about the power of placebo, just how predictable an effect is it? Could a sugar pill ever work reliably as a remedy?
Yes, naturally. That's why as many as 70 percent of doctors admit to occasionally prescribing remedies that, while not strictly placebo, are more psychological than physiological. But I think this question misses the point. The lesson to take from this research is not whether or not doctors should prescribe placebos—they already do—or whether patients should take them—we already do—the lesson is about adding them to proven treatments and using them responsibly. Adding them to proven therapies means that doctors understand the incredible power of the placebo response to aid their treatment of pain, depression and other maladies. Using them responsibly means that patients understand their sizable limitations in curing life-threatening diseases.
Could patients harness the power of the placebo effect to use on themselves if they wanted?
I find that the power is in the narrative. It's in the story telling. It's in the sensory experience. You have to think about yourself. Some people are into ancient mysticism, and that really resonates. I don't think there's anything wrong with admitting to yourself that something might be a placebo, but just going with it anyway.
There's no lack of placebos to try, following my rules. Don't go out there looking for minke whale eyeballs or cures from other endangered species. Treating tumors isn't the place to play with this effect because they don't respond to the endogenous chemicals of placebo. But chronic pain might be. I talked to one of the leading doctors in the country. He said he's lucky if he can help 40 percent of his patients [with prescription pain relievers]. He often tells people to go back to church, if they are lapsed. Not to get back into god, but to get a sense that things are going to be okay and get some calm.
Does knowing more about how placebo effect works reduce its impact? Has it reduced yours?
Personally, I'm not a great placebo responder, especially not now. I think it's okay to read this book and maintain a healthy placebo response. But I don't know if it's possible to write a book about it and maintain a healthy response. I might be a little broken at this point. I'm sure it will come back.
*Editor's Note: Many Christian Scientists avoid most medical treatment, turning instead to prayer for healing.