The placebo effect is important to our understanding of how to differentiate treatments that work versus those that don’t. However, I think most see placebo effect as just the body healing itself by the power of suggestion (if you take a sugar pill but think it’s a treatment your expectation causes healing). If this is all the placebo effect is, it would suggest a kind of magic: that people’s bodies can mystically heal themselves by Mind Power.
In reality, the placebo effect is any improvement not linked to the treatment. This includes:
- The body healing itself from suggestion. It’s an important mechanism but not the whole of the placebo effect. It obviously depends on the disease. It’s much more likely to work for a headache (especially since pain is a product of the mind) than cancer.
- The disease naturally running its course: I participate in a study on a drug to cure the flu. I’m given a placebo and the flu goes away of its own accord. The thing to note is my cure had nothing to do “mind-over-matter”. This example of the placebo effect is rarely explained in media stories.
- The patient believing they are healed. Have you ever been prescribed a drug and then you’re constantly thinking you’re getting better because you’re hyper-sensitive to any improvement you have? This can happen even if the drug isn’t working. To take the same example, I’m given the placebo and I think it’s the flu drug. If I’m expecting to be cured I might think I’m feeling better even though the flu is not actually improving. I remember all the little fluctuations of improvement and forget all the little downturns. Once again this is not mind-over-matter but rather mind-misinterpreting-the-body. This one is especially important where the patient needs to self-report on their condition.
So, whilst the body does have a healing mechanism that is related to the mind (eg. resting/relaxing will usually help you heal faster), there’s no reason to see the placebo effect as anything supernatural. Finally, it’s very interesting that the placebo effect applies to animals. So either the animals know they’re being given a drug or, more likely, the 2nd mechanism from the list above (the disease running its course) drives it.