We Are Convinced That Placebos Work, Even When They Don't

"All you need to do is believe!" —Tinker Bell

A placebo is an inactive substance of faked procedure. Placebos take many forms, such as a sugar pill, saline injection, sham or fake surgery, or verbal suggestion.

The placebo effect is not easy to study. There is a natural tendency for people to feel better and become healthier over time. Therefore, it is always important to compare the placebo with a no-treatment condition, e.g., no sugar pills. Because sometimes conditions improve after placebo treatment, scientists want to understand how placebos work and under what conditions are they most effective.

Open-label placebos

Placebos are sometimes given to appease a nervous patient. Studies have shown that patients feel ill-served if they leave their physician's office without a prescription. Patients are usually not told that are being given a placebo. It has always been assumed that the ruse was an essential component of the placebo effect.

A recent study investigated this assumption by investigating what happens when placebos are administered openly and without deception. If the patient is informed that they will receive a placebo, will they still feel better? This is called an open-label placebo (OLP).

Surprisingly, OLPs are fairly effective for a variety of conditions, including ADHD, depression, chronic lower back pain, irritable bowel syndrome, cancer-related fatigue, and menopausal hot flashes. That sounds impressive, but all these positive effects were based on self-reports by the patients. Studies have concluded that patients suffering from chronic or refractory diseases are more likely to place hope in novel interventions and scientifically unproven treatments, such as chiropractic manipulations or strange herbs, as well as OLPs.

A recent study sought to understand the conditions and mechanisms underlying the actions of OLPs without the confounding influence of patients' expectations. Previous studies have shown that OLPs are more effective the more suggestive the instructions that accompany the placebo’s administration. For example, if the person of authority, such as a physician, administering the placebo treatment is convincing, the OLP becomes more effective from the patient’s perspective.

A meta-analysis of 21 studies involving 1355 patients revealed a small to medium OLP effect for self-reported outcomes and no OLP effect for objective outcomes. The positive effect for self-reported outcomes in healthy individuals is consistent with other investigations. Essentially, people who knowingly take placebos believe that they are getting better even if there were no objective improvements in their health. How is this possible?

Subjectivity and the placebo effect

The placebo effect is greatest for two subjective brain conditions: the experience of pain and mood. Essentially, if you think that a drug will take away your pain, it will—at least somewhat. If you think that a drug will make you happier, it will—at least somewhat. The personal experience of pain is impossible to confirm objectively. Patients are asked to estimate their pain from 1 to 10. The same is true for how happy or depressed someone feels.

Thus, it is not surprising that recent clinical studies have reported that the placebo response is particularly large in major depressive disorder (up to 50 percent). Furthermore, for reasons that no one can yet explain, the placebo response rate has been steadily increasing over the past several decades. Possibly the human brain is evolving better mechanisms to defend itself against pain and depression. I would like to think so.

Unfortunately, our amazing ability to imagine ourselves mentally healthy (and mentally unhealthy, because it works both ways) has made it more difficult to prove that new drugs are effective compared to placebos. This is a central reason behind the decision of several pharmaceutical companies to reduce or even close their psychiatric research and development programs. It simply became too expensive to continue trying to prove that a new drug was better than a placebo.