How does the placebo effect affect our brain?

Introduction

Are you familiar with the term 'Placebo Effect'? While there are various scientific explanations for it, a simple and direct definition is the tendency of any medication or treatment to produce results simply because the recipients believe it will work. Looking back, the placebo effect was first discovered and demonstrated by English physician John Haygarth in 1799. He conducted an experiment involving a medical treatment known as 'Perkins tractors,' which were highly popular during his time.

The ‘Perkins tractors’ were invented by physician Elisha Perkins and consisted of two small metal rods, one made of brass and the other of iron, with a pointed end. These rods were rubbed over an inflamed or painful area to alleviate a patient’s distress.

Although many scientists and doctors considered Perkin’s treatment devices quackery, the popularity of ‘Perkin tractors’ soared from the late 18th to the early 19th centuries. Consequently, numerous physicians conducted experiments on their patients using Perkins tractors made of various materials. Astonishingly, they discovered that as long as the patients believed they were receiving genuine treatment with Perkins tractors, the materials used didn’t matter; all materials were equally effective. These early studies laid the foundation for what is now known as the placebo effect.

Although the placebo effect was discovered hundreds of years ago, it remained a mystery for a long time. Consequently, numerous research studies and experiments were conducted to uncover the science and psychology behind this phenomenon. One of the latest research studies, conducted at Harvard University in 2021, focused on testing people's reactions to migraine pain medication. The study divided participants into three groups: the first group received a migraine drug labelled with the drug's name, the second group received a placebo labelled 'placebo,' and the last group received nothing. Surprisingly, the experiment's conclusion revealed that the placebo was as much as 50% effective as the drug in reducing pain after a migraine attack.

Studies of the Placebo effect

In another study, individuals received a placebo, which they were informed was a stimulant. Subsequently, upon taking the pill, their heart rate accelerated, blood pressure rose, and their reaction times improved. Conversely, when these same individuals were administered the identical pill but were informed it was intended to help them sleep, they experienced contrasting effects. From this result, experts suggested a correlation between the intensity of a person’s expectations and the likelihood of achieving desired outcomes. The stronger the anticipation, the greater the probability of experiencing positive effects. The dynamic interaction between patients and their healthcare providers might play a profound role in these outcomes.

After reviewing these past experiments, a fundamental question emerges: how does the placebo effect work? Neuroscientifically speaking, placebo treatments trigger the release of neurotransmitters, stimulate hormone production, and activate immune responses in the brain. This can relieve symptoms of pain, inflammatory diseases, and mood disorders. Scientists have discovered that the placebo effect increases activity in the ‘rostral ventromedial medulla ( RVM)’, a region involved in transmitting sensory information between the brain and spinal cord while decreasing activity in the ‘periaqueductal grey’, a midbrain region that modulates pain, fear and anxiety. As a result, the placebo effect has a psychological impact, reducing tension and the production of stress chemicals in the body. The placebo effect can make individuals feel better by prompting the release of endorphins.

Conclusion

However, it’s important to note that the placebo effect can also have a negative counterpart known as the ‘nocebo effect’. If you’re interested in learning more about the nocebo effect's potential dangers, you can explore another article titled ‘To what extent can the nocebo effect be harmful to humans?’ on our website.