A placebo is defined as a simulated or otherwise medically ineffectual treatment, often given to patients as a control in medical research. This rather clinical definition doesn't begin to describe the placebo effect, however, a mystery of modern medicine where symptoms improve as a result of taking, well - nothing. With placebos found to work in multiple trials and some placebo treatments known to work better than conventional cures, perhaps there is more to medicine than we currently understand.
While placebo treatments have been studied multiple times, the placebo effect itself remains mysterious. In any clinical trial, a drug is described as a certain percentage better than a placebo at treating specific conditions. However, this percentage is smaller than the difference between taking the drug and getting no treatment at all, hence - the placebo effect. In essence, the placebo effect refers to all the effects of taking a medication that can't be attributed to the treatment itself.
Much more than a simple trick of the mind, however, the placebo effect highlights just how important our expectations are when receiving medication. People who expect a placebo will make them feel better will generally feel better, with the opposite also being true. It seems the very attitude you take into a situation affects the outcome on a measurable and repeatable basis. Just because all placebos have no therapeutic value by definition, however, they are certainly not all the same.
The context surrounding a placebo treatment can dramatically affect the outcome, with some pretty strange results. For example, blue placebo pills are more likely to be experienced as downers, with red pills being uppers. Also, injections will generally be experienced as more powerful than pills, with big pills working better than small ones. Identical placebos are even experienced differently depending on location, with different cultural mind-sets often thought to be responsible.
If you think this sounds like crazy talk, you're certainly not alone. However, time and time again, research has found that a particular mind-set or belief about one's body or health can lead to improvements in disease symptoms. Not only that, but changes to appetite, vision, and even brain chemicals have also been reported, showing just how connected the mind and body really are. The effects of migraines, asthma, depression, and Parkinson's disease have all been treated successfully with placebos, along with a variety of other ailments that involve the subjective experience of symptoms.
There is a long history of pain relief research using placebos, including a World War II study by Dr. Henry K. Beecher where soldiers were successfully treated with salt water instead of morphine due to low supply. According to Ted Kaptchuk in a much more recent study published in Science Translational Medicine, "There was no difference between the pharmacology of the drug in reducing pain and the placebo dressed up with a nice word... Basically we show that words can actually double the effect of a drug. That's pretty impressive."
Perhaps the weirdest thing of all, however, is that placebos work even when patients know exactly what they're taking. According to another study by Ted Kaptchuk et al. in the Public Library of Science journal PLoS ONE, the very act of ministering to patients seems to have a positive effect. While this admittedly makes little sense at first glance, at the very least, it highlights the importance of relationships in medicine and makes us realise just how little we comprehend the complex links between body and mind.