Sunday, February 9, 2020

The Placebo Effect

One of the main reasons for failure of new drugs in clinical trials is the placebo effect. Placebos given to patients in controlled clinical trials elicit measurably beneficial effects that are good enough to make the drug look statistically no better than the placebo. The drug then fails and tens or hundreds of millions of dollars in investment returns nothing but the valuable information associated with the failure, which isn’t a marketable product. Strong placebo effects even pop up in diseases like Parkinson’s Disease where normal disease progression would be expected without some form of therapeutic drug.



Placebo effects are biological, not magical
The study of placebo effects are still early, but progress is being made. In Parkinson’s, placebo effects are believed to arise partly from release of dopamine in the brain: “We show here that the placebo effect in Parkinson’s disease is due, at least in part, to the release of dopamine in the striatum. We propose that the placebo effect might be related to reward mechanisms. The expectation of reward (i.e. clinical benefit) seems to be particularly relevant. According to this theory, brain dopamine release could be a common biochemical substrate for the placebo effect encountered in other medical conditions, such as pain and depression. Other neurotransmitters or neuropeptides, however, are also likely to be involved in mediating the placebo effect (e.g. opioids in pain disorders, serotonin in depression).”

Placebo effects are being correlated with genetic traits. For example, in irritable bowel disease, a small gene variant in the catechol-O-methyltransferase gene (val158met) is correlated with an increased placebo response. That gene is relevant to metabolism of the neurotransmitter dopamine. Research on placebo effects also includes health care provider social behavior (bedside manner). Placebo effects can be powerful in mental disease treatments: “The placebo effect—the ability of expectations about a treatment to lead to clinical improvement—is well established as a powerful force in mental health interventions. The placebo effect is responsible for a substantial portion of the efficacy of antidepressant medications and other important elements of psychiatric care.”

Placebo effects are also prominent in pain therapies: “The placebo effect is a powerful mechanism for modulating clinical outcomes. Linked to psychoneurobiological changes, placebo effects result from the expectancies of the patient, proxy, and provider (1, 2) and are distinct from regression to the mean, spontaneous remission, and fluctuations in symptoms. In randomized clinical trials, the inclusion of a no-intervention arm (3) and possibly a measurement of expectations (4) are critical design elements that can help separate placebo effects from these potential confounds (5). This phenomenon has been particularly well investigated in the areas of experimental and clinical pain, but placebo effects can influence any treatment and any condition (6).” (emphasis added)



Chi, acupuncture, nutritional supplements & Goop
People report feeling better from a vast number of ailments and diseases. Products are sold that infer or outright claim to be good to treat all sorts of diseases and symptoms. Most of it is based on pseudoscience and/or outright fraud. For example, acupuncture claims to be based on inserting thin needles in precise locations on the body to affect the flow of Chi or life force in clinically beneficial ways. Despite the claim, (1) there are no precise locations that experts use to affect the flow of Chi, and (2) Chi doesn't exist. Efforts to proves it exists have failed. Paltrow’s products marketed under the Goop brand name may elicit placebo effects in at least some people based on pseudoscience at best.[1] Nutritional or dietary supplements usually have no useful ingredients other than minerals and vitamins that are considered to be actual necessary nutrients.



I don’t care about science, I want to buy it anyway
Some people don’t care that the product they buy doesn't work beyond being a placebo. Others reject science arguments because they believe their product really “works.” Often they just want to be left alone about it and free to buy whatever they want.

There’s a lot to buy.[2] The global market for dietary supplements alone is projected by one study to be about $350 billion by 2026. Paltrow’s Goop products can be expensive. A 2002 study estimated that US consumers paid about $34 billion for complementary and alternative medicine (CAM) therapies, acupuncture, reflexology, aromatherapy, herbal therapy, etc., but the clinical benefits were not quantified due to a lack of good data for analysis: “Nevertheless, there are still too few good quality evaluations to draw many conclusions about the cost-effectiveness of specific CAM therapies for particular conditions.”

In view of existing evidence, it is reasonable to believe that essentially all benefit that people report for products and therapies that are not FDA approved come from the placebo effect. It is also reasonable to believe that people will continue buying various non-FDA approved products in the belief of benefits that arise from something other than the placebo effect.


Footnotes:
1. Scientific belief that benefits from Chi, acupuncture, nutritional supplements and Goop are based on placebo effects have been rejected by some people. That belief is criticized as closed-minded worship of a fallible and flawed Western science that does not fully understand all of the things it pretends to know. Some of that criticism is true because Western medical science doesn't understand everything, but at least it doesn’t claim to. However, that limitation does not negate the placebo effect or show evidence that convincingly demonstrates effectiveness of alternative treatments beyond placebo effects.

The ‘not enough evidence’ criticism has been rejected as raising the bar higher for alternative approaches compared to FDA approved drugs. The rebuttal to that is that higher levels of evidence can be reasonably asked for inherently inexplicable theories, such as Chi, and treatments or products that operate without any basis in science other than placebo effects. After all, no one has measured Chi, despite years of trying. Such a finding would be a major new scientific finding that would ripple through biomedical research if not most all other sciences as well. So far, no such finding has been published. Almost all placebo controlled clinical trials with nutritional supplements have failed, which is why none are FDA-approved.

2. All non-FDA approved nutritional or dietary supplements and homeopathy products are required to include this disclaimer related to any medical or clinical benefits the product is claimed to have:

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

In other words, such products do not have to do anything medically useful and they cannot make any such claim. They may elicit a placebo response in some consumers.

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