Decode special effects of placebo

Some people may be genetically programmed to feel better after taking placebo pills, while others may only heal with real pills, according to a new study.

Discover the mystery of the special effects of placebo

Kathryn Hall of Harvard Medical School and colleagues conducted a new study of existing studies on placebo. Their goal is to look at the evidence that some people's genes can make them more likely to experience placebo effects.

If this is confirmed and the genetic characteristics of such "placebo " responders can be identified, it could change the way we prescribe medications and design tests. drug.

In Trends in Molecular Biology magazine, Ms Hall's team noted that previous studies have suggested that human reactions to placebo therapies could be influenced by the way molecules emit certain signals. in the brain and body how to respond to pain and reward or expectation of those experiences.

Among the important signaling systems identified there are systems that involve drugs that respond to specific pain or mood, such as serotonin and dopamine systems , such as pain or mood. The difference between people about how these systems work may be related to their genetic variations.

Evidence of a placebo effect was first published in 1978, after an experiment in patients with molar extraction. Test results showed that some people experienced a feeling of pain relief when taking a placebo, instead of narcotic painkillers.

Recently, researchers also examined the COMT gene , which plays a role in regulating the amount of dopamine in the brain and is associated with pain and pleasure sensations . In one trial, the team provided three types of placebo treatment for patients with gastrointestinal upset syndrome. Specifically, patients are either placed on a waiting list for treatment, given a fake acupuncturist by an unfriendly person or by an affectionate person who performs a fake acupuncture.

After that, the experts checked which patients owned the COMT version. People with this gene variant with a high dopamine content were found to be the most likely subjects to notice, fake therapy actually has analgesic effects.

Although the results of the study are remarkable, the authors acknowledge "the discovery of several interrelations between gene variants and placebo reactions before certain drugs do not specify a mobile basis." A question that remains unanswered is whether the genetic characteristics that promote a placebo reaction before this drug are similar to promoting a placebo response to another drug. may be completely different ".

Ms. Hall and colleagues also mentioned moral challenges in using genetic descriptions to prescribe medication . Doctors may require genetic testing before prescribing certain medications, but what will happen if the patient refuses the screening.

Experts also raised the possibility of changing the gold standard for clinical trials for new drugs. Currently, clinical trials are being conducted with a group receiving placebo and another group of experimental drugs. However, Ms. Hall believes that one more group should not be treated. She said this could help measure the level of any placebo reaction and help determine the effect of the drug better.