How does a placebo work?

[dimreepr]

I think it's safe to assume, on this site, that we all agree that the placebo effect is real, and that it depends on deception. By which I mean our subjective expectation of the effectiveness of the medication (sugar pill) we're given.

But a recent (small) study, in which the patients were told that they'd be given a sugar pill, the results were almost the same as deceptive trial; one of the patients suffering from severe IBS, was medically trained and knew a sugar pill would have no medical benefit, but she took them anyway; not only was her IBS symptoms gone, but when she ran out of pills, the symptoms returned almost over night.

 Anyone care to take a stab at a possible explanation?

[iNow]

I believe the gut microbiome is implicated, and likely further activated by brain activity / focus type. What we believe and think has an enormous impact on what we feel and what our bodies do. 

For comparison, think about how the likelihood of elderly death spikes tremendously when a lifelong spouse of decades passes away and the surviving spouse remains. That surviving spouse tends to die within a year or three, almost without fail.

That same feeling of loneliness and depression which leads to death can similarly lead to health outcomes when the feeling is replaced by "hope" or "belief that medication is helping."

The mechanism seems to be neurotransmitter flows and volumes, and the impact of the gut, but I'll defer to our biological experts here in case I've misstated or over exaggerated anything in error. 

[TheVat]

That study also underscores the way the placebo effect gets at subconscious processes in the brain, so that even someone told it's a sugar pill and we presume will no longer consciously believe in the treatment effectiveness, still shows a benefit.  That is how powerful suggestion can be, bypassing our rational mind.

[Danijel Gorupec]

3 hours ago, dimreepr said:

not only was her IBS symptoms gone, but when she ran out of pills, the symptoms returned almost over night.

Self-reported or measured symptoms?

[dimreepr]

On 4/12/2023 at 3:05 PM, TheVat said:

That study also underscores the way the placebo effect gets at subconscious processes in the brain, so that even someone told it's a sugar pill and we presume will no longer consciously believe in the treatment effectiveness, still shows a benefit.  That is how powerful suggestion can be, bypassing our rational mind.

Indeed +1, but that also shifts the study to the metaphysical, it's there but I can't touch it or prove it or use it, with a box of tic-tac's...

“I've lived through some terrible things in my life, some of which actually happened.”

― Mark Twain

[Moontanman]

What is the percentage of people the placebo effect actually works on? Seems a bit like faith healing to me, "as long as you believe" I've had the placebo effect tried on me once, I was hospitalized after a terrible boating accident. I was injured severely with broken bones and internal injuries, as lay in the hospital in extreme pain the doc wasn't comfortable giving me more pain meds so he conspired with my wife to pretend to give me a "new groundbreaking pain medicine" They gave me an injection with a large amount of theatrics and it had no effect at... I continued to be in extreme pain. I've never forget those six weeks in that hospital, makes my heart rate climb just thinking of it. BTW contrary to what movies and TV tell you people don't just lose consciousness when they are in extreme pain.   

[CharonY]

The placebo effect is quite interesting, but suffers to some degree from bad data. It generally does not work well for extreme or acute conditions, but the effect is more pronounced (as expected) when it comes to chronic and more subjective measures (i.e. chronic rather than acute pain, for example). 

In some cases, it is not the placebo itself that has a positive affect, but the mere enrolment into a controlled trial (e.g. heightened interactions with medical professionals). Some neuroimaging strategies indicate that there are certain changes in the brain and it has been speculated that there is a connection to the immune and inflammation pathways. Animal studies have shown that deception might not be necessary for certain types of outcome (though in some cases it is the experimentator/pet owners that are deceived).

 

 

[TheVat]

1 hour ago, CharonY said:

In some cases, it is not the placebo itself that has a positive affect, but the mere enrolment into a controlled trial (e.g. heightened interactions with medical professionals).

Yup.  Immune response, analgesia, inflammation, BP, resting heart rate, all respond to increased interaction with people recognized as sympathetic.  You could be Paul Kurtz, James Randi, Richard Dawkins, and if a shaman walked into your hospital room and began shaking a gourd full of seeds over your body and chanting, some of your biomarkers would improve.  

For sure, they would improve more if you had a deep cultural belief in the shaman's methods and healing powers.  

[CharonY]

11 minutes ago, TheVat said:

For sure, they would improve more if you had a deep cultural belief in the shaman's methods and healing powers.  

That is something I am actually uncertain about. I.e. whether the response can be modulated in strength. The response tends to be on mild side with various release of e.g. dopamins, cannabinoids, opioids and so on. For some of them, we know that there is a release even from simple pleasurable interactions (e.g. talking to a friend).

While the perceived effect might change in strength, I am not sure whether the measurable biomarkers respond in kind. Of similar interest are nocebo effects