Image by John Hain from Pixabay

October 9, 2023

The Power of Suggestion

Can our thoughts affect us at a biological level not just a subjective level?

In a new study published in pre print in BioRxIV entitled: A thalamic circuit represents dose-like responses induced by nicotine-related beliefs in human smokers, we see some new research looking at the power of suggestion well beyond the placebo effect.

The abstract reads as follows: "Could non-pharmacological constructs, such as beliefs, impact brain activities in a dose-dependent manner as drugs do? While beliefs shape many aspects of our behavior and wellbeing, the precise mapping between subjective beliefs and neural substrates remains elusive. Here, nicotine-addicted humans were instructed to think that an electronic cigarette (e-cigarette) contained either “low”, “medium”, or “high” levels of nicotine, while nicotine content was kept constant. After vaping the e-cigarette, participants performed a decision-making task known to engage neural circuits affected by nicotine while being scanned by fMRI. Activity in the thalamus, a key binding site for nicotine, increased parametrically according to belief dosage. Furthermore, the functional coupling between thalamus and ventromedial prefrontal cortex, a region implicated in value and state representations, also scaled to belief dosage. These findings illustrate a dose-dependent relationship between a thalamic circuit and nicotine-related beliefs in humans, a mechanism previously known to only apply to pharmacological agents." (Perl O. et. al. 2023)

This is incredible! We have long known that the placebo effect (a positive result from a perceived/fake drug or intervention) and the nocebo effect (a negative result from a perceived/fake drug or intervention) are real. These are beliefs based on an intentional telling of harm or benefit when the intervention is applied to the subject knowing that they may receive no drug. For example, I give you fake pill X but do not tell you whether it is real or fake. I also tell you that you will increase your ability to do X if you receive the drug. The placebo effect would state that you have a beneficial response because you believed that you received the actual drug even though you did not. The nocebo effect in this case would be the same but the effect would be negative to the fake pill.

This new study is importantly different in that all subjects received drug in the same dose without a placebo/no drug arm, but were told that they received differing doses. The responses then would be expected to be identical corresponding to the actual drug dose given. They were not. If the test subject was told that they received a high dose nicotine vape, they responded in kind acting like a high drug dose respondent by functional MRI testing. This is first of its kind research showing us that thoughts truly do create outcomes beyond what we previously believed at the cellular level.

"Importantly, beliefs about nicotine strength were represented by neural activities in the thalamus in a dose-dependent fashion, during value-based decision-making. Across individuals, the subjective perception of nicotine strength parametrically correlated with neural activities in thalamus. At the circuitry level, the functional coupling between thalamus and ventromedial prefrontal cortex also scaled parametrically to belief “dose”. Taken together, these findings demonstrate the precise mapping between beliefs and neural activities in a prefrontal-thalamic circuit.""Our study further reveals a granular mechanism that might account for these previous findings – that difference in neural activations can be triggered by manipulating one’s beliefs about nicotine intake (which likely acts as precursors of explicit habitual actions), as if the nAChRs receptors were activated by the presence of actual different dosages of nicotine. This implies that cognitive constructs such as beliefs and expectations can modulate fine-grained biological mechanisms in the human brain in a way that is similar to pharmacological agents."(Perl O. et. al. 2023)

The ventromedial prefrontal cortex is what is enhanced by many ADHD medicines and helps us focus on tasks. Many of these drugs help the prefrontal cortex orchestrate all of the brains functions to help maintain focus on the desired task at hand. If a child or patient is given the belief that drug X at this dose will have a great effect, odds are much higher that that effect will occur based on this research.

Bruce Lipton wrote a book a few decades ago about the role of thoughts in biology called the Biology of Belief. Give it a read.

It is high time that we as providers continue to beat the drum about positivity in all things especially when we discuss the response a patient will have to a given therapy.

Be positive,

Dr. M

Perl BioRxIV