People’s beliefs about medications can affect the potency of a substance and how their brains respond, according to the findings of a new study.
The study, conducted by researchers from Mount Sinai and published in Nature Mental Health, focused on the participants’ beliefs about nicotine, specifically about how much they believed they were being given.
The researchers said the effects they observed were similar to the dose-dependent effects of medications.
The results have far-reaching implications for the understanding and treatment of mental disorders.
Findings from the study could help scientists understand how a person’s beliefs affect mechanisms in the brain and the role they may play in addiction. They could also help scientists better understand the way treatments using medications and other types of therapies could be enhanced by leveraging the power of our beliefs.
“Beliefs can have a powerful influence on our behavior, yet their effects are considered imprecise and rarely examined by quantitative neuroscience methods,” Xiaosi Gu, senior author of the study, said in a statement.
“We set out to investigate if human beliefs can modulate brain activities in a dose-dependent manner similar to what drugs do, and found a high level of precision in how beliefs can influence the human brain. This finding could be crucial for advancing our knowledge about the role of beliefs in addiction as well as a broad range of disorders and their treatments.”
Ms. Gu has a doctorate in neuroscience and is an associate professor of psychiatry and neuroscience at the Icahn School of Medicine at Mount Sinai in New York,
To further examine this relationship, nicotine-dependent study subjects were told one of three things about the levels of nicotine in an electronic cigarette they were given: whether the level was low, moderate, or high. In fact, the level of nicotine remained the same. After vaping, the participants had brain imaging via fMRI (functional magnetic resonance imaging) while performing a task known to stimulate parts of the brain activated by nicotine.
The scans showed that the thalamus—which binds to nicotine in the brain—responded in a dose-dependent manner that aligned with the study participants’ beliefs about the nicotine’s strength.
Until now, this effect was thought to apply only to medications.
The researchers also found that the participants’ beliefs had dose-dependent effects on how two parts of the brain connect—the thalamus, which acts as a relay station, processing all information between the brain and body, and the ventromedial prefrontal cortex—a region of the brain that contributes to regulating emotions and is considered important for decision-making and beliefs.
“Our findings provide a mechanistic explanation for the well-known variations in individual responses to drugs,” Ms. Gu said, “and suggest that subjective beliefs could be a direct target for the treatment of substance use disorders. They could also advance our understanding of how cognitive interventions, such as psychotherapy, work at the neurobiological level in general for a wide range of psychiatric conditions beyond addiction.”
Computational Psychiatry
Ms. Gu is one of the world’s leading researchers in a new field known as computational psychiatry. Her laboratory website describes computational psychiatry as “a new interdisciplinary field which seeks to characterize mental disorders in terms of aberrant computations at multiple scales.”
“In recent years the field of human neuroscience, particularly functional neuroimaging, has begun to address the underlying neurobiology of changes in brain function related to psychiatric disease,” it reads.
A review article in Nature Neuroscience describes computational psychiatry as combining “multiple levels and types of computation with multiple types of data in an effort to improve understanding, prediction, and treatment of mental illness.”
Ms. Gu’s research “examines the neural and computational mechanisms underlying human beliefs, emotions, decision making, and social interaction in both health and disease,” according to the Mount Sinai website.
Applications in Clinical Practice
Ms. Gu addressed another way that her team’s findings could be applied in clinical practice.
“The finding that human beliefs about drugs play such a pivotal role suggests that we could potentially enhance patients’ responses to pharmacological treatments by leveraging these beliefs,” she said.
Ms. Gu and her research team have uncovered a vital piece of the puzzle of how our subjective beliefs affect the brain and behavior. Their insights could lead to a greater understanding of how mental health disorders develop and the role a patient’s beliefs may play in his or her treatment.
“We’re interested in testing the effects of beliefs on drugs beyond nicotine to include addictive substances like cannabis and alcohol, and therapeutic agents like antidepressants and psychedelics,” Ms. Gu said.
“It would be fascinating to examine, for example, how the potency of a drug might impact the effect of drug-related beliefs on the brain and behavior, and how long-lasting the impact of those beliefs might be. Our findings could potentially revolutionize how we view drugs and therapy in a much broader context of health.”