Human beliefs about drugs could have dose-dependent effects on the brain - ScienceDaily (Jan 3, 2024)

Drug-related beliefs can produce dose-dependent brain and behavior effects, according to Mount Sinai researchers studying nicotine-related expectations. Participants were nicotine dependent and were told that an e-cigarette would deliver low, medium, or high nicotine strengths, even though the actual nicotine level stayed constant. While doing a decision-making task during fMRI, the researchers found belief strength mapped onto neural activity in a way similar to pharmacology. The belief effect showed up in the thalamus and in functional connectivity between the thalamus and the ventromedial prefrontal cortex. The work suggests that subjective beliefs may help explain why people respond differently to drugs, and that targeting beliefs could potentially improve addiction treatment and other interventions such as psychotherapy, with future tests proposed for substances beyond nicotine including cannabis and alcohol.