#nicotinephysiology — Public Fediverse posts
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DATE: September 7, 2026 at 12:00PM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Cannabis use alters how the human brain processes nicotine, new research suggests
Recent non-daily use of cannabis might make the effects of nicotine feel more unpleasant at higher doses, without necessarily changing how often a person chooses to consume it. These findings help unravel the complex biological relationship between two commonly used substances and suggest that cannabis alters how the human body processes nicotine. The research was published in International Journal of Neuropsychopharmacology.
Cannabis and tobacco are frequently used together, and co-use is rising as legal cannabis markets expand and product varieties increase. Cannabis is a psychoactive plant containing compounds like delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Nicotine is the highly addictive chemical found in tobacco plants.
Studies show that combining these substances often makes it harder for people to quit. For example, a 2022 survey study found that people who increase their cannabis use have a harder time successfully quitting cigarette smoking. Animal research has hinted at the biology behind this, demonstrating that stimulating the brain’s cannabinoid receptors increases the motivation to seek out nicotine.
“Notably, cannabinoid and nicotinic receptors overlap in the brain circuits involved in reward and aversion, which in animal models helps explain the interaction between the two drugs,” Joao P. De Aquino, an assistant professor of psychiatry and director of the Pain and Addiction Interaction Neuroscience (PAIN) Lab at the Yale University School of Medicine, told PsyPost.
In humans, the interaction appears a bit more complicated. A study covered by PsyPost in 2018 showed that a large dose of cannabidiol actually stopped the typical increase in attention to cigarette cues during nicotine withdrawal. Another human laboratory experiment tested how smoking cannabis right before a tobacco cigarette altered immediate sensations, finding it changed subjective feelings but did not alter actual smoking behavior.
Despite this knowledge, it remained unknown how cannabis exposure directly changes a person’s immediate physiological and subjective reactions to pure nicotine. Most studies on human smoking involve tobacco cigarettes, which contain thousands of other chemicals that can cloud the results.
“The human evidence has been limited and sometimes contradictory,” De Aquino explained. “One reason is methodological: cigarette smoke contains thousands of compounds besides nicotine, which makes it difficult to isolate what nicotine itself is doing.”
The research, conducted at the Yale University School of Medicine, aimed to answer this question by isolating nicotine from tobacco smoke entirely. Gabriel P. A. Costa led the analysis under the senior authorship of Mehmet Sofuoglu and De Aquino.
“We analyzed two previously completed randomized, double-blind studies in which nicotine was administered intravenously, which let us isolate nicotine’s effects and directly ask whether recent cannabis use was associated with differences in how people responded to nicotine,” De Aquino said. “That is part of why we think carefully controlled human laboratory datasets remain valuable well beyond the aims of the trials that produced them.”
To examine the pure effects of nicotine, the researchers pooled data from 60 adults who regularly smoke tobacco cigarettes. Half of the participants had recently used cannabis, which was confirmed by a positive urine test. The other half had not used cannabis in the past 30 days and tested negative.
The team used intravenous nicotine administration, delivering the substance directly into the bloodstream through a catheter in the participant’s arm. In separate laboratory sessions, participants received a placebo consisting of saltwater, a low dose of nicotine (0.1 milligrams per 70 kilograms of body weight), and a higher dose (0.2 milligrams). These doses were designed to mimic the amount of nicotine absorbed from one to three puffs of a typical cigarette.
During the sessions, participants rated their subjective experiences on 100-point scales. They assessed stimulatory feelings, pleasurable feelings, and aversive feelings. Aversive effects included feeling anxious, feeling down, or experiencing a bad reaction to the drug. The researchers also tracked the participants’ heart rates and blood pressures.
Later in the sessions, participants completed a choice task. They were given multiple opportunities to choose between receiving the nicotine dose or the placebo again. This allowed the researchers to measure the primary reinforcement, or how much the participants actively wanted the drug. The statistical analysis controlled for factors like the participant’s sex and their baseline level of nicotine dependence.
Nicotine produced expected physiological changes, increasing heart rate and blood pressure across all participants. The drug also caused dose-dependent increases in subjective feelings of stimulation and pleasure. The cannabis-exposed group reported slightly higher pleasurable and stimulatory effects than the unexposed group, but the results were not statistically significant.
The most prominent difference emerged in how the groups experienced the aversive side effects of nicotine. At the higher 0.2 milligram dose, individuals with recent cannabis exposure reported substantially stronger unpleasant feelings compared to those without recent exposure. This amplified aversion was primarily driven by higher ratings of feeling down and experiencing bad drug effects.
“The difference in unpleasant effects at the higher dose was not simply a marginal statistical difference,” De Aquino noted. “It was relatively large by the standards of this type of laboratory study, and it grew with the nicotine dose.”
“Going from the lower to the higher nicotine dose, the differences in pleasure and stimulation stayed roughly flat, while the difference in unpleasant effects grew sharply,” he added. “That was the part we did not anticipate.”
Nicotine’s overall appeal relies on a delicate balance in the brain between reward pathways and aversion pathways. A person’s likelihood to keep smoking depends heavily on this balance. The findings suggest that cannabis might shift this scale, increasing the brain’s sensitivity to the unpleasant side effects of nicotine at higher doses.
“That suggests that recent cannabis use may shift the point at which nicotine’s unpleasant effects begin to build, rather than making people generally more sensitive to nicotine,” De Aquino explained.
Interestingly, the heightened negative feelings did not change the participants’ behavior during the choice task. Neither group showed a preference for the nicotine over the saline placebo in the laboratory setting. The physical cardiovascular reactions to the drug were also nearly identical between the two groups.
“Thus, recent cannabis use was linked to how unpleasant nicotine felt, but not to how often participants chose it in the laboratory,” De Aquino pointed out. “Our choice procedure was also short and ran under controlled conditions, so it may not capture what happens when people choose in ordinary life.”
The cannabis-exposed participants did show a distinct baseline clinical profile outside the laboratory. On average, they smoked about 40 percent fewer tobacco cigarettes per day (8.2 cigarettes compared to 13.4 cigarettes for the unexposed group). They also scored lower on standard tests measuring nicotine dependence.
“Those were pre-existing differences between the groups, not effects our study shows cannabis produced,” De Aquino emphasized.
As with all research, there are some caveats to consider. The study relied on a single urine test and self-reports to confirm cannabis use. This means the researchers did not have detailed information on how often participants used cannabis, what types of products they consumed, or the exact concentrations of compounds they ingested. Different cannabis profiles might interact with nicotine in distinct ways.
“To make more precise inferences we would need more granular data on the composition of the cannabis products themselves, including their potency, the THC-to-CBD ratio, how they were taken, and how often,” De Aquino said. Furthermore, “the trials whose data we leveraged excluded daily cannabis use and cannabis use disorder, so our findings are applicable to recent, non-daily cannabis use rather than heavy cannabis use.”
Because participants were not randomly assigned to use cannabis, the study cannot confirm that cannabis directly caused the heightened aversion to nicotine. It is possible that people who naturally find heavy nicotine doses unpleasant are simply more likely to use cannabis.
“Participants came into the studies with their existing patterns of cannabis and tobacco use, so we cannot tell whether cannabis changed their response to nicotine or whether people who respond differently to nicotine are also more likely to use cannabis,” De Aquino stated. He stressed that “our study does not show that cannabis makes it easier or harder to quit smoking. We did not measure smoking or quitting at all.”
Future studies tracking individuals before and after they begin using cannabis could help clarify whether the drug causes long-term changes in nicotine sensitivity. “One priority is to characterize cannabis exposure more precisely,” De Aquino noted, adding that “following people over time, ideally from before they start using cannabis, would also help establish which comes first.”
To better understand why this interaction happens, more investigation into the brain’s circuitry is needed. “One candidate neural substrate behind this aversive response to nicotine among people with recent cannabis exposure involves the habenula, a small brain region involved in nicotine’s unpleasant effects, along with alpha-5-containing nicotinic receptors,” De Aquino explained. “Imaging the brain during controlled nicotine administration, and studying genetic variation in those receptors, for example, could help test that possibility.”
This line of research ultimately aims to improve cessation strategies, such as the use of varenicline, a prescription medication used to help people quit smoking by reducing nicotine cravings and withdrawal symptoms. “Underneath all of this lies a clinically consequential question: whether treatments such as nicotine replacement therapy or varenicline may eventually need to be tailored for people who use both cannabis and nicotine,” De Aquino added.
“This is a reason to pursue clinical studies, not a finding that should change treatment today,” De Aquino concluded.
The study, “Recent cannabis exposure and acute nicotine effects: insights from randomized, double-blind, placebo-controlled intravenous nicotine studies,” was authored by Gabriel P. A. Costa, R. Ross MacLean, Mehmet Sofuoglu, and Joao P. De Aquino.
-------------------------------------------------
Private, vetted email list for mental health professionals: https://www.clinicians-exchange.org
Unofficial Psychology Today Xitter to toot feed at Psych Today Unofficial Bot @PTUnofficialBot
-------------------------------------------------
#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #CannabisNicotineInteraction #NicotineAversions #CannabisAndTobacco #NicotineResearch #CannabisResearch #Neuropharmacology #AddictionScience #YaleMedicine #Cannabinoids #NicotinePhysiology
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DATE: September 7, 2026 at 12:00PM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Cannabis use alters how the human brain processes nicotine, new research suggests
Recent non-daily use of cannabis might make the effects of nicotine feel more unpleasant at higher doses, without necessarily changing how often a person chooses to consume it. These findings help unravel the complex biological relationship between two commonly used substances and suggest that cannabis alters how the human body processes nicotine. The research was published in International Journal of Neuropsychopharmacology.
Cannabis and tobacco are frequently used together, and co-use is rising as legal cannabis markets expand and product varieties increase. Cannabis is a psychoactive plant containing compounds like delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Nicotine is the highly addictive chemical found in tobacco plants.
Studies show that combining these substances often makes it harder for people to quit. For example, a 2022 survey study found that people who increase their cannabis use have a harder time successfully quitting cigarette smoking. Animal research has hinted at the biology behind this, demonstrating that stimulating the brain’s cannabinoid receptors increases the motivation to seek out nicotine.
“Notably, cannabinoid and nicotinic receptors overlap in the brain circuits involved in reward and aversion, which in animal models helps explain the interaction between the two drugs,” Joao P. De Aquino, an assistant professor of psychiatry and director of the Pain and Addiction Interaction Neuroscience (PAIN) Lab at the Yale University School of Medicine, told PsyPost.
In humans, the interaction appears a bit more complicated. A study covered by PsyPost in 2018 showed that a large dose of cannabidiol actually stopped the typical increase in attention to cigarette cues during nicotine withdrawal. Another human laboratory experiment tested how smoking cannabis right before a tobacco cigarette altered immediate sensations, finding it changed subjective feelings but did not alter actual smoking behavior.
Despite this knowledge, it remained unknown how cannabis exposure directly changes a person’s immediate physiological and subjective reactions to pure nicotine. Most studies on human smoking involve tobacco cigarettes, which contain thousands of other chemicals that can cloud the results.
“The human evidence has been limited and sometimes contradictory,” De Aquino explained. “One reason is methodological: cigarette smoke contains thousands of compounds besides nicotine, which makes it difficult to isolate what nicotine itself is doing.”
The research, conducted at the Yale University School of Medicine, aimed to answer this question by isolating nicotine from tobacco smoke entirely. Gabriel P. A. Costa led the analysis under the senior authorship of Mehmet Sofuoglu and De Aquino.
“We analyzed two previously completed randomized, double-blind studies in which nicotine was administered intravenously, which let us isolate nicotine’s effects and directly ask whether recent cannabis use was associated with differences in how people responded to nicotine,” De Aquino said. “That is part of why we think carefully controlled human laboratory datasets remain valuable well beyond the aims of the trials that produced them.”
To examine the pure effects of nicotine, the researchers pooled data from 60 adults who regularly smoke tobacco cigarettes. Half of the participants had recently used cannabis, which was confirmed by a positive urine test. The other half had not used cannabis in the past 30 days and tested negative.
The team used intravenous nicotine administration, delivering the substance directly into the bloodstream through a catheter in the participant’s arm. In separate laboratory sessions, participants received a placebo consisting of saltwater, a low dose of nicotine (0.1 milligrams per 70 kilograms of body weight), and a higher dose (0.2 milligrams). These doses were designed to mimic the amount of nicotine absorbed from one to three puffs of a typical cigarette.
During the sessions, participants rated their subjective experiences on 100-point scales. They assessed stimulatory feelings, pleasurable feelings, and aversive feelings. Aversive effects included feeling anxious, feeling down, or experiencing a bad reaction to the drug. The researchers also tracked the participants’ heart rates and blood pressures.
Later in the sessions, participants completed a choice task. They were given multiple opportunities to choose between receiving the nicotine dose or the placebo again. This allowed the researchers to measure the primary reinforcement, or how much the participants actively wanted the drug. The statistical analysis controlled for factors like the participant’s sex and their baseline level of nicotine dependence.
Nicotine produced expected physiological changes, increasing heart rate and blood pressure across all participants. The drug also caused dose-dependent increases in subjective feelings of stimulation and pleasure. The cannabis-exposed group reported slightly higher pleasurable and stimulatory effects than the unexposed group, but the results were not statistically significant.
The most prominent difference emerged in how the groups experienced the aversive side effects of nicotine. At the higher 0.2 milligram dose, individuals with recent cannabis exposure reported substantially stronger unpleasant feelings compared to those without recent exposure. This amplified aversion was primarily driven by higher ratings of feeling down and experiencing bad drug effects.
“The difference in unpleasant effects at the higher dose was not simply a marginal statistical difference,” De Aquino noted. “It was relatively large by the standards of this type of laboratory study, and it grew with the nicotine dose.”
“Going from the lower to the higher nicotine dose, the differences in pleasure and stimulation stayed roughly flat, while the difference in unpleasant effects grew sharply,” he added. “That was the part we did not anticipate.”
Nicotine’s overall appeal relies on a delicate balance in the brain between reward pathways and aversion pathways. A person’s likelihood to keep smoking depends heavily on this balance. The findings suggest that cannabis might shift this scale, increasing the brain’s sensitivity to the unpleasant side effects of nicotine at higher doses.
“That suggests that recent cannabis use may shift the point at which nicotine’s unpleasant effects begin to build, rather than making people generally more sensitive to nicotine,” De Aquino explained.
Interestingly, the heightened negative feelings did not change the participants’ behavior during the choice task. Neither group showed a preference for the nicotine over the saline placebo in the laboratory setting. The physical cardiovascular reactions to the drug were also nearly identical between the two groups.
“Thus, recent cannabis use was linked to how unpleasant nicotine felt, but not to how often participants chose it in the laboratory,” De Aquino pointed out. “Our choice procedure was also short and ran under controlled conditions, so it may not capture what happens when people choose in ordinary life.”
The cannabis-exposed participants did show a distinct baseline clinical profile outside the laboratory. On average, they smoked about 40 percent fewer tobacco cigarettes per day (8.2 cigarettes compared to 13.4 cigarettes for the unexposed group). They also scored lower on standard tests measuring nicotine dependence.
“Those were pre-existing differences between the groups, not effects our study shows cannabis produced,” De Aquino emphasized.
As with all research, there are some caveats to consider. The study relied on a single urine test and self-reports to confirm cannabis use. This means the researchers did not have detailed information on how often participants used cannabis, what types of products they consumed, or the exact concentrations of compounds they ingested. Different cannabis profiles might interact with nicotine in distinct ways.
“To make more precise inferences we would need more granular data on the composition of the cannabis products themselves, including their potency, the THC-to-CBD ratio, how they were taken, and how often,” De Aquino said. Furthermore, “the trials whose data we leveraged excluded daily cannabis use and cannabis use disorder, so our findings are applicable to recent, non-daily cannabis use rather than heavy cannabis use.”
Because participants were not randomly assigned to use cannabis, the study cannot confirm that cannabis directly caused the heightened aversion to nicotine. It is possible that people who naturally find heavy nicotine doses unpleasant are simply more likely to use cannabis.
“Participants came into the studies with their existing patterns of cannabis and tobacco use, so we cannot tell whether cannabis changed their response to nicotine or whether people who respond differently to nicotine are also more likely to use cannabis,” De Aquino stated. He stressed that “our study does not show that cannabis makes it easier or harder to quit smoking. We did not measure smoking or quitting at all.”
Future studies tracking individuals before and after they begin using cannabis could help clarify whether the drug causes long-term changes in nicotine sensitivity. “One priority is to characterize cannabis exposure more precisely,” De Aquino noted, adding that “following people over time, ideally from before they start using cannabis, would also help establish which comes first.”
To better understand why this interaction happens, more investigation into the brain’s circuitry is needed. “One candidate neural substrate behind this aversive response to nicotine among people with recent cannabis exposure involves the habenula, a small brain region involved in nicotine’s unpleasant effects, along with alpha-5-containing nicotinic receptors,” De Aquino explained. “Imaging the brain during controlled nicotine administration, and studying genetic variation in those receptors, for example, could help test that possibility.”
This line of research ultimately aims to improve cessation strategies, such as the use of varenicline, a prescription medication used to help people quit smoking by reducing nicotine cravings and withdrawal symptoms. “Underneath all of this lies a clinically consequential question: whether treatments such as nicotine replacement therapy or varenicline may eventually need to be tailored for people who use both cannabis and nicotine,” De Aquino added.
“This is a reason to pursue clinical studies, not a finding that should change treatment today,” De Aquino concluded.
The study, “Recent cannabis exposure and acute nicotine effects: insights from randomized, double-blind, placebo-controlled intravenous nicotine studies,” was authored by Gabriel P. A. Costa, R. Ross MacLean, Mehmet Sofuoglu, and Joao P. De Aquino.
-------------------------------------------------
Private, vetted email list for mental health professionals: https://www.clinicians-exchange.org
Unofficial Psychology Today Xitter to toot feed at Psych Today Unofficial Bot @PTUnofficialBot
-------------------------------------------------
#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #CannabisNicotineInteraction #NicotineAversions #CannabisAndTobacco #NicotineResearch #CannabisResearch #Neuropharmacology #AddictionScience #YaleMedicine #Cannabinoids #NicotinePhysiology
-
DATE: September 7, 2026 at 12:00PM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Cannabis use alters how the human brain processes nicotine, new research suggests
Recent non-daily use of cannabis might make the effects of nicotine feel more unpleasant at higher doses, without necessarily changing how often a person chooses to consume it. These findings help unravel the complex biological relationship between two commonly used substances and suggest that cannabis alters how the human body processes nicotine. The research was published in International Journal of Neuropsychopharmacology.
Cannabis and tobacco are frequently used together, and co-use is rising as legal cannabis markets expand and product varieties increase. Cannabis is a psychoactive plant containing compounds like delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Nicotine is the highly addictive chemical found in tobacco plants.
Studies show that combining these substances often makes it harder for people to quit. For example, a 2022 survey study found that people who increase their cannabis use have a harder time successfully quitting cigarette smoking. Animal research has hinted at the biology behind this, demonstrating that stimulating the brain’s cannabinoid receptors increases the motivation to seek out nicotine.
“Notably, cannabinoid and nicotinic receptors overlap in the brain circuits involved in reward and aversion, which in animal models helps explain the interaction between the two drugs,” Joao P. De Aquino, an assistant professor of psychiatry and director of the Pain and Addiction Interaction Neuroscience (PAIN) Lab at the Yale University School of Medicine, told PsyPost.
In humans, the interaction appears a bit more complicated. A study covered by PsyPost in 2018 showed that a large dose of cannabidiol actually stopped the typical increase in attention to cigarette cues during nicotine withdrawal. Another human laboratory experiment tested how smoking cannabis right before a tobacco cigarette altered immediate sensations, finding it changed subjective feelings but did not alter actual smoking behavior.
Despite this knowledge, it remained unknown how cannabis exposure directly changes a person’s immediate physiological and subjective reactions to pure nicotine. Most studies on human smoking involve tobacco cigarettes, which contain thousands of other chemicals that can cloud the results.
“The human evidence has been limited and sometimes contradictory,” De Aquino explained. “One reason is methodological: cigarette smoke contains thousands of compounds besides nicotine, which makes it difficult to isolate what nicotine itself is doing.”
The research, conducted at the Yale University School of Medicine, aimed to answer this question by isolating nicotine from tobacco smoke entirely. Gabriel P. A. Costa led the analysis under the senior authorship of Mehmet Sofuoglu and De Aquino.
“We analyzed two previously completed randomized, double-blind studies in which nicotine was administered intravenously, which let us isolate nicotine’s effects and directly ask whether recent cannabis use was associated with differences in how people responded to nicotine,” De Aquino said. “That is part of why we think carefully controlled human laboratory datasets remain valuable well beyond the aims of the trials that produced them.”
To examine the pure effects of nicotine, the researchers pooled data from 60 adults who regularly smoke tobacco cigarettes. Half of the participants had recently used cannabis, which was confirmed by a positive urine test. The other half had not used cannabis in the past 30 days and tested negative.
The team used intravenous nicotine administration, delivering the substance directly into the bloodstream through a catheter in the participant’s arm. In separate laboratory sessions, participants received a placebo consisting of saltwater, a low dose of nicotine (0.1 milligrams per 70 kilograms of body weight), and a higher dose (0.2 milligrams). These doses were designed to mimic the amount of nicotine absorbed from one to three puffs of a typical cigarette.
During the sessions, participants rated their subjective experiences on 100-point scales. They assessed stimulatory feelings, pleasurable feelings, and aversive feelings. Aversive effects included feeling anxious, feeling down, or experiencing a bad reaction to the drug. The researchers also tracked the participants’ heart rates and blood pressures.
Later in the sessions, participants completed a choice task. They were given multiple opportunities to choose between receiving the nicotine dose or the placebo again. This allowed the researchers to measure the primary reinforcement, or how much the participants actively wanted the drug. The statistical analysis controlled for factors like the participant’s sex and their baseline level of nicotine dependence.
Nicotine produced expected physiological changes, increasing heart rate and blood pressure across all participants. The drug also caused dose-dependent increases in subjective feelings of stimulation and pleasure. The cannabis-exposed group reported slightly higher pleasurable and stimulatory effects than the unexposed group, but the results were not statistically significant.
The most prominent difference emerged in how the groups experienced the aversive side effects of nicotine. At the higher 0.2 milligram dose, individuals with recent cannabis exposure reported substantially stronger unpleasant feelings compared to those without recent exposure. This amplified aversion was primarily driven by higher ratings of feeling down and experiencing bad drug effects.
“The difference in unpleasant effects at the higher dose was not simply a marginal statistical difference,” De Aquino noted. “It was relatively large by the standards of this type of laboratory study, and it grew with the nicotine dose.”
“Going from the lower to the higher nicotine dose, the differences in pleasure and stimulation stayed roughly flat, while the difference in unpleasant effects grew sharply,” he added. “That was the part we did not anticipate.”
Nicotine’s overall appeal relies on a delicate balance in the brain between reward pathways and aversion pathways. A person’s likelihood to keep smoking depends heavily on this balance. The findings suggest that cannabis might shift this scale, increasing the brain’s sensitivity to the unpleasant side effects of nicotine at higher doses.
“That suggests that recent cannabis use may shift the point at which nicotine’s unpleasant effects begin to build, rather than making people generally more sensitive to nicotine,” De Aquino explained.
Interestingly, the heightened negative feelings did not change the participants’ behavior during the choice task. Neither group showed a preference for the nicotine over the saline placebo in the laboratory setting. The physical cardiovascular reactions to the drug were also nearly identical between the two groups.
“Thus, recent cannabis use was linked to how unpleasant nicotine felt, but not to how often participants chose it in the laboratory,” De Aquino pointed out. “Our choice procedure was also short and ran under controlled conditions, so it may not capture what happens when people choose in ordinary life.”
The cannabis-exposed participants did show a distinct baseline clinical profile outside the laboratory. On average, they smoked about 40 percent fewer tobacco cigarettes per day (8.2 cigarettes compared to 13.4 cigarettes for the unexposed group). They also scored lower on standard tests measuring nicotine dependence.
“Those were pre-existing differences between the groups, not effects our study shows cannabis produced,” De Aquino emphasized.
As with all research, there are some caveats to consider. The study relied on a single urine test and self-reports to confirm cannabis use. This means the researchers did not have detailed information on how often participants used cannabis, what types of products they consumed, or the exact concentrations of compounds they ingested. Different cannabis profiles might interact with nicotine in distinct ways.
“To make more precise inferences we would need more granular data on the composition of the cannabis products themselves, including their potency, the THC-to-CBD ratio, how they were taken, and how often,” De Aquino said. Furthermore, “the trials whose data we leveraged excluded daily cannabis use and cannabis use disorder, so our findings are applicable to recent, non-daily cannabis use rather than heavy cannabis use.”
Because participants were not randomly assigned to use cannabis, the study cannot confirm that cannabis directly caused the heightened aversion to nicotine. It is possible that people who naturally find heavy nicotine doses unpleasant are simply more likely to use cannabis.
“Participants came into the studies with their existing patterns of cannabis and tobacco use, so we cannot tell whether cannabis changed their response to nicotine or whether people who respond differently to nicotine are also more likely to use cannabis,” De Aquino stated. He stressed that “our study does not show that cannabis makes it easier or harder to quit smoking. We did not measure smoking or quitting at all.”
Future studies tracking individuals before and after they begin using cannabis could help clarify whether the drug causes long-term changes in nicotine sensitivity. “One priority is to characterize cannabis exposure more precisely,” De Aquino noted, adding that “following people over time, ideally from before they start using cannabis, would also help establish which comes first.”
To better understand why this interaction happens, more investigation into the brain’s circuitry is needed. “One candidate neural substrate behind this aversive response to nicotine among people with recent cannabis exposure involves the habenula, a small brain region involved in nicotine’s unpleasant effects, along with alpha-5-containing nicotinic receptors,” De Aquino explained. “Imaging the brain during controlled nicotine administration, and studying genetic variation in those receptors, for example, could help test that possibility.”
This line of research ultimately aims to improve cessation strategies, such as the use of varenicline, a prescription medication used to help people quit smoking by reducing nicotine cravings and withdrawal symptoms. “Underneath all of this lies a clinically consequential question: whether treatments such as nicotine replacement therapy or varenicline may eventually need to be tailored for people who use both cannabis and nicotine,” De Aquino added.
“This is a reason to pursue clinical studies, not a finding that should change treatment today,” De Aquino concluded.
The study, “Recent cannabis exposure and acute nicotine effects: insights from randomized, double-blind, placebo-controlled intravenous nicotine studies,” was authored by Gabriel P. A. Costa, R. Ross MacLean, Mehmet Sofuoglu, and Joao P. De Aquino.
-------------------------------------------------
Private, vetted email list for mental health professionals: https://www.clinicians-exchange.org
Unofficial Psychology Today Xitter to toot feed at Psych Today Unofficial Bot @PTUnofficialBot
-------------------------------------------------
#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #CannabisNicotineInteraction #NicotineAversions #CannabisAndTobacco #NicotineResearch #CannabisResearch #Neuropharmacology #AddictionScience #YaleMedicine #Cannabinoids #NicotinePhysiology