Showing posts with label 13 reasons for marijuana. Show all posts
Showing posts with label 13 reasons for marijuana. Show all posts
Monday, August 31, 2026
Cannabis use linked to 37% higher stroke risk in massive study
Decide for yourself.
Wednesday, August 19, 2026
Inhaled cannabis reduces number of daily ectopic heart beats
Since I'm sure your doctor never prescribed marijuana post stroke you'll never hear of this.
My 13 reasons for marijuana use post-stroke. June 2014
Don't follow me, I'm not medically trained, and I don't have a Dr. in front of my name.
An ectopic heartbeat is an extra or early heartbeat that interrupts your normal heart rhythm. It can make your heart feel like it skipped a beat, paused, or gave a strong thump. Most extra beats are harmless, very common, and do not mean you have a serious heart disease.
Inhaled cannabis reduces number of daily ectopic heart beats
Key takeaways:
- Lower rates of ectopic heart beats on days in which habitual users inhaled cannabis vs. days of nonuse.
- Cannabis use in this cohort had no impact on daily steps, sleep duration or blood glucose.
Inhaled cannabis use was associated with acute reductions in ectopic heart beats vs. nonuse, mainly driven by reductions in premature atrial contractions, researchers reported.
The present study among habitual cannabis users identified certain acute effects of the drug on cardiac function, but no impact on daily steps count, sleep duration and glucose changes on days of use vs. nonuse was observed, according to data published in the Journal of the American College of Cardiology.
“Recreational cannabis is now legal in more than half the U.S. and is becoming more commonly used, but we know very little about the true health effects of the drug. At the same time, there is a growing interest in identifying modifiable risk factors that may influence risks of common heart rhythm disturbances. Prior work related to cannabis and arrhythmias has generally suggested harm, but has been conflicting,” Gregory M. Marcus, MD, MAS, cardiologist and Endowed Professor of Atrial Fibrillation Research in the division of cardiology at the University of California, San Francisco, told Healio.
The MARY-JANE trial was a prospective, randomized study conducted at the University of California, San Francisco. Researchers enrolled 108 habitual cannabis users who reported inhaled cannabis use at least once in the past month and 4 or more days within a week at least once in the past year. Participants had to be willing to abstain from cannabis use for at least 2 consecutive days over the 14-day trial period, according to the study methods.
Participants received a continuously recording ECG patch (Zio XT Patch, iRhythm), a Bluetooth-enabled, wrist-worn accelerometer and sleep monitoring device (Fitbit INSPIRE devices, Fitbit) and a Bluetooth-enabled continuous glucose monitor device (Dexcom G7, Dexcom).
Participants were randomly assigned via daily text message to either use or abstain from inhaled cannabis.
The primary outcome was daily cardiac ectopy, defined as total daily premature atrial and ventricular contractions. Mean daily steps, sleep duration per night and daily glucose changes were also evaluated, according to the study methods.
The researchers reported that although the mean age of study participants was 32 years, individuals representing each decade of life from age 21 into their 70s participated (59% women; 37% white).
Adherence to daily randomization was reported to be a challenge in the present study. However, the researchers wrote “it should not explain false positive results with regard to our prespecified primary endpoint or assessments of autonomic tone”
Inhaled cannabis was associated with a 9% reduction in ectopic beats (rate ratio [RR] = 0.91; 95% CI, 0.85-0.98; P = .02); a 10% reduction in daily premature atrial contractions (RR = 0.9; 95% CI, 0.82-0.97; P = .012); and no change in premature ventricular contractions (P = .83) compared with nonuse, according to the study.
Researchers reported that each inhalation of cannabis was associated with an approximately 2% reduction in ectopic beats (RR = 0.98; 95% CI, 0.97-0.99; P = .043).
“Contrary to our hypothesis, we failed to show that random assignment to use inhaled cannabis increased common cardiac ectopy. Of note, increasing frequencies of premature atrial contractions are an important predictor of atrial fibrillation, and those with more premature ventricular contraction frequencies have a higher risk for heart failure. In fact, we found a small decrease in cardiac ectopy, driven mainly by less premature atrial contractions, on days when participants were randomly assigned to smoke or vape cannabis,” Marcus told Healio. “At the same time and after excluding those ectopic beats from the continuous ECG data, we did see evidence of increased punctuated sympathetic activity on days randomized to cannabis, consistent with an increase in THC exposure on those days. Other methods to assess compliance suggested that participants generally followed their randomization assignment most of the time.”
Mean daily steps, sleep duration per night and daily glucose changes were not significantly different between inhaled cannabis use and nonuse, according to the study.
“This single study should not be considered sufficient to change clinical practice or recommendations, but should justify opening up future investigations and lines of inquiry as to how cannabis might actually have antiarrhythmic properties. It also challenges the notion that all inhaled smoke is the same, particularly given quite clear evidence that inhaled tobacco smoke has been consistently associated with more cardiac ectopy,” Marcus told Healio.
For more information:
Gregory M. Marcus, MD, MAS, can be reached at greg.marcus@ucsf.edu or X @gregorymmarcus.
Friday, August 14, 2026
Researchers Try to Tie Cannabis to Irregular Heartbeats, Opposite Turns Out True
Your competent? doctor immediately prescribed marijuana for all the benefits post stroke, right? NO? So UNEDUCATED AND INCOMPETENT? Your board of directors IS THAT FUCKING INCOMPETENT?
My 13 reasons for marijuana use post-stroke. June 2014
Don't follow me, I'm not medically trained, and I don't have a Dr. in front of my name.
Researchers Try to Tie Cannabis to Irregular Heartbeats, Opposite Turns Out True
Key Takeaways
- A randomized crossover trial examined the acute cardiovascular effects of inhaled cannabis among habitual users.
- There was a significant 9% reduction in premature heartbeats on days participants inhaled cannabis compared with days they abstained.
- The finding of reduced cardiac ectopy was questionable given major limitations of the trial, but the data did suggest that there was no increase in these heartbeats.
Defying expectations, regular cannabis users had fewer ectopic heartbeats on the days they reached for the joint or vape, a randomized crossover trial showed.
On days using cannabis, there was a significant 9% reduction in these extra or early heartbeats (median 13 per day on cannabis vs 13.8 per day off cannabis; rate ratio [RR] 0.91, 95% CI 0.85-0.98) among habitual cannabis smokers and vapers who had no history of clinically diagnosed cardiac arrhythmias.
While each cannabis inhalation was associated with a 2% reduction in ectopic beats (RR 0.98, 95% CI 0.97-0.99), Gregory Marcus, MD, MAS, of the University of California San Francisco, and colleagues noted that they were still wary of jumping too quickly to claim causality from this randomized trial.
"Given imperfect adherence, possible carryover, heterogeneous exposure, low baseline ectopy burden, and multiple exploratory analyses, the clinical implications remain uncertain," they wrote in the Journal of the American College of Cardiology.
"Ultimately, the most conservative interpretation of these data may be the clear evidence that inhaled cannabis did not increase cardiac ectopy," Marcus and team conceded.
Study participants were randomly assigned each day to inhale cannabis products or abstain completely via text messages for 14 days. Inhaled cannabis included smoked cannabis (joints, blunts, pipes, and bongs) and vaped cannabis. During follow-up, participants were equipped with a continuously recording ECG patch, a wrist-worn Fitbit activity tracker and sleep monitor, and a continuous glucose monitor for the first 10 days.
No significant differences were observed for step counts, sleep duration, or glucose levels.
"This study examined the acute effects of cannabis in people who use it regularly and was not designed to evaluate the long-term health consequences," Marcus cautioned in a press release. "The overall health effects of inhaled cannabis may still be net negative, but these findings suggest there may be something about cannabis that can teach us more about the biological mechanisms that produce premature atrial contractions. That knowledge could eventually lead to new approaches for preventing or treating abnormal heart rhythms."
Of note, the change in daily ectopy was driven by a decrease in daily premature atrial contractions (PACs), with a median of 7 on cannabis days versus 9.75 on off-cannabis days (RR 0.90, 95% CI 0.82-0.97), whereas premature ventricular contractions (PVCs) were unchanged on days using cannabis (median 3 vs 2.75; RR 1.01, 95% CI 0.91-1.12).
"To our knowledge, no previous randomized trial has demonstrated that any common exposure or lifestyle factor can influence PAC counts," Marcus and colleagues wrote.
The finding naturally leads to the question of whether lower PAC counts amount to tangible protection from a full-blown cardiac arrhythmia.
"Although the current study did not assess AF [atrial fibrillation] as an outcome, previous research has shown that PAC frequencies in the general population were the single most potent predictor of AF," the authors noted. "Indeed, eradication of PACs has been shown to prevent AF in select patients, and PACs, perhaps the most common arrhythmia, can themselves be bothersome and reduce quality of life."
The study included 108 adults who regularly smoked or vaped cannabis and had no history of clinically diagnosed cardiac arrhythmias.
At baseline, average age was 32 years, and 59% were women. None of the participants had diabetes, and 8% had hypertension. The most commonly reported methods of cannabis inhalation were joints (63%) and vape cartridges (57%), ranging in frequency of use from one to four times per month to three times or more per day. Fewer than one in three participants smoked tobacco or vaped nicotine concurrently.
There were a total of 713 days randomized to inhaled cannabis and 616 days randomized to abstinence.
Based on a combination of time-stamped Zio patch button presses at the time of cannabis use, daily surveys, and salivary mass spectrometry, Marcus and colleagues determined that participants followed instructions to inhale or avoid cannabis on most days, with adherence deemed as "moderate."
The authors acknowledged that there were plenty of caveats to the randomized study.
"For example, participants were not blinded to their exposure and were instructed to use their own cannabis products. This allowed for an assessment of the full inhaled cannabis experience that best recapitulated actual drug exposure and enhanced our ability to recruit and retain participants," they wrote. "However, this also resulted in substantial heterogeneity in the types and amounts of cannabis consumed and a consequent reduction in precision in analyzing associations with specific constituents."
Requiring participants to be frequent cannabis users may be a source of selection bias, they added, while the selection criteria further excluded anyone who had a history of AF or heart failure; had an implanted pacemaker or implantable cardioverter-defibrillator; had been prescribed beta-blockers, nondihydropyridine calcium-channel blockers, or Vaughn-Williams class 1 or 3 antiarrhythmic medications; or had a medical reason to avoid cannabis.
Importantly, the trial did not assess other effects of acute cannabis inhalation, nor did it collect data on alcohol consumption, a common co-intervention also linked to more PACs and PVCs.
The same research group previously reported that coffee consumption caused PVCs but not PACs.
Tuesday, July 28, 2026
The surprising ways cannabis may affect the aging brain
Since you're not likely to be a long term user post stroke maybe you'd rather hear of benefits than this Debbie Downer stuff!
My 13 reasons for marijuana use post-stroke. June 2014
Don't follow me, I'm not medically trained, and I don't have a Dr. in front of my name.
The surprising ways cannabis may affect the aging brain
Marijuana use seems to be more popular (or at least more openly talked about) than ever. Regardless of whether you’re on the gummy bandwagon, you might wonder how it really affects your brain after the buzz wears off.
About 15.4 percent of Americans older than 12 have used cannabis in the past month, according to 2024 data from the Substance Abuse and Mental Health Services Administration. That number has been increasing as new marijuana products hit the market and more states legalize its use, according to the Centers for Disease Control and Prevention.
Older adults — those 60 and older — are the fastest-growing group of cannabis users in the country. According to a 2022 study, adults over 60 who started using did so for medical reasons, including to treat pain and arthritis, sleep disturbances, anxiety and depression.
While more than three-quarters of those people found the cannabis either somewhat or very helpful, the question remains: What are the side effects? You may be particularly curious about brain effects, given concerns about cognitive decline. So what exactly does the research say?
Cannabis use is linked to worse working memory
This probably isn’t too surprising, but cannabis can affect your ability to retain information in the short term. This makes some intuitive sense to anyone who has tried it: “If you smoke cannabis, afterward, if you do a working memory test where you’re trying to maintain some piece of information, like a phone number or a short list of words, you’re less good at doing that while you’re acutely intoxicated,” said Joseph Schacht, associate professor of psychiatry and co-director of the Division of Addiction Science, Prevention and Treatment at the University of Colorado School of Medicine.
Related video: NIH-funded study finds midlife brain changes may help explain dementia risk (KYTX-TV Tyler-Longview)But lifetime use seems to have a similar effect. Consistent cannabis users tend to have lasting memory deficits compared with nonusers, he said. In a January 2025 study in JAMA Network Open, the largest of its kind, researchers looked at the effects of cannabis use on more than 1,000 adults ages 22 to 36 using brain imaging. Heavy lifetime users exhibited lower brain activity during a working memory task compared with nonusers after excluding recent users.It’s tied to changes in brain volume
Long-term cannabis use has also been associated with changes in brain volume. This is most pronounced in people who started using cannabis in adolescence, when the brain was still developing. “Cannabinoid exposure during that developmental window probably interferes with some of those normal brain development functions,” Schacht said.
Some research shows changes in the white matter of the brain in people who started using cannabis before the age of 16. White matter connects and facilitates communication among various regions of the brain. Younger users show more difficulty with cognitive tasks requiring executive function, such as inhibition control, linked to lower integrity of certain parts of white matter and higher behavioral impulsivity, said Staci Gruber, director of Marijuana Investigations for Neuroscientific Discovery at McLean Hospital in Belmont, Massachusetts, and associate professor of psychiatry at Harvard Medical School. Gruber is the study’s lead author.
In a 2026 meta-analysis of 77 studies in the journal Addiction, cannabis use was linked with reduced volume in the amygdala in particular, a region of the brain involved in processing and regulating emotions. But this study didn’t include information on when people started using the drug.
In adults ages 40 to 70 who began using cannabis after roughly 25 years of age, lifetime cannabis use is actually associated with greater brain volume, according to research published this year in the Journal of Studies on Alcohol and Drugs. That’s particularly true in areas of the brain with receptors for cannabinoids, the active compounds in cannabis that modulate things such as pain, mood and appetite. The study authors concluded this may be a sign of the “neuroprotective” benefits of cannabis in older adults, given that brain atrophy is common with age and is linked to cognitive decline and lower quality of life.
Those neuroprotective benefits could at least partly explain why cannabis use isn’t associated with dementia risk.
We need more data on how cannabis affects mood disorders
In a review in Lancet Psychiatry, researchers found no help or harm from specific cannabinoids with relation to a number of mood-related concerns, including anxiety and post-traumatic stress disorder. It also concluded there wasn’t enough data to study any potential effects on bipolar disorder or depression.
Gruber, however, noted that the study looked at either THC alone, CBD alone or a combination of THC and CBD, not the potential risks and benefits of the entire cannabis plant. (THC, or delta-9-tetrahydrocannabinol, is the psychoactive cannabinoid associated with the high caused by marijuana, while CBD, or cannabidiol, is a nonintoxicating cannabis compound.) “The idea that we would look primarily at single extracted compounds for things like anxiety is one that isn’t necessarily going to be as successful as when we look at multi-compound products,” she said. “The synergistic action of these things all together is significantly greater than the sum of its parts,” much like how sports teams are more successful with multiple players on the field.
Schacht notes that some people use cannabis as a way to mitigate symptoms without addressing the underlying cause. “As someone who has worked in addiction and substance use for a number of years, depression and anxiety are frequently reasons that people use a number of substances, such as cannabis, alcohol and nicotine,” he said. “Those drugs can be helpful in relieving those symptoms in the short term, but over the long term, I think it's fairly clear that they are not helpful and, in some cases, actually exacerbate the problem that led people to turn to them in the first place.”
Using marijuana as a teenager or young adult is linked to a greater risk of some serious mental health problems. “People who start using cannabis when they are young and who have any kind of a family history of psychosis or severe mental illness are at risk for developing psychosis and severe mental illness themselves because of the cannabis use,” Schacht said. The greatest association with psychosis and other severe mental illnesses is also typically strongest in the heaviest cannabis users.
Ultimately, Gruber said, more studies are needed — both larger studies and those that focus on the entire cannabis plant.
And, yet, researching cannabis is challenging because it is categorized federally as a Schedule I drug, meaning that, according to the U.S. Drug Enforcement Administration, it has “no currently accepted medical use and a high potential for abuse.” The risk of abuse decreases as the schedule number gets higher. The government’s strict regulations on studying these substances limit research opportunities. “It would be so much easier if people could use those things in the laboratory, for example, but we can’t generally do that,” Schacht said.
That would also help researchers investigate whether the method of cannabis delivery matters. More research is needed to know whether smoking, vaping or oral administration make any difference in cognitive (or other) effects.
Age matters when it comes to problematic cannabis use
To many people, other Schedule I drugs such as heroin and LSD sound much more concerning. But research suggests that 22 percent to 30 percent of people who use cannabis have cannabis use disorder, a type of substance use problem.
The risk of developing cannabis use disorder is higher in people who start using marijuana in adolescence and use it frequently. “It doesn’t mean that every single person who uses cannabis at an early age is going to have a problem, but our work and the work of others demonstrates that earlier onset of recreational cannabis use, along with more frequent and higher magnitude of use, is usually associated with worse potential outcomes,” Gruber said.
To her, future research should focus on whether the potential therapeutic benefits of cannabis can be harnessed without increasing the risk of harm to improve upon current standards of care. It will take time for research to catch up to the increasing popularity of this plant, Gruber said, but that very popularity points to some benefit: “If people didn’t yield something from it, why would they keep using this?”
In the meantime, without more research, it can be challenging for some people to decide whether cannabis might benefit them. “The best thing we can hope for is good, sound, empirical data that helps to drive individuals’ decisions as opposed to hearing somebody say ‘That should never be used,’” Gruber said. If you’re concerned about a specific aspect of your brain health, such as dementia risk, and how cannabis may affect you, consider talking to your doctor before trying legal products.
Thursday, June 18, 2026
7 unexpected takeaways from the newest research on cannabis and brain effects
Here's the Debbie Downer view of cannabis. enjoy reconciling this with the previous research.
My 13 reasons for marijuana use post-stroke. June 2014
Don't follow me, I'm not medically trained, and I don't have a Dr. in front of my name.
- marijuana
(163 posts to February 2011)
7 unexpected takeaways from the newest research on cannabis and brain effects
Stephen Lankenau has spent years studying how people use cannabis in everyday life. As director of Drexel University's Medical Cannabis Research Center, he has watched legalization spread, products grow stronger and daily use become increasingly common.
Yet one of the most basic questions remains surprisingly difficult to answer: How much cannabis is too much for the brain?
Social rituals around alcohol help define moderation - a beer after work, a glass of wine with dinner - and numerous studies have looked at safe alcohol limits. One federally commissioned paper published this month in the Journal of Studies on Alcohol and Drugs found that anything more than one drink a day increases mortality. But cannabis is entering mainstream life with few shared rules or routines. Researchers are trying to understand what problematic use looks like and whether new habits and cultural norms could help prevent it.
The question is becoming more urgent as cannabis use rises, particularly among younger adults, who tend to use it most heavily and are the most likely to experiment with increasingly potent products.
Doctors report increasing numbers of patients arriving in emergency rooms with confusion, paranoia, rapid heart beats, dizziness and other signs of cannabis intoxication. One study found that cases of cannabinoid hyperemesis syndrome, a condition involving severe, repeated vomiting, quadrupled among adults ages 18 to 35 between 2016 and 2022.
Recreational cannabis is now legal in 24 states and D.C. In 2002, about 25 million Americans reported using cannabis in the past year, according to the National Survey on Drug Use and Health. By 2023, that number had climbed to nearly 70 million. Daily or near-daily use has climbed even faster than occasional use, and adults over 35 are now among the fastest-growing groups of users.
Sorting out what constitutes "too much" is tricky. Most research has not been designed around recreational use, and today's consumers can choose from products ranging from high-potency vapes and concentrates to gummies, drinks and tinctures. But the science is advancing quickly. Some of the findings challenge long-held assumptions about the benefits of cannabis and health. And contemporary cannabis research is increasingly converging on three big variables: How often? How young? How strong is the drug?
1. Shifting potency
When marijuana entered mainstream American life in the 1960s, it quickly became attached to a familiar set of images: hippies, anti-war protests, youthful rebellion, experimentation. The debate over its effects was often blunt. Cannabis was either dangerous or liberating, mind-clouding or mind-expanding.
Interpreting cannabis research today is challenging because marijuana is far more potent than the products used by previous generations. In the 1970s and '80s, most cannabis flower contained relatively modest levels of THC - often in the low single digits. Today, many commercial products routinely exceed 20 percent THC. Concentrated products such as vape cartridges, waxes and "dabs" can reach 70 to 90 percent.
THC, or tetrahydrocannabinol, is the compound primarily responsible for cannabis's psychoactive effects, including intoxication, paranoia and, in some users, psychotic symptoms.
Some scientists think highly concentrated THC may produce larger dopamine surges and more profound disruptions in perception and salience processing - the brain's ability to determine what deserves attention.
A growing number of studies have linked frequent use of high-potency cannabis to altered brain connectivity, working-memory deficits and increased risk of psychosis-like symptoms, particularly among younger users and people with underlying vulnerabilities.
2. Overstated mental health benefits
Many adults, especially older ones, use cannabis for medical reasons such as to address pain, sleep or anxiety. But two recent studies - one in JAMA Internal Medicine and another in the Lancet - cast doubts.
The JAMA Internal Medicine report looked at previous studies related to PTSD, anxiety, depression, ADHD, bipolar disorder and other conditions, and found that the current evidence does not support the use of cannabis for any of them. On the other hand, the researchers warned, use of cannabis "demonstrates substantial risks of adverse effects."
The Lancet paper involved a systematic review and meta-analysis of 54 randomized controlled trials with nearly 2500 participants involving a wide range of mental health and other conditions. It found some evidence of a reduction in insomnia, tic or Tourette's syndrome, and autism spectrum disorder, but said "the quality of this evidence was generally low."
"Given the scarcity of evidence, the routine use of cannabinoids for the treatment of mental disorders … is currently rarely justified," the authors concluded.
3. Cognitive effects may vary by age
One of the more surprising shifts in cannabis research is that moderate use in adulthood may not impair cognition nearly as much as scientists once feared.
A widely discussed 2024 study published in JAMA Network Open, which examined middle-aged and older adults, found no major association between moderate cannabis use and cognitive decline across several domains after a year of use. But the researchers noted participants generally used lower-potency products and consumed them less than daily.
Carl Hart, a Columbia University psychologist who has studied cannabis and other drugs for decades, argues that the adult brain may be far more resilient to marijuana than many people assume. In one experiment, Hart and his colleagues offered adult participants the chance to earn money by performing well on a math test. Participants could choose whether to smoke cannabis beforehand.
More in Health
"Invariably they did not want to smoke because they wanted to make as much money as possible," Hart said.
In this study and others, Hart found that smoking cannabis had a minimal impact on accuracy of complex cognitive tasks. To Hart, the findings challenge one of the oldest assumptions about marijuana - that it inevitably drains motivation or ambition.
"Think of all the many people who take cannabis," he said, "there are some people not motivated to do jack, but that isn't because of cannabis. And there are a wide range of people who have done incredible things in the world while on cannabis. But the notion just won't die."
Other clues about what should be considered safe use come from a large 2025 study published in JAMA Network Open.
Researchers analyzing brain scans from more than 1,000 young adults ages 22 to 36 found that the clearest cognitive effects appeared among heavy lifetime users - people who had used cannabis more than 1,000 times. They showed reduced brain activity during tasks of working memory - which involves holding and using information in real time - while moderate users showed far fewer differences. The findings suggest that frequency and intensity of use may matter more than occasional consumption alone.
Notably, working memory was the only cognitive domain among seven tested that showed a statistically significant association with heavy cannabis use, suggesting that any effects on the brain may be more targeted than wide-reaching.
4. Teenage brains appear most vulnerable
Studies going back decades have found that adolescents who use cannabis regularly tend to earn lower grades and graduate from high school at lower rates, a pattern sometimes referred to as "amotivational syndrome."
We didn't see it in the adult brain. It was only the adolescent brain
Bertha Madras, a professor of psychobiology at Harvard Medical School
In February, a JAMA Health Forum study that followed roughly 460,000 adolescents ages 13 to 17 into young adulthood found that using cannabis in the previous year was associate with double the risk of later psychotic disorders and bipolar disorders when they reach age 26. In 2025, a JAMA Psychiatry study of young adults with cannabis use disorder found alterations in the dopamine-related brain system that were similar to what is seen in psychosis. These observation studies cannot prove causation, but the links have worried scientists.
Cannabis use disorder involves an inability to quit and psychological dependence and physiological withdrawal symptoms. The Centers for Disease Control and Prevention says 3 out of 10 people who use cannabis have it.
"All of these very serious neuropsychiatric symptoms are associated with motivation," said Bertha Madras, a professor of psychobiology at Harvard Medical School.
During puberty and early adulthood, neural connections are rapidly being formed, strengthened and pruned. In fact, brain-imaging research has linked cannabis use before age 16 to changes in white matter, the neural pathways that help different regions of the brain communicate.
One paper from 2021 found small declines in IQ in youths who used cannabis frequently.
Madras has conducted animal experiments involving adolescent rats and primates given daily marijuana exposure comparable to human use. She found pronounced inflammation in a part of the brain involved in emotional regulation and stress control.
"We didn't see it in the adult brain. It was only the adolescent brain," she said. "We began to speculate this observation may help explain why the drug has certain adverse effects on adolescents more than in adults."
Some studies suggest that cannabis use beginning at a younger age is associated with more persistent changes in executive function and IQ-related measures, but the findings remain subject to debate because it is difficult to fully account for socioeconomic, environmental, genetic and other confounding factors.
5. Chance of a cognitive rebound
The idea of taking a "tolerance break" - a temporary pause in cannabis use - has long been popular among regular users. Over time, the body can become less responsive to THC, the psychoactive compound in cannabis, meaning people may need larger amounts to achieve the same effects. Many long-term users notice that cannabis feels less potent than it once did, even as their consumption increases.
The field remains complicated because many studies are small and it can be difficult to separate the effects of cannabis from those of alcohol, nicotine and other substances.
A 2021 review published in Current Behavioral Neuroscience Reports found that some cognitive deficits associated with cannabis use - particularly those involving attention and working memory - may improve after sustained abstinence, especially among adults and lighter users. Similarly, a 2018 study in the Journal of the International Neuropsychological Society found that adolescents and young adults who abstained from cannabis for two weeks showed measurable improvements in attention.
Brain imaging studies have also provided encouraging signs. Several have found that altered patterns of brain connectivity in heavy cannabis users may partially normalize after a period of abstinence, particularly in networks involved in executive function, reward processing and emotional regulation.
These findings do not necessarily mean that all cannabis-related brain changes are reversible, nor do they establish how long recovery may take. But they suggest that for some people, reducing or stopping cannabis use may allow some cognitive function to rebound over time.
6. Signs of protecting older brains
Scientists are increasingly exploring whether certain cannabinoids might help protect aging brains by reducing inflammation and cellular stress - processes believed to play a role in diseases such as Alzheimer's and Parkinson's. The research is still early, and most of the evidence comes from laboratory studies rather than human trials.
A 2024 study from the Salk Institute drew attention for its focus on a little-known cannabinoid called cannabinol, or CBN, which forms as THC ages and breaks down over time.
The researchers studied a form of cell death that has been increasingly linked to neurodegenerative disease. In conditions such as Alzheimer's and Parkinson's, neurons often begin to die after their mitochondria - the tiny structures that produce energy inside cells - stop functioning properly.
Using mouse neurons, human brain-cell cultures and fruit-fly models, the Salk team found that CBN appeared to help protect neurons by preserving mitochondrial function and reducing oxidative stress, a damaging process associated with aging and neurodegeneration.
The findings generated excitement among some researchers because they suggest that stabilizing those cellular energy systems might someday help slow aspects of neurodegenerative decline. But scientists caution that the work remains far from proving that cannabis-derived products can prevent dementia or Parkinson's disease in humans.
7. Setting boundaries matters
Researchers studying cannabis have noted that while some users develop problematic patterns of use, most do not. This led scientists to ask what successful users do differently. The idea stems from the long-standing "drug, set and setting" theory, which argues that a person's experience with a substance is shaped not only by the drug itself but also by their mindset ("set") and the environment in which they use it ("setting").
In a paper published in December, Lankenau and colleagues looked a nine years of data on young cannabis users in Los Angeles.
They found that most participants fell into an "uncontrolled" group that used cannabis without consistently following self-imposed rules, while a smaller "controlled" group practiced rules such as not using before work or school and not driving while high. Those in the controlled group used cannabis less frequently and were less likely to show signs of problematic use.
A key takeaway, he said, is that moderation may depend less on the amount of cannabis someone uses than on whether they develop consistent boundaries around when, where and why they use it. The authors argue that understanding and promoting these "controlled use" practices could become an important public health strategy in the era of legal cannabis.
Lankenau argued that as cannabis becomes more widely available, public health agencies - not cannabis companies - need to take the lead in educating consumers about potency, dosing and potential risks. Because many people can now purchase high-potency products directly from dispensaries without consulting a physician.
"The more educated consumers are, the less negative effects we will see," Lankenau said.
Wednesday, May 6, 2026
Here's What Medical Marijuana Can Do for Older Patients
Your competent? doctor started prescribing you marijuana years ago, right!
My 13 reasons for marijuana use post-stroke. June 2014
Don't follow me, I'm not medically trained, and I don't have a Dr. in front of my name.
Here's What Medical Marijuana Can Do for Older Patients
An excerpt from Peter Grinspoon's book, "Aging Well with Cannabis
Older patients represent the group in which cannabis use is increasing most rapidly. The rates of use in this population doubled from 2005 to 2015 and roughly doubled once again from 2015 to 2018. As of 2023, roughly 7% of adults 65 and older reported using the drug in the past month. The earlier numbers might have been an undercount, however, as some people in this generation may not have felt comfortable admitting to using cannabis because of lingering stigma. But according to one study of patients ages 50 years and over, "Attitudes toward cannabis have changed over time with four of five survey respondents currently holding a favorable attitude."Older adults are discovering that cannabis helps them with many of the symptoms and discomforts of aging and, for some, may provide more relief than conventional pharmaceuticals -- and sometimes with fewer side effects (although cannabis itself isn't entirely free of potentially difficult side effects).
As we age, we accumulate diagnoses, specialists, and prescriptions. "Polypharmacy," the simultaneous use of five or more medications, is common, expensive, confusing, and dangerous. I have many primary care patients who are on 10 or more different medications. But some older patients are finding that they can reduce their reliance on traditional pharmaceuticals with the use of medical marijuana. Many of my patients have experienced improved symptom relief, relaxed mood, and a better health-related quality of life, as well as better-quality end-of-life care.
Chronic pain, anxiety, and insomnia, among many other symptoms, are epidemic in the 65-and-older crowd. With good intentions, doctors tend to throw medication after medication at these symptoms and ailments. The cost -- and side effects -- can be additive. In other words, when we prescribe a medication, it may alleviate one symptom but aggravate another. For example, we might prescribe a sleeping medication that results in worsened fatigue, balance, and memory. Rarely do we remember to stop, strip off, or pare down medications, let alone "de-prescribe" them. Our medical system is organized for doctors to do more for patients, even though sometimes "less is more." Often, we can help more by doing less and reevaluating treatments that have become unnecessary.
Medical cannabis is fundamentally different from most traditional pharmaceuticals in that it can help treat several symptoms at once. For example, it can help some patients with chronic pain, anxiety, and insomnia at the same time. Imagine how many fewer medicines a patient might need to take when medical marijuana comes on board. In addition, studies of medical cannabis consistently show that improved "health-related quality of life" is correlated with patient use of medicinal cannabis. At the end of the day, our health and the quality of our lives is all we have.
Conventional medical treatments for many conditions, including anxiety, insomnia, and chronic pain, can be particularly toxic to older patients. Take, for example, the case of chronic pain, which afflicts tens of millions of Americans. No doctor wishes to prescribe opioids, because they can cause falls, confusion, sedation, constipation, addiction, and delirium -- to name just a few problems.
Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin), naproxen (Aleve), or diclofenac (Voltaren) can harm -- or even kill -- in a variety of ways, including with bleeding, ulcers, heart attacks, and kidney failure. Indeed, we lose approximately 16,000 arthritis patients a year from overuse of NSAIDs. Just because a medication is sold over the counter doesn't mean it is without risks. Acetaminophen doesn't do much in the way of relieving chronic pain, and it can harm the liver. Likewise, the drug gabapentin (Neurontin), which is frequently prescribed to alleviate chronic pain, has a very modest benefit, but can make a patient feel brain-fogged and exhausted. These medications are more dangerous for older patients than they are for younger patients.
Older patients are discovering that while cannabis can help alleviate symptoms of chronic pain, it might also have a pleasant and helpful effect on their mood. This is especially true if cannabis is dosed properly -- it is imperative for patients to not take too much at first, to "start low and go slow." Taking a dose of cannabis that is too high can be a miserable experience and can even be dangerous.
Recent studies show a dramatic increase in symptom relief from cannabis in older populations, with relatively infrequent and mild side effects. In one 2018 study, Israeli researchers studied 2,736 medical cannabis patients who were over 65 years old. They found that a large majority of patients responded positively. After 6 months of treatment, 93.7% of the respondents reported improvement in their condition, and the reported pain level was reduced from a median of 8 to a median of 4 on a scale of 0-10. Most common adverse events were dizziness (9.7%) and dry mouth (7.1%). After 6 months, 18.1% stopped using opioid analgesics or reduced their dose.
These findings are consistent with my own clinical experiences with treating older adults with cannabis.
Having said that, cannabis is not for everyone. Some people have bad reactions, such as anxiety or dizziness. Other patients have fallen down or fainted, while others have medical conditions that make cannabis use even more dangerous. Some just don't like the feeling or find that it makes them too sleepy. And, as with all drugs and medications, cannabis doesn't work for all people. When it does work, it can be transformative.
Sunday, March 22, 2026
Cannabis study finds THC can create false memories
But do all the benefits of marijuana post stroke outweigh this? And your incompetent? doctor has no knowledge and really no say in this discussion!
My 13 reasons for marijuana use post-stroke.
Don't follow me, I'm not medically trained, and I don't have a Dr. in front of my name.
The latest here:
Cannabis study finds THC can create false memories
>Smoking cannabis may do more than make memories fuzzy. It may actually alter how memories form and are recalled.A new study from Washington State University found that people who consumed THC were more likely to recall words that were never shown to them and had more trouble completing everyday memory tasks, such as remembering to do something later.Published in the Journal of Psychopharmacology, the research provides one of the most detailed examinations to date of how cannabis influences memory. The results indicate that cannabis affects not only simple recall, like remembering a list of words, but also several forms of memory that people rely on throughout the day. These include remembering appointments, keeping track of conversations, and identifying where information originally came from. Researchers were also surprised to see no meaningful differences between participants who consumed 20 milligrams of THC and those who consumed 40 milligrams. This finding suggests that even moderate amounts of THC may significantly interfere with memory. Study Examines Multiple Memory Systems "Most previous studies have only looked at one or two types of memory, like recalling lists of words," said Carrie Cuttler, senior author of the study and an associate professor of psychology at WSU. "This is the first study to comprehensively examine many different memory systems at once, and what we found is that acute cannabis intoxication appears to broadly disrupt most of them." To investigate these effects, Cuttler and co-author Ryan McLaughlin, an associate professor in the Department of Integrative Physiology and Neuroscience at WSU, recruited 120 regular cannabis users. Participants were randomly assigned to vaporize placebo cannabis, 20 milligrams of THC, or 40 milligrams of THC in a double-blind experiment. After consuming the assigned substance, participants completed roughly an hour of memory tests. The assessments measured several types of memory, including verbal, visuospatial, prospective, source, false, episodic content, and temporal order memory.People who consumed cannabis performed significantly worse than those who received the placebo on most of the tests. In total, cannabis affected the majority of the memory measures, with significant differences appearing in 15 of the 21 tests.Cannabis Linked to False Memories and Source ConfusionThe most pronounced effects were seen in false memory and source memory, which help people accurately recall information and determine where that information came from.In one test, participants listened to lists of related words that were connected by a theme, but the central keyword tying them together was never spoken. Later, individuals who had consumed cannabis were more likely to say they remembered hearing words that had not been presented. "I found it was really common for people to come up with words that were never on the list," Cuttler said. "Sometimes they were related to the theme of the list, and sometimes they were completely unrelated."
Participants who used cannabis also had more difficulty identifying where previously learned information originated. Problems with source memory can make it harder to determine whether information came from a trusted source, a conversation, or something encountered online.
These kinds of memory distortions could have serious implications in situations where accurate recall is essential. For example, errors in memory or suggestive questioning during eyewitness interviews can influence how events are remembered.
Impacts on Everyday Memory Tasks
The researchers also observed impairments in prospective memory, which is the ability to remember to perform tasks in the future. This type of memory is involved in everyday responsibilities such as taking medication, attending meetings, or stopping at the store on the way home.
"These are things we rely on constantly in our day-to-day lives," Cuttler said. "If you have something you need to remember to do later, you probably don't want to be high at the time you need to remember to do it."
One form of memory called episodic content memory, which involves recalling personal experiences, did not show a significant effect in this study. Cuttler noted that additional research is needed before drawing firm conclusions about that type of memory.
Cannabis Use Is Growing but Research Gaps Remain
The study comes at a time when cannabis use is becoming increasingly common in states such as Washington. Even though legalization has expanded across North America, many short term cognitive effects of cannabis remain unclear.
One reason for the limited research is that cannabis is still classified as a Schedule I substance under federal law, which has historically restricted scientific study.
"We're living in a state where cannabis use is very common, but there's still a lot we don't know about its acute effects," Cuttler said. "The goal is to help people make informed decisions about the risks and benefits."
Story Source:
Materials provided by Washington State University. Note: Content may be edited for style and length.
Journal Reference:
- Carrie Cuttler, Ryan J. McLaughlin. Mapping the acute effects of cannabis on multiple memory domains: A randomized, double-blind, placebo-controlled study. Journal of Psychopharmacology, 2026; DOI: 10.1177/02698811261416079
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