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Medical Marijuana Disappoints Dementia

When is medical marijuana appropriate? Not in dementia, according to a new study. It suggests medical marijuana pills may not help treat behavioral symptoms of dementia, such as aggression, pacing and wandering. Get the details.
white plastic bottle with brown tablets of THC

The research is published in the online issue of Neurology®, the medical journal of the American Academy of Neurology. However, researchers did find that the drug dosage used in the clinical trial was safe and well-tolerated.

“Our study results are valuable since any firm evidence of the effectiveness and safety of medical marijuana in this disease area is scarce,” said study author Geke A.H. van den Elsen, MD, with Radboud university medical center in Nijmegen, the Netherlands. “Ours is the largest study carried out so far on evaluating this drug for behavioral symptoms of dementia.”

For the study, researchers randomly selected 50 participants with dementia and behavioral symptoms to receive 1.5 milligrams of medical marijuana or a placebo pill three times per day for three weeks. The medical marijuana pill contained tetrahydrocannabinol (THC), which is the main chemical involved in marijuana’s psychoactive effects. The main study measurement was change in scores on a test of behavioral symptoms called the Neuropsychiatric Inventory, assessed at the start of the study and after two and three weeks.

The test scores improved for both the medical marijuana and the placebo groups, but there was no significant difference between the scores for the two groups. There was also no difference between the two groups for participants’ quality of life, daily living activities or pain-related behavior and pain intensity.

Van den Elsen said improvements in the placebo group could be due to several factors, including attention and support from the study personnel, expectations of patients and caregivers and training of nursing home personnel.

People in the two groups had a similar number of mild and moderate side effects. There were no serious side effects in either group.

“Since the side effects were mild to moderate, it’s possible that a higher dose could be tolerated and could possibly be beneficial,” said van den Elsen. “Future studies are needed to test this. A drug that can treat the behavioral symptoms of dementia is much needed, as about 62 percent of dementia patients in the general community and up to 80 percent of nursing home residents experience these symptoms.”


The study was supported by the European Regional Development Fund and the Province of Gelderland. The drug was provided by Echo Pharmaceuticals, Weesp, the Netherlands.


The American Academy of Neurology, an association of more than 28,000 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer’s disease, stroke, migraine, multiple sclerosis, concussion, Parkinson’s disease and epilepsy.

For more information about the American Academy of Neurology, visit or find us on FacebookTwitterGoogle+ andYouTube.

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May 17, 2015 7:09 pm

AS Research Articles published in the lasts two years shows , MARIJUANA USE CAN LEADS TO A TSUNAMI OF COGNITIVE IMPAIRMENTS AND AD and OTHERS DEMENTIAS.
About the article above,published in the journal Neurology,did NOT shows None difference between the Placebo and Marijuana to calm the patients. But for sure, the patients under Marijuana Use are in High Risk to HASTENS theirs Cognitive,Mood and Behavior Disorders by the Increase of Risk of BRAIN SHIRNKAGE CAUSED BY MARIJUANA IN THE ELDERLY PEOPLE.
And as we can see bellow, scientific research articles Proved that Marijuana use (even once a week) can leads Teens,Adults, Middle Aged and Elderly NORMAL People, Directly to Cognitive Impairments and to Dementias. As we can see bellow,the researchers concluded that " Using Marijuana Even ONCE a Week" can Leads to so SIGNIFICANT NEGATIVE EFFECTS ON THE BRAINS of Teenagers and Young Adults, including COGNITIVE DECLINE, POOR ATTENTION AND MEMORY, AND DECREASED OF SIX POINTS IN IQ, Leading to PERFORMS about 18 PERCENT WORSE on Long-Term Memory tests THAN young adults WHO NEVER USED marijuana.What's more, the Longer they used the drug, the greater is the Hippocampus Shrinkage by Marijuana. And Brain Imaging (MRI and PET-SCAN) studies of regular MARIJUANA users have shown SIGNIFICANT SHRINKAGE OF THE BRAIN, ABNORMALITIES IN THE BRAIN’S GRAY MATTER, which is associated TO A REDUCTION IN INTELLIGENCE,nd the Brain Shrinkage (teens between 16"s and 19"s,was Permanent, REMAINED even after researchers controlled for major medical conditions, prenatal drug exposure, developmental delays and learning disabilities.
Then using our Rational Thinking , we can conclude: As MARIJUANA IT IS SO HARMFUL TO THE BRAINS of "normal" Teenagers and Young Persons,than, probably,the use of Marijuana can deeply Increases the chances to Triggers and Hastens Mild Cognitive Impairmentsand AD and others Dementias in "NORMAL" persons in middle age , over 40 to 50 years, earlier and deeper.
And as Marijuana cause Brain Shrinkage in young people , how HARMFUL CAN BE MARIJUANA TO THE "POOR BRAINS" OF AD and OTHERS DEMENTIA PATIENTS.It is a question of logic to governs with the support of it citizens to use the chance to STOPS the Risks of a Threatning "Pot" Cogninitive Impairment TSUNAMI.
Based in (we can find by the title in Google) :
1) Article published august 9,2014,with the title ,REGULAR MARIJUANA USE BAD FOR TEEN'S BRAINS about Public health Implications of Marijuana Legalization at the American Psychological Association’s 122nd Annual Convention
2) American Journal Nature World News , in the article published in 12 March 2015 ,based in the research from Northwestern University , with the title : ”MARIJUANA USE MAY LEAD TO POOR LONG-TERM MEMORY”(Hippocampus shirnkage by "cannabis" includes Neurons, Axons and Astrocytes-complete Damage to Hippocampus)

Reply to  Unknown
December 14, 2015 11:07 pm

This study is "overdosing" these trial patients!
When I placed my father on it, I only gave him a .5 gram dose "FOR THE WHOLE DAY!"
The second day I have given it to him, he spoke his first linear sentence within three years of absolute gibberish that was NOT BOUND within reality.

This was after eight years of him being with dementia (vascular)

After two hours had past since administering the "cookie," he called me over by saying this…

I came closer, with elation, but also, intrepidation, as he was often "reactive."
When moving in closer, he looked up into my eyes (NOT COMMON FOR MANY YEARS) and with a quivering lip and an exuberant stutter, he said this…


Before I could move my mouth out of lockjaw to express my regard from witnessing this miraculous event, he pointed to me and said one last thing…


So, if this study has deemed their being no benefits of cannabis toward "dementia," I'd have to say…


This article has pissed me off to the utmost degree!
Not only did the cannabis help my father back into a certain state of consciousness and communication, it completely decimated the agitation and involuntary jerky movements, often associated with Parkinson's.
Not only this, but it allowed him to walk again (for many months after he was becoming non-ambulatory) without his "mind" restricting his Inate ability to walk.
I believe the cannabis works in a number of benificial ways.
My father is non-ambulatory now, but he would have been "much" sooner without the cannabis.

May 17, 2015 9:29 pm

Carlos and I have been known to butt heads on many subjects … but we're squarely united on this one.


I've researched human studies and clinical trials on marijuana and related drugs (THC, CBD, etc) and there's every reason to believe they can be very harmful to many people including, as Carlos notes, to young, healthy people. According to a recent National Institute on Drug Abuse (NIDA) review, the adverse health effects of short-term marijuana use included impaired short-term memory, impaired motor coordination, increased risk of motor-vehicle accidents, altered judgment, and, in high doses, paranoia and psychosis. Long-term or heavy use resulted in altered brain development, dose-related cognitive impairments to attention, working memory, verbal learning, and memory functions (immediate recall, short-term memory, and memory retrieval) that persist and worsen with increasing years of regular use, lowered IQ, symptoms of chronic bronchitis, increased risk of anxiety and depression, increased risk of psychotic symptoms (delusions and hallucinations), and increased risk of chronic psychosis disorders (including schizophrenia) in persons with a predisposition to such disorders. It also exacerbates the course of illness once schizophrenia has been triggered. Some experts believe there is a direct, CAUSAL relationship with schizophrenia. Since marijuana use depresses the immune system, it is associated with increased rates of respiratory infections and pneumonia. Marijuana use is associated with vascular conditions that increase the risks of myocardial infarction, stroke, and transient ischemic attacks.

Older people are in general more likely to experience adverse drug events, due to a combination of age-related physiological changes (such as a decrease in lean body mass, and diminished renal and hepatic clearance) and a high prevalence of comorbidities, which can lead to polypharmacy and drug–drug interactions. Studies such as those discussed above focus on younger people. One would expect the elderly — especially the frail elderly with known neurological disorders — to react much more negatively to marijuana and the drugs derived from it.

May 17, 2015 9:34 pm

In studies on using marijuana or drugs derived from it to treat patients with diverse health problems, the range of responses for diverse symptoms has consistently been very wide, often with roughly half of patients being helped, and half being made significantly worse.

One of the reasons that clinical trial results have been so variable is that there are known gene mutations which can make the people who carry them much more sensitive to THC-induced psychoses and cognitive dysfunction.

Adverse side effects were also very common. During clinical trials of Marinol for the FDA-approved applications, for example, one-third of the patients reported adverse effects involving the central nervous system, including abnormal thinking, confusion, amnesia, depersonalization, hallucinations, paranoid reaction, anxiety/nervousness, ataxia, dizziness, euphoria, and somnolence. Please note that these were all NON-demented patients. As one review I read drily noted, to some it seems counterintuitive to treat a progressive cognitive disorder such as Alzheimer's with a treatment known to worsen cognitive impairment in healthy brains, such as marijuana or THC.

Marinol was also reported to cause cardiovascular problems, including tachycardia, palpitations, and, less frequently, hypotension. Seizures and seizure-like activity have been reported both during clinical trials and post-marketing.

In randomized, double blind, placebo controlled, crossover trial on using Marinol in Alzheimer's patients to help improve appetite, 15 Alzheimer's patients received 2.5 mg bid of the drug or placebo for six weeks. Of the 15, three experienced severe side effects (grand mal seizures, serious intercurrent infections) and had to drop out, and a fourth died of a heart attack. All four of these side effects are consistent with the known effects of THC. That's 25% of patients in the trial who suffered severe and/or fatal reactions.

November 24, 2015 10:36 pm

This is a joke! 1.5mg IS A JOKE! My mom is on three 10mg dronabinol per day. It has reversed her Alzheimer's. She has been on it for 20 months. IT MAKES ALL HER SYMPTOMS MUCH BETTER but doesn't help the memory much. Joel Taylor Wisconsin

February 9, 2016 7:21 pm

Well, it's certainly sad that it doesn't help, but we can't really expect marijuana to be some magical cure all.

April 4, 2023 1:13 pm

From what’s in the general media, you’d’ve thought this dangerous stuff is just candy…

B. Berger

B. Berger

This site was inspired by my Mom’s autoimmune dementia.

It is a place where we separate out the wheat from the chaffe, the important articles & videos from each week’s river of news. With a new post on Alzheimer’s or dementia appearing on the internet every 7 minutes, the site’s focus on the best information has been a help to many over the past 15 years. Thanks to our many subscribers for your supportive feedback.

The site is dedicated to all those preserving the dignity of the community of people living with dementia.

Peter Berger, Editor

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This site was inspired by my Mom’s autoimmune dementia.

It is a place where we separate out the wheat from the chaffe, the important articles & videos from each week’s river of news. With a new post on Alzheimer’s or dementia appearing on the internet every 7 minutes, the site’s focus on the best information has been a help to many over the past 15 years. Thanks to our many subscribers for your supportive feedback.

The site is dedicated to all those preserving the dignity of the community of people living with dementia.

Peter Berger, Editor

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