CBD’s unique neurological health benefits could be the reason why some people see it as an appealing alternative remedy to help with memory loss. Learn more. <strong>Dana Smith: </strong>Legalisation presents an opportunity to promote cannabis rich in a chemical that protects against its negative effects Current research suggest it can be both helpful and harmful to memory – here’s why.
CBD and Memory: Does CBD Affect Memory? – August 2022
CBD’s unique neurological health benefits could be the reason why some people see it as an appealing alternative remedy to help with memory loss. Results from previous scientific research and recent studies seem promising.
Several conditions can cause memory loss, especially in the elderly. Some conditions are treatable, while others, like Alzheimer’s, are not. Getting an immediate diagnosis and appropriate care is essential (6 ) .
For memory loss due to a traumatic brain injury (TBI) or caused by a condition, such as Alzheimer’s or dementia, the medications traditionally prescribed to treat symptoms include cholinesterase inhibitors and memantine. However, these medications can induce unwanted side effects, including nausea and headaches (7 ) .
CBD oil, meanwhile, does not produce those side effects. A study published in the British Journal of Pharmacology also demonstrated the anti-emetic (anti-nausea) effects of CBD, which is useful as a nausea and vomiting suppressant (8 ) .
Moreover, CBD’s anti-inflammatory and neuroprotective activities, as shown in a study published in PLoS One, make it an excellent potential alternative for improving brain function (9 ) .
Further longitudinal and robust studies are still required to derive high-quality evidence. However, results of scientific research conducted so far, suggesting CBD’s efficacy in improving cognition and helping with memory loss, are favorable.
Authors of a 2013 study examined the effects of cannabis use on memory function and found that cannabidiol (CBD) might possess anxiolytic (anti-anxiety) and antipsychotic effects (10 ) . Their data also showed that CBD did not impair cognition (11 ) .
The same authors reported that CBD might be protective of some aspects of memory function and might even reverse the deficits induced by tetrahydrocannabinol (THC), another primary cannabinoid (12 ) . THC is responsible for the intoxicating effects associated with the cannabis plant.
A 2017 study at the Australia’s University of Wollongong examined the effects of CBD on cognitive function in relevance to schizophrenia (13 ) .
The researchers of the said study found that CBD was effective in improving cognition for people with neurological disorders, neurodegenerative diseases, and neuro-inflammatory diseases, such as cerebral malaria and meningitis.
In another recent study , published in Frontiers in Pharmacology , researchers concluded that CBD might be a promising future avenue of research on neuroinflammation in response to traumatic brain injury (TBI) (14 ) . Learning and memory problems are among the most frequently reported symptoms following TBI (15 ) .
Memory loss caused by degenerative diseases, such as dementia and Alzheimer’s, is an area that CBD oil has been shown to have a potential positive impact.
In a 2017 study published in Frontiers in Pharmacology , CBD oil was shown to not only prevent the destruction of brain cells, but promote regrowth, or neurogenesis (16 ) .
The research mentioned above demonstrated CBD’s potential benefit for memory loss caused by conditions, such as dementia, Alzheimer’s, and traumatic brain injury, which may result in reduced cognitive function.
Other clinical trials have found that exposure to CBD for a prolonged period of eight months improves memory deficits related to social recognition (17 ) .
However, there may be individuals who may want to try CBD as a memory booster to help with forgetfulness.
Whether one is considering using CBD oil as a supplement to other medications for memory loss, or only as a memory aid, a consultation with a doctor before using CBD is essential.
CBD oil can interact with some medications, so caution is advised. Speak with a doctor who specializes in using CBD and other cannabis products in medical treatments.
How CBD Oil Works to Help with Memory Loss
Memory loss is often an initial sign of dementia and Alzheimer’s disease. Primarily, memory lapses may be mistaken for the typical forgetfulness that worsens as people grow old, or when they get stressed (18 ) .
CBD oil has been found to improve the health of those with dementia by lessening inflammation, reducing oxygenation, and stimulating and protecting the brain (19 ) .
The brain’s immune system has long been involved as a significant factor in the development of Alzheimer’s disease, particularly a specialized type of immune cell called microglia. The microglia cells help clear debris and toxic materials from the brain.
However, it appears that in Alzheimer’s, the immune cells do not function correctly or may even contribute directly to the disease process (20 ) .
The brain’s immune cells are also incapable of clearing blockages in dementia, and when situations like this occur, an inflammatory reaction is triggered. This inflammation has been shown to worsen symptoms of Alzheimer’s disease (21 ) .
CBD oil has been shown to reduce inflammation, with a 2017 study initially published in the Acta Biochimica et Biophysica Sinica Journal, noting that “CBD may be a promising candidate for Alzheimer’s disease therapy by inhibiting oxidative stress and neuroinflammation” (22 ) .
The inflammation that occurs in the brain due to Alzheimer’s disease is also called oxidation.As the oxidation process in the brain cells increase, functions such as memory decrease (23 ) .
However, CBD oil as antioxidant has been demonstrated to reduce this inflammatory effect, as indicated in a 2010 study on CBD oil and its effects on oxidative stress (24 ) .
The brain cell count in Alzheimer’s patients often undergoes a steady decline, reducing cognitive function and leaving destroyed pathways behind (25 ) .
CBD oil has been demonstrated in numerous studies to not only exhibit neuroprotective, anti-inflammatory and antioxidant properties but also promote neurogenesis, a process by which new neurons are formed in the brain (26 ) .
Newborn neurons at different maturation stages might make distinct contributions to learning and memory, according to a study published in Nature Reviews Neuroscience (27 ) .
The Pros and Cons of CBD Oil for Memory Loss
- CBD “is generally well tolerated with a good safety profile,” as the World Health Organization (WHO) states in a critical review (28 ) .
- CBD’s efficacy as a potential to help with memory loss has been shown in the numerous studies stated above.
- Studies are too limited to determine whether or not CBD is an effective treatment for conditions other than the ones approved by the U.S. Food and Drug Administration (FDA).
- As with the use of any natural chemical compound, there are risks involved in using CBD. According to the Mayo Clinic, possible side effects include drowsiness, dry mouth, diarrhea, fatigue, and reduced appetite (29 ) .
- CBD has been shown to alter how the body metabolizes certain medications, as a 2017 research published in the Cannabis and Cannabinoid Research journal reveals (30 ) .
Thus, consult with a doctor before taking CBD, especially when combining it with other prescription pharmaceuticals for memory loss.
- The lack of regulation makes it difficult to determine whether the CBD gummies, tinctures, patches, balms, and gelcaps contain what the product label claims.
A 2107 review published in the Journal of the American Medical Association revealed labeling inaccuracies among CBD products. Some products had less CBD than stated, while others had more (31 ) .
Speak with a physician experienced with cannabis use before starting a CBD regimen.
How CBD Oil Compares to Alternative Treatments that Help with Memory Loss
Some plant extracts, like Ginkgo biloba, lemon balm, and lavender, are often used as alternative treatments to help with symptoms of dementia and Alzheimer’s disease (32 ) .
Ginkgo biloba extract, derived from the leaves of the Ginkgo biloba tree, is often hailed as a memory aid.
However, according to a Mayo Clinic article, some studies have shown that the use of the extract provided little improvements in cognitive function for people.
Thus, most experts feel that the extract has not lived up to its early promise and do not recommend its use as a memory aid (33 ) .
Published in Nutrients , a 2014 study on lemon balm’s anti-anxiety effects showed that it might also help improve cognition and mood (34 ) .
Likewise, CBD might also help reduce anxiety, as results of a study published in the Journal of Psychopharmacology suggested (35 ) .
In a study published in the Journal of Korean Academy of Nursing in 2017, lavender oil was shown to reduce occurrences of aggressive behavior in dementia (36 ) .
Results of the study also demonstrated that a lavender aromatherapy hand massage program is effective on emotions and aggressive behavior of elderly with dementia of the Alzheimer’s type.
However, further research is required. Although massage therapies show promise, studies have not been longitudinal and rigorous enough to provide high-quality evidence.
Meanwhile, like the plant extracts mentioned above, CBD oil is a natural cannabis extract that has been shown in studies to help with memory loss. CBD in the form of tincture can also be used in aromatherapy and massage.
Using CBD oil may be an excellent alternative remedy to symptoms of disorders that affect memory, such as dementia and Alzheimer’s disease. As indicated in studies previously discussed, CBD’s neuroprotective, anti-inflammatory, and anti-anxiety properties may help protect the brain and improve cognition.
How to Choose the Right CBD for Memory Loss
Finding the CBD product that suits one’s needs and preference may require a little experimentation and some time. What works best for an individual may not work for someone else.
Still, regardless of the form of CBD product one chooses, he or she must employ careful consideration in choosing the best CBD oil that is right for him or her.
The following factors are essential to ensure the safety and reliability of the CBD products purchased:
- Research on the exact legal status and stipulations applicable to CBD in the area where it would be purchased and used.
- Purchase only from legitimate and reliable big brands. The majority of companies that manufacture the best CBD oil products grow their hemp from their farm, or they purchase from licensed hemp producers.
- When buying from an online store, do some research on product reviews first. When buying from a physical store or dispensary, check whether the store is authorized by the government to sell CBD.
- One important thing to look for in CBD products is certification codes. Several certification authorities approve certain products only after some thorough screening tests.
- Compare company claims about their products’ potency with that of the third-party lab reports.
Because of the unclear regulations in the United States and some problems with online product labeling, the authors of a Mayo Clinic article recommended the use of imported products from Europe (37 ) .
The same authors explained that Europe, aside from having a more established regulatory system for hemp, has more stringent requirements for low THC levels at less than 0.2% dry weight compared with the US requirement of less than 0.3% dry weight.
Still, consulting with a trusted medical professional experienced in CBD use is ideal before purchasing any CBD product.
CBD Dosage for Memory Loss
There is no standard for CBD oil when it comes to dosage. Because all people are different, there can be variations in the amount needed to find relief or improve memory.
CBD is mostly marketed as a supplement, not a medication. Currently, the U.S. Food and Drug Administration (FDA) does not regulate the safety and purity of dietary supplements.
Thus, CBD consumers cannot know for sure that the product they buy has active ingredients at the dose listed on the label. The CBD product may also contain other unknown elements.
Peter Grinspoon, MD, said in an article posted in Harvard Health, that they also do not know the most effective therapeutic dose of CBD for any particular medical condition (38 ) .
How to Take CBD Oil for Memory Loss (and Why)
The delivery method an individual chooses for taking CBD depends on one’s preference and lifestyle.
CBD Oil Capsules and Edibles
CBD oil capsules and edibles, such as brownies, gummies, and lozenges, are a convenient and straightforward way to take CBD oil, especially for beginners. They may be added to a current medication or vitamin regimen, or they may be taken with food and beverages.
This format is easy to include in one’s routine, and the dose is consistent. These advantages are helpful especially when memory is an ongoing concern.
Depending on one’s metabolism, the effects can last between 6 and 12 hours. However, the effects of the CBD oil could take at least 20 minutes to an hour to appear. Thus, CBD oil capsules and edibles do not provide immediate relief.
CBD Oil Tinctures or Drops
CBD oil tinctures or drops are a practical option for those who seek fast results and maximum dosage control.
Tinctures and drops are administered sublingually (under the tongue), through which the CBD oil is absorbed directly into the bloodstream.
Sublingual application allows for results to be experienced within 30 to 60 minutes after its use, and the effects can be felt for 4 to 6 hours.
Since tinctures and drops are convenient and easy to store and travel with, they can be effortlessly administered when needed.
However, one significant drawback to CBD oil tinctures and drops is the taste as not everyone appreciates the natural, earthy, and sometimes bitter flavor of hemp.
CBD Oil Vapes
CBD oil vapes are one of the accelerated ways to get CBD into the body since it enters the bloodstream through the lungs, without going through the digestive system.
When vaping CBD oil, effects can be felt in minutes. However, the effects last only for 30 minutes to an hour or two. Thus, it may not be the most effective option for improving memory.
Also, with vaping, it is difficult to determine precisely how much CBD is in each draw. Although labels for CBD oil vape products usually indicate the amount per inhale, everyone’s inhale is unique. Thus, getting the dose right requires a bit of experimentation at first.
A Closer Look at CBD
Cannabis sativa L. (Cannabaceae) is a type of cannabis that is one of the most recognized ancient plants. Sativa is Latin for “useful”, and it is a term that is commonly used in plant names.
Cannabis oil products include hemp oil and marijuana concentrates.
A hemp plant and a marijuana plant both belong to the plant genus cannabis. Cannabis is classified as a Schedule I drug in the United States but is legally accepted in 16 states and the District of Columbia for therapeutic purposes.
Cannabidiol (CBD) is an active ingredient in cannabis derived from the hemp plant and is commonly used to produce CBD hemp oil supplements.
CBD is non-intoxicating and non-addictive. CBD extracted from hemp is legal under U.S. federal law (39 ) .
One of the primary differences between CBD and THC lies in how they affect an individual who consumes them.
Although CBD and THC are similar in chemical structure, they do not share the same psychoactive effects. THC binds with the cannabinoid 1 or CB1 receptors in the brain and produces a sense of euphoria. THC is the cannabinoid that is mostly associated with marijuana or weed
CBD, however, binds inadequately to CB1 receptors. CBD can even disrupt the binding of THC and suppress its psychoactive effect, as researchers of a 2018 study published in the Neuropsychopharmacology Journal suggest. CBD, a non-psychoactive compound, does not induce the “high” associated with THC (40 ) .
THC and CBD are both found in the flowers, seeds, and stalks of both hemp and marijuana. Both cannabinoids naturally exist in cannabis plants in a broad range of proportions.
THC is most abundant in marijuana, while CBD is found in substantial quantities in hemp. The CBD oil ingredient that is found in most CBD oil products is extracted from the hemp plant.
CBD and the Immune System
The endocannabinoid system is interrelated with the immune system. To comprehend how CBD affects the body’s immune system, one must understand how the endocannabinoid system (ECS) works.
A 2008 study published in the Pharmacological Reviews Journal explored the endocannabinoid system and its regulatory functions in health and diseas e (41 ) .
The ECS is found in the central and peripheral nervous systems. It is a network of cannabinoids and CB1 and CB2 receptors, and it regulates most functions in the human body.
The ECS also acts as an immuno-cannabinoid modulator as it gathers and interprets signals from cannabinoids.
The body is capable of producing some cannabinoids on its own, which are called endocannabinoids. The ECS helps to manage functions such as immune-system responses, sleep, and pain, influencing a person’s physiology, mood and everyday experience.
Cannabinoids and terpenes work together to develop a cannabis strain’s distinctive flavor, resulting in a phenomenon known as the entourage effect.
Some neurotransmitters in the brain provide instructions for the body’s immune system and signal it when to activate its line of defense, where to engage it, and how strongly to involve it. Others are responsible for mood, emotions, and cognition.
Dementia, Alzheimer’s, and MIC
Disorders categorized under the general term “dementia” are caused by abnormal brain changes. These changes trigger a decline in thinking skills, also known as cognitive abilities, severe enough to impair daily life and independent function. Alzheimer’s is the most common cause of dementia and accounts for 60 to 80 percent of cases (42 ) .
Mild cognitive impairment leads to changes in cognition serious enough to be observed by other people but do not impact the individual’s ability to carry out everyday activities.
People living with MCI, especially MCI involving memory problems, are more likely to develop Alzheimer’s disease or other dementias than people without MCI.
A medical workup for MCI includes an assessment of one’s mental health using tests designed to evaluate memory, planning, judgment, and other critical thinking skills (43 ) .
For those suffering from memory loss, CBD oil may be an all-natural alternative to traditional medications or increasing concerns about impaired functioning.
Research into this all-natural compound from cannabis is still in the early stages. Even so, studies suggest that CBD has antioxidant, anti-inflammation, and analgesic properties, with the first two being crucial for memory preservation.
Still, before taking CBD, people are advised to consult with their doctor to avoid any adverse interactions that CBD may have with their current medications.
For more information on memory loss and forgetfulness, visit the National Institutes of Health ( NIH ) website (44 ) .
Esposito G, Scuderi C, Valenza M, et al. Cannabidiol reduces Aβ-induced neuroinflammation and promotes hippocampal neurogenesis through PPARγ involvement. PLoS One. 2011;6(12):e28668. doi:10.1371/journal.pone.0028668.
Schoeler T, Bhattacharyya S. The effect of cannabis use on memory function: an update. Subst Abuse Rehabil. 2013;4:11–27. Published 2013 Jan 23. doi:10.2147/SAR.S25869; Bhattacharyya S, Fusar-Poli P, Borgwardt S, et al. Modulation of mediotemporal and ventrostriatal function in humans by Delta9- tetrahydrocannabinol: a neural basis for the effects of Cannabis sativa on learning and psychosis. Arch Gen Psychiatry. 2009;66(4):442–451.
Crippa JA, Lacerda AL, Amaro E, Busatto Filho G, Zuardi AW, Bressan RA. Brain effects of cannabis – neuroimaging findings. Rev Bras Psiquiatr. 2005;27(1):70–78. Portuguese; Fusar-Poli P, Crippa JA, Bhattacharyya S, et al. Distinct effects of 9-tetrahydrocannabinol and cannabidiol on neural activation during emotional processing. Arch Gen Psychiatry. 2009;66(1):95–105; Bhattacharyya S, Morrison PD, Fusar-Poli P, et al. Opposite effects of delta-9-tetrahydrocannabinol and cannabidiol on human brain function and psychopathology. Neuropsychopharmacology. 2010;35(3):764–774; Morgan CJ, Schafer G, Freeman TP, Curran HV. Impact of cannabidiol on the acute memory and psychotomimetic effects of smoked cannabis: naturalistic study: naturalistic study [corrected] Br J Psychiatry. 2010;197(4):285–290.
Watt G, Karl T. In vivo Evidence for Therapeutic Properties of Cannabidiol (CBD) for Alzheimer’s Disease. Front. Pharmacol., 03 February 2017 | https://doi.org/10.3389/fphar.2017.00020 .
Deng, W., Aimone, J. & Gage, F. New neurons and new memories: how does adult hippocampal neurogenesis affect learning and memory? Nat Rev Neurosci 11, 339–350 (2010). https://doi.org/10.1038/nrn2822 .
Mayo Clinic. (2019, April19). Memory loss: When to seek help. Retrieved from https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/in-depth/memory-loss/art-20046326 .
CBDOilReview.org. Can CBD Oil Improve Memory? Retrieved from https://cbdoilreview.org/cbd-cannabidiol/cbd-oil-for-memory-improvement/ .
Parker LA, Rock EM, Limebeer CL. Regulation of nausea and vomiting by cannabinoids. Br J Pharmacol. 2011;163(7):1411–1422. doi:10.1111/j.1476-5381.2010.01176.x.
Esposito G, Scuderi C, Valenza M, et al. op. cit.
Crippa JA et al. op. cit.; Fusar-Poli P et al. op. cit; Bhattacharyya S et al. op. cit.; Morgan CJ et al. op. cit.
Schoeler T et al. op. cit.; Bhattacharyya S et al. op. cit.
Zuardi AW, Crippa JA, Hallak JE, Moreira FA, Guimarães FS. Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug. Braz J Med Biol Res. 2006 Apr; 39(4):421-9.
Osborne, A. L., Solowij, N. & Weston-Green, K. (2017). A systematic review of the effect of cannabidiol on cognitive function: relevance to schizophrenia. Neuroscience and Biobehavioral Reviews, 72 310-324. Retrived from https://ro.uow.edu.au/cgi/viewcontent.cgi?article=2037&context=ihmri .
Schurman LD, Lichtman AH. Endocannabinoids: A Promising Impact for Traumatic Brain Injury. Front Pharmacol. 2017;8:69. Published 2017 Feb 17. doi:10.3389/fphar.2017.00069.
Zec R. F., Zellers D., Belman J., Miller J., Matthews J., Femeau-Belman D., et al. (2001). Long-term consequences of severe closed head injury on episodic memory. J. Clin. Exp. Neuropsychol. 23 671–691. 10.1076/jcen.23.5.671.1247.
Watt G, Karl T. op. cit.
Alzheimer’s Society. Memory loss and dementia. Retrieved from https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/symptoms/memory-loss-dementia .
CBDOilReview.org. Alzheimer’s Disease and CBD Oil: Can It Help Dementia? Retrieved from https://cbdoilreview.org/diseases-conditions/cbd-oil-alzheimers-disease-dementia/ .
Alzheimer’s Society. Understanding how the immune system contributes to Alzheimer’s disease development. Retrieved from https://www.alzheimers.org.uk/research/our-research/research-projects/understanding-how-immune-system-contributes-alzheimers-disease-development .
CBDOilReview.org. op. cit.
Alexandre Vallée, Yves Lecarpentier, Rémy Guillevin, Jean-Noël Vallée. Effects of cannabidiol interactions with Wnt/β-catenin pathway and PPARγ on oxidative stress and neuroinflammation in Alzheimer’s disease. Acta Biochimica et Biophysica Sinica, Volume 49, Issue 10, October 2017, Pages 853–866, https://doi.org/10.1093/abbs/gmx073 .
CBDOilReview.org. op. cit.
Rajesh M, Mukhopadhyay P, Bátkai S, et al. Cannabidiol attenuates cardiac dysfunction, oxidative stress, fibrosis, and inflammatory and cell death signaling pathways in diabetic cardiomyopathy. J Am Coll Cardiol. 2010;56(25):2115–2125. doi:10.1016/j.jacc.2010.07.033.
CBDOilReview.org. op. cit.
Watt G, Karl T. op. cit.
Deng W et al. op. cit.
Expert Committee on Drug Dependence Fortieth Meeting. Cannabidiol (CBD) Critical Review Report. June 2018. Retrieved from https://www.who.int/medicines/access/controlled-substances/WHOCBDReportMay2018-2.pdf .
Bauer, B. (2018, Dec 20). What are the benefits of CBD — and is it safe to use? Retrieved from https://www.mayoclinic.org/healthy-lifestyle/consumer-health/expert-answers/is-cbd-safe-and-effective/faq-20446700 .
Iffland K, Grotenhermen F. An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies. Cannabis Cannabinoid Res. 2017;2(1):139–154. Published 2017 Jun 1. doi:10.1089/can.2016.0034.
Bonn-Miller MO, Loflin MJE, Thomas BF, Marcu JP, Hyke T, Vandrey R. Labeling Accuracy of Cannabidiol Extracts Sold Online. JAMA. 2017;318(17):1708–1709. doi:10.1001/jama.2017.11909.
Alzheimer’s Society. Aromatherapy, massage and dementia. Retrieved from https://www.alzheimers.org.uk/about-dementia/treatments/alternative-therapies/aromatherapy-massage .
Jonathan Graff-Radford, M.D. (2019, Apr 20). Ginkgo biloba: Can it prevent memory loss? Retrieved from https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/expert-answers/ginkgo-biloba-memory-loss/faq-20058119 .
Scholey A, Gibbs A, Neale C, et al. Anti-stress effects of lemon balm-containing foods. Nutrients. 2014;6(11):4805–4821. Published 2014 Oct 30. doi:10.3390/nu6114805.
Crippa JA, Derenusson GN, […], and Hallak JE. Neural basis of anxiolytic effects of cannabidiol (CBD) in generalized social anxiety disorder: a preliminary report. J Psychopharmacol. 2011 Jan;25(1):121-30. doi: 10.1177/0269881110379283. Epub 2010 Sep 9.
Lee SY. The Effect of Lavender Aromatherapy on Cognitive Function, Emotion, and Aggressive Behavior of Elderly with Dementia. J Korean Acad Nurs. 2005 Apr;35(2):303-312. https://doi.org/10.4040/jkan.2005.35.2.303 .
VanDolah H.J., Bauer B.A., Mauck K.F. Clinicians’ Guide to Cannabidiol and Hemp Oils. (2019) Mayo Clinic Proceedings, 94 (9) , pp. 1840-1851. DOI: https://doi.org/10.1016/j.mayocp.2019.01.003 .
Grinspoon P. (2019, Aug 27). Cannabidiol (CBD) — what we know and what we don’t. Retrieved from https://www.health.harvard.edu/blog/cannabidiol-cbd-what-we-know-and-what-we-dont-2018082414476 .
US FDA. (2020, Feb 13). FDA Regulation of Cannabis and Cannabis-Derived Products, Including Cannabidiol (CBD). Retrieved from https://www.fda.gov/news-events/public-health-focus/fda-regulation-cannabis-and-cannabis-derived-products-including-cannabidiol-cbd .
Boggs DL, Nguyen JD, Morgenson D, Taffe MA, Ranganathan M. Clinical and Preclinical Evidence for Functional Interactions of Cannabidiol and Δ9-Tetrahydrocannabinol. Neuropsychopharmacology. 2018;43(1):142–154. doi:10.1038/npp.2017.209.
Pacher P, Bátkai S, Kunos G. The endocannabinoid system as an emerging target of pharmacotherapy. Pharmacol Rev. 2006;58(3):389–462. doi:10.1124/pr.58.3.2.
Alzheimer’s Association. What Is Dementia? Retrieved from https://www.alz.org/alzheimers-dementia/what-is-dementia .
Alzheimer’s Association. Mild Cognitive Impairment (MCI). Retrieved from https://www.alz.org/alzheimers-dementia/what-is-dementia/related_conditions/mild-cognitive-impairment .
NIH. Memory loss and forgetfulness. Retrieved from https://www.nia.nih.gov/health/topics/memory-loss-and-forgetfulness .
Table of Contents
Nervous & Sensory System
Dr. Kimberly Langdon, MD
Kimberly Langdon, MD is a retired, board-certified obstetrician/gynecologist with 19-years of clinical experience. She graduated from The Ohio State University College of Medicine, earning Honors in many rotations. She then completed her OB/GYN residency program at The Ohio State University.
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Cannabis and memory loss: dude, where’s my CBD?
It isn’t often that science and pop culture overlap, but the two fields are in agreement when it comes to the familiar trope of the forgetful stoner.
A recent study published in Schizophrenia Bulletin is the latest to reveal the detrimental effects that cannabis can have on memory. The authors report that people dependent on the drug – both healthy individuals and patients with schizophrenia – show impairments in memory compared with healthy volunteers and non-smoking schizophrenia patients.
Even more striking, the cannabis-using groups had significant decreases in the volume of two brain areas that are important for processing rewards, learning and working memory – the thalamus and striatum – and these changes were linked to their memory problems. There was no evidence to connect cannabis use and schizophrenia – the authors simply compare the two groups. However, previous studies have found a higher prevalence of psychosis among regular cannabis smokers.
Reports of memory loss with long-term cannabis use are nothing new, and an influential paper published last year provided evidence that smoking marijuana has a deleterious effect on intelligence. In the investigation, the cognitive abilities of participants were tested several times over the course of 25 years. The researchers found that heavy cannabis users had significant decreases in intelligence and memory ability as they aged, not only compared with non-smokers, but also compared with their younger selves. Additionally, the earlier they started smoking pot, the bigger the cognitive decline.
Obviously these findings are worrying, especially given the recent spate of cannabis legalisations in states across the US and in countries such as Uruguay. However, before we all start worrying about the good people of Colorado and Washington, it might be helpful to look closer at what’s actually in the cannabis we’re smoking nowadays, and what ingredients are contributing to these cognitive deficits.
THC (tetrahydrocannabinol) is the primary psychoactive compound in cannabis and is what causes the subjective “high”. This includes changes in perceptual sensations, a feeling of contentedness and increased appetite. However, THC is also linked to many of the potential negative consequences of cannabis use, such as dependence, psychotic symptoms, and impaired memory and cognition.
Another important component, CBD (cannabidiol, which works by increasing natural cannabinoid levels in the brain) is associated with the calming, anti-anxiety effects of the drug. In addition, CBD is thought to protect against many of the potential negative effects of marijuana, including dependence, psychotic symptoms and cognitive impairments.
The THC concentration in cannabis has increased by as much as 12% over the past 30 years, making the drug much stronger than it used to be. At the same time, there has been a significant depletion of CBD, sometimes to levels as low as 0.1%. “Skunk”, as this new strain of high-THC/low-CBD marijuana is called, is flooding the illegal marijuana market, and it is this variety that is thought to be behind the rise in cannabis dependence diagnoses, links to schizophrenia, and cognitive deficits seen over the past decade.
The changing chemical make-up of cannabis appears to be partly accidental and partly deliberate. New strains are often bred to have higher levels of THC in them, increasing the drug’s potency. However, modern growing techniques have also affected these chemical levels. For example, illegal growers have turned to indoor marijuana farms to avoid detection. Growing cannabis locally in such farms also circumvents the need to import the drug, and guarantees a more reliable harvest. However, the 24-hour lighting used in these farms inadvertently reduces CBD levels in the plant. Thus, these new strains are not only bred for higher potency, with elevated THC content, they are also lacking the protection provided by CBD against the drug’s negative effects.
It should be noted that the majority of research into cognitive deficits and cannabis use has focused on heavy or dependent users, and there’s little evidence that occasional smokers show any of the problems mentioned above. But with the recent changes in drug policy, the chances are that more people will be smoking cannabis than ever before, and the more potent and more popular high-THC/low-CBD marijuana that is available today will increase their risk of dependence.
The recent legalisation of recreational and medicinal marijuana in parts of the US has the potential to reduce significantly the harms caused through incarceration or criminal records for minor drug-related offences. However, it also provides an opportunity to reduce the cognitive and psychiatric harms linked to cannabis use. With this shift in drug policy, it is now possible for states to monitor the commercial production of cannabis, regulating the levels of THC and CBD present in the drug. To facilitate this, they could force growers to use strains with higher levels of CBD, and revert to more old-fashioned farming methods that don’t use round-the-clock lighting.
These changes could help protect individuals from the damaging effects of the drug, prevent the development of dependence in new users, and maybe even help our favorite Hollywood stoners remember where they left their car.
Does cannabis really affect memory? Here’s what research currently says
Elizabeth Hughes receives funding from National Institute for Health Research.
Ian Hamilton does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
University of Leeds provides funding as a founding partner of The Conversation UK.
University of York provides funding as a member of The Conversation UK.
THC and CBD, both cannabis compounds, have very different effects on the brain. Dmytro Tyshchenko/ Shutterstock
Cannabis use has long been associated with memory loss. But until now, this notion was largely anecdotal. As researchers begin to look into cannabis and the effect that it has on human health, they’re beginning to better understand the effect it has on the human brain – and whether cannabis really does impair memory.
Memory is divided into both short-term and long-term memory. Short-term memory is where immediate events are temporarily stored, whereas long-term memory is where information is stored indefinitely.
Current evidence shows that cannabis intoxication may temporarily alter or distort short-term memory processing. This seems to be caused by compounds in cannabis that disrupt neural signalling when binding to receptors responsible for memory in the brain. Interrupted short-term memory can indeed impact on learning, and may also cause loss of interest or problems with concentration.
However, early research also shows that cannabis could have a positive impact on neurodegenerative diseases that affect memory, such as Alzheimer’s, Huntington Chorea, and epilepsy. In mainly animal studies, when researchers used components found in cannabis, they found it could slow or even prevent the advance of these diseases – essentially through the creation of neurons.
These apparently paradoxical effects from the same drug are best explained by two chemicals found in cannabis. Namely delta 9-tetrahydrocannabinol (THC) and cannabidiol (CBD). We all have naturally occurring cannabinoid receptors in our brains. THC is able to effectively bind to these receptors, creating euphoric effects. However CBD can interfere with this binding process, which dampens the feeling of euphoria.
Different ratios of these two chemicals are found in various types of cannabis. Consuming a cannabis product with THC but no CBD increases the risk of developing mental health problems, such as psychosis. However, CBD could actually be used to treat psychosis.
Cannabis with higher levels of THC and lower, or negligible, amounts of CBD appear to have a detrimental effect on short-term memory, particularly in adolescents. The main problem is their ability to retain and recall information. Fortunately this is not permanent.
But these recent discoveries about the role of THC and CBD in cannabis show that we can no longer simply say cannabis itself causes psychosis, or is detrimental to memory. Rather, it might be the type of cannabis, and the compounds it contains, that may have specific risks or benefits.
And while there’s little doubt that some people who use cannabis do experience impaired memory, establishing that cannabis is the cause is tricky. One reason for this is because it’s difficult to rule out the impact of other drugs that people may have used – and whether these drugs contributed to this memory impairment. For example, alcohol misuse can also cause brain damage and memory loss. Another obvious problem when researching this is when asking people with impaired memory to recall their past drug use and any associated problems. Their ability to recall these details could be compromised.
Recent research even suggests that any memory impairment associated with using cannabis can be reversed when people stop using cannabis. This effect was seen mainly in those who used cannabis at least once a week.
Just as higher doses of alcohol can potentially cause brain damage, higher doses or more frequent use of cannabis may also cause long-term memory problems – the ability to learn effectively and the ability to concentrate on a task for example. Some people will use both alcohol and cannabis, often at the same time, which may both worsen the potential impact on memory.
New research also suggests that it’s cannabis, rather than alcohol, that’s responsible for damage to developing teen brains. Though alcohol can destroy or severely damage brain neurons and their signalling functions, this study showed cannabis actually changes the neural brain tissue responsible for memory. But this change can be reversed within a matter of weeks if a person abstains. Though surveys suggest fewer young people are using both cannabis and alcohol, those teenagers that do use cannabis use it twice as frequently.
Frequent cannabis by teens may impact their memory and ability to concentrate. mooremedia/ Shutterstock
Research shows that young, frequent users of cannabis have thinner temporal and frontal cortices, which are both areas that help process memory functioning. Memory is a critical aid to learning and study – but cannabis doesn’t just effect memory, it can also reduce motivation to learn. This dual influence reduces a young person’s engagement in education and their ability to perform.
However, using cannabis later in life (age 50 and over) appears to have only a moderate impact on cognitive functioning, including on memory. These modest declines are not fully understood, and there is a lack of high quality research in this area. That will need to change as it’s not just young people that use cannabis. As more countries legalise cannabis, older people might also want to try it.
While there is likely to be no great harm to a person’s memory if they experiment with cannabis, current research seems to agree that the more frequent the use, the greater the risk. Though there is still a lot that researchers don’t yet know about cannabis use on memory, current evidence suggests that any memory impairment can be reversed if a person abstains from use.