CBD May Protect Against and Relieve Brain Injury Symptoms
During the past several years, public awareness about brain injuries has increased — thanks in part to several former professional athletes, military veterans, and accident survivors who are speaking out about effects of brain injuries, as well as a variety of brain injury awareness campaigns conducted by athletic and government organizations. 
Researchers also have been conducting studies to learn more about brain injuries, so they can understand the causes and develop new, more effective treatments. One brain injury treatment that is showing promise is cannabidiol, or CBD, which is a non-intoxicating cannabinoid molecule produced by cannabis.
What is a brain injury?
Traumatic brain injury (TBI) is a condition that occurs when a head injury, such as a bump, blow, or jolt, causes your brain to slam into the inside of your skull, which results in brain damage.
When your brain is injured, it releases neurotransmitters and chemicals that cause inflammation, blood vessel injury, chemical imbalances, tissue damage, and cell death. These brain responses are called a “secondary injury cascade” and are responsible for many of the neurological problems associated with TBI.
Although a severe TBI can be deadly or cause lifelong complications, even a mild TBI — which is commonly called a concussion — can cause symptoms that can last for days or weeks.
Repeated TBIs can cause a buildup of Tau protein, which can lead to a degenerative neurological condition called chronic traumatic encephalopathy (CTE). CTE can have a devastating impact on individuals and their families because it can cause a variety of symptoms that affect memory, emotions, behavior, movement, and mental functioning.
CBD May Offer Neuroprotective Benefits
In 1998, researchers published the results of a study on rats that demonstrated the neuroprotective benefits of CBD and tetrahydrocannabinol (THC), which are two of the cannabinoids found in cannabis.  Although more research is required to fully understand the neuroprotective effects of CBD, recent studies have shown that CBD activates the cannabinoid receptors in your brain that are part of your body’s natural endocannabinoid system.
A 2011 study of mice found that endocannabinoid levels are elevated during and after a TBI, which suggests that the endocannabinoid system plays an important neuroprotective role. 
Other animal studies also have shown that activating the cannabinoid receptors in your brain may help to limit nerve cell damage and promote healing by enhancing blood flow to the brain.  In a 2002 study, researchers found that mice that were genetically engineered to lack CB1, a cannabinoid receptor found in the brain, had more severe brain damage and cognitive deficits after a TBI when compared to mice that had the CB1 receptor.
Activating another cannabinoid receptor in the brain, called CB2, has been shown to promote the creation of new brain cells, as well as regulate inflammation after brain injury. A 2014 animal study found that mice that were genetically engineered to lack a CB2 receptor had worse outcomes after TBI when compared to mice that had a CB2 receptor. The study also found that the lack of a CB2 receptor impaired the creation of new brain cells.
And, CBD may also affect your glial cells, which insulate your neurons and facilitate your brain’s immune response after injury. Research shows that CBD seems to have the strongest effect on two types of glial cells: astrocytes and microglia. A 2017 animal study showed that CBD suppressed the activity and swelling caused by astrocytes;  another 2017 study showed that stimulating cannabinoid receptors in the brain suppressed inflammation caused by microglia in rats.
The Benefits of the “Entourage Effect”
Because full-spectrum CBD contains a variety of phytocannabinoids, it produces an “entourage effect” that engages both the CB1 and CB2 receptors in the brain — as well as other cannabinoid and non-cannabinoid receptors throughout your body — for maximum neuroprotective and overall health benefits.
Although further research is needed, some studies suggest that when CBD is used shortly before or within 12 hours of a brain injury, it may help to prevent or limit the damage that occurs after a TBI during the secondary injury cascade.
Anecdotal Evidence and Research Support CBD Use for TBI and CTE
Although CBD has shown promise for brain injury treatment in the research lab, anecdotal evidence also is strong — especially among some former professional athletes in sports with a high risk of head injuries, such as boxing and football.
Many professional athletes have spoken out about the benefits of CBD for the treatment of TBI and CTE symptoms, saying that it helped to regulate their mood, improve physical function, and reduce or eliminate their use of prescription painkillers and other medications.
Unlike many prescription pain medications, CBD is non-addictive and will not lead to overdose. CBD does not cause side effects and will not result in increased tolerance that requires higher doses to achieve the same effect. CBD also can be used to treat other health conditions that are common in athletes, such as chronic pain, anxiety, and insomnia.
But although anecdotal evidence suggests that CBD may be safe and effective for professional athletes, it also may show promise for the treatment of TBIs caused by youth sports, falls, car accidents and military combat injuries. And, researchers are investigating CBD as a potential treatment for other conditions that affect the brain, including Alzheimer’s disease, Parkinson’s disease, stroke, and HIV-associated dementia.
Researchers are hoping to conduct further studies on CBD and how it can be used to treat TBI and CTE, as well as develop dosing and safety recommendations for CBD use. But in the meantime, many people who have experienced TBI or have been diagnosed with CTE are using CBD to treat the symptoms of their condition — often with life-changing results.
During the past several years, public awareness about brain injuries has increased — thanks in part to several former professional athletes, military veterans, and accident survivors who are speaking out about effects of brain injuries, as well as a variety of brain injury awareness campaigns conducted by athletic and
Cannabis Research and Clinical Trials
Current research is pointing towards CBD serving as a neuroprotectant, possibly helping the brain heal from concussions. Findings also indicate that CBD and/or medical cannabis (marijuana) can be effective for pain management, anxiety, and insomnia, all of which are common symptoms of concussions and Post-concussion Syndrome.
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Please read our Cannabis Health & Safety page. There appears to be a consensus among researchers that cannabidiol is relatively benign. Consumers typically purchase CBD made from hemp, which contains no more than 0.3% tetrahydrocannabinol (THC).
There are numerous contraindications to be aware of for cannabis containing THC (marijuana), meaning that there are circumstances when marijuana could be detrimental. Additionally, people with brain injuries may be more vulnerable to substance abuse, including abuse of marijuana.
Some research focuses specifically on CBD (cannabidiol), which is the nonpsychoactive element of cannabis, and other research focuses on medical cannabis, with various ratios of CBD and THC (tetrahydrocannabinol). CBD is a nonpsychoactive cannabinoid, and THC is the psychoactive cannabinoid.
CBD products are extracted from hemp or marijuana, which are essentially the same cannabis plant but are cultivated differently, hemp plants being grown to contain less than 0.3% THC.
Concussion patients are using CBD oil from hemp, which has virtually no THC, or marijuana products (vape, tincture, etc.) with various ratios of CBD and THC.
We use the term medical cannabis (or medical marijuana) because that is what is being used in research studies. The critical point is that where marijuana is legal, either as medical marijuana or recreational marijuana, the products are regulated and you can purchase marijuana with specific ratios of CBD to THC.
In the United States, the first big study on cannabinoid treatment for concussion is being done by the University of Miami which received a $16 million grant for the research. The study is a five-year, three-stage study that will “assess the effectiveness of a new cannabinoid-based pill to treat concussion injuries. This partnership aims to propel this research and potential treatment forward by using two classes of drugs in a combination that scientists believe will reduce brain inflammation and the immune response.” See also the Miami Herald article.
As reported in UHealth in July 2018, the “findings of a pre-clinical pilot study were recently released, and they show that the combination therapy improved the cognitive functions of animals, compared with those treated with a single vehicle. In addition, there were no adverse effects from either the combination therapy or the individual components.”
The cannabinoid combination therapy is made up of CBD (Cannabidiol, an element of cannabis) and Dexanabinol (HU-211) which is synthetic cannabinoid which is an “anticonvulsant and neuroprotective, and is widely used in scientific research as well as currently being studied for applications such as treating head injury, stroke, or cancer.”
Phase 2 of the study is currently underway. The University of Miami is testing the cannabinoid-based pill on a small pilot study with people, including “a control group and two groups of TBI patients, acute and chronic.” More information can be found on our blog: an interview with Dr. Hoffer.
Dr. Hoffer began a new study in February 2020 to research if “using a pill form of cannabidiol (CBD) and the psychedelic drug psilocybin effectively treats and possibly prevents symptoms of two conditions that commonly occur together: mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD).” “Up to 40% of people impacted by mTBI [or TBI] also suffer from PTSD,” according to a University of Miami press release.
A pre-clinical trial on animals is in progress. Dr. Hoffer expects this phase to last around 9 to 12 months. He hopes to transition to human clinical trials and file the treatment with the FDA in early 2021.
In Canada, a new study led by NEEKA Health Canada will “test if CBD-based therapies can reduce the severity of post-concussion brain disorders in former NHL players.” The National Hockey League Alumni Association and Canopy Growth Corp. (a cannabis and hemp company) are partnering with NEEKA for the clinical research; approximately 100 former players will be enrolled in the randomized, double-blind study. Researchers hope to finish the study by the end of 2020 according to an article in Green Entrepreneur.
In Australia, the medical cannabis company Impression Healthcare began a new clinical trial in mid-2020 to access its new cannabinoid formula IHL-216A on “its ability to protect the brain against the main injury mechanisms which cause cell death and other negative consequences in the days and weeks following head trauma.” Impression will test IHL-216A with in-human and animal trials.
Up to 50 Australian MMA fighters who “receive head knocks and show symptoms of moderate to severe head concussions” will participate in the study. Participants will either receive IHL-216A or a placebo. The effectiveness of the CBD formula will be tested by participants’ baseline neurocognitive tests, which will be repeated throughout the study in both the experiment and placebo groups, and EEG and blood biomarker assessments. Impression Healthcare hopes to have IHL-216A fully approved for market by 2024.
Research indicates medical cannabis improves concussion symptoms
A study published in Brain Injury in October 2019 found that even though cannabis use didn’t affect concussion recovery time, cannabis use was associated with a lower symptom burden in the third and fourth weeks after injury. More information is found in our newsletter post: Study shows cannabis use decreases symptom severity after a concussion.
A December 2018 study in the journal Neurology indicates that medical cannabis (marijuana) helps concussion patients with concussion symptoms, especially pain, mood, sleep, and quality of life. The study also specifies the optimal forms of medical cannabis for the patients in the study, in terms of rations of CBD to THC, and methods of intake, such as a tincture (oral) or a vapor pen (inhaling). Read more in our blog post Study finds medical marijuana improves concussion symptoms.
Highlighting research and clinical trials around the world for use of CBD for concussion and post-concussion syndrome treatment, neuroprotection, and pain, insomnia, & anxiety management.