Huntington’s disease (HD) is an inherited degenerative neurological illness with many similarities to other neurodegenerative diseases, including Alzheimer’s Disease (AD / Dementia) and Multiple Sclerosis (MS). The mechanism of disease involves neuron death from neuro-inflammation, mitochondrial dysfunction, excitotoxicity, and loss of neurotrophic support. The only hope for treatment at this current time is disease stabilization, but there is no evidence from current studies that cannabis will alter its clinical course.
In cell studies, cannabinoids have the ability to module the toxic effects of the Huntingtin protein, leading to optimism that cannabinoid therapies could someday mitigate symptoms or possibly influence the course of this debilitating illness.
CBG and Huntington's Disease
Animal models of HD typically utilize strains of R6 transgenic mice, which show many of the deficits of human disease. The animal studies, with minor cannabinoids such as CBG, show that cannabinoids can potentially adjust some of the disease mechanisms associated with HD. [1] [2] However, a review of the literature for effectiveness of all treatments, conventional or cannabis-based, discovered that there was only weak evidence to support any treatment. [3]
CBD for HD
Three randomized controlled trials (RCTs) focus on the use of cannabinoids in Huntington’s disease. The first [4], a double-blind, placebo-controlled crossover study in 1991, compared oral CBD with placebo in 15 patients for two six-week periods. None of the study results supported CBD’s effectiveness for Huntington’s. The second study, a double-blind, crossover study of 44 patients, compared 1 or 2 mg per day of nabilone with placebo for two five-week periods. [5] The primary outcomes (measures of motor movement, chorea, cognition, and behavior) were all negative. There was an improvement in the secondary outcome—the Neuropsychiatric Index (NPI)—which is important, since neuropsychiatric symptoms in HD are a major dimension of the disease. Combining CBD with a THC preparation might have made a difference. A high-dose THC/CBD study for a longer period might yield positive effects on symptoms.
The most recent trial was a safety study in HD patients completed in 2016, which examined whether nabiximols (Sativex®), a whole-plant cannabis extract spray containing equal amounts of THC and CBD, could improve scores on the Unified Huntington's Disease Rating Scale. The medicine did not improve symptoms on the scale. The study researchers suggested future studies should examine higher doses and other cannabinoid combinations. [6]
Animal Studies
Animal studies of cannabigerol (CBG) have shown promise in experimental rodent models of HD, by providing significant neuroprotection of striatal neurons, and partial normalization of genes that align with HD-type neurodegeneration in the transgenic mouse model employed in the study. [7] HD symptoms, such as sleep, pain, drooling, appetite, mood elevation, and muscle relaxation, do appear to respond to treatment with cannabis.
Recent Research
A study in 2018, showed promising results with respect to the use of both CBD and THC in a balanced ratio to provide neuroprotection and assist with mobility in HD. [11] Another study review from 2019, emphasized the therapeutic potential of CBD in HD. [12] In a 2020 study review of the available evidence on medical marijuana use in HD, researchers concluded that, “larger scale studies are warranted to test the benefits of medical marijuana in HD patients. In the meanwhile, clinicians may consider prescribing medical marijuana as part of their strategy for better symptomatic treatment of patients with HD.”
Cannabinoids Effectiveness
The mechanisms of neuronal death make the actions of cannabinoids an attractive option for treatment. There is less basic science research in HD compared to other more common neurodegenerative diseases, but common pathologic themes emerge. There are HD cell-culture studies that suggest that enhancing CB1 expression with CBD or THC/CBD might be clinically effective in HD. [1] A decrease in CB1 receptor density evolves in parallel with disease severity in postmortem human brain studies, and blockade of CB1 receptors worsens symptoms in HD animal models. Preclinical studies in mice and postmortem human brain sections suggest that CB2 activation plays a pivotal role in attenuating microglial activation and preventing neuro-degeneration. [8] While CB2 receptor density does increase with disease severity, blockade of CB2 receptors also worsens disease in rodent models. CB1 activation could provide symptomatic benefits by decreasing spontaneous motor activity and might potentiate the actions of conventional treatments. [9] It would be advantageous to read our article, The Endocannabinoid System Explained to gain a more indepth understanding of Huntington disease from a full basis deeper than nervous system or cognitive function alone.
Medical disclaimer: prior to making changes to your lifestyle or treatment plan, always consult with your doctor. The information contained in this article is for informational purposes only and does not constitute medical advice. For main drug interactions with cannabis for this disorder, it is recommended to seek the advice of a licenced medical practitioner who has experience recommending medical marijuana or CBD and has read through the new research including the appropriate clinical trials noted here.
Best Dosage for HD
For detailed dosage instructions it is recommended to view the articles found inside the Health Conditions section of our blog related to the specific individual symptoms such as appetite, pain, sleep, and so on. Typically, higher doses of cannabidiol (CBD) combined with average THC doses works well. Patients with neurodegenerative disorders could be more susceptible to unsteadiness, psychiatric side effects, and falls, so caution is advised.
How do you beat Huntington's disease?
People with Huntington's disease can be prescribed antipsychotics, antidepressants, and anti-anxiety medications which can assist with controlling the stumbling and jerking movements called chorea, which can occassionally cause others to believe people with the disease are drunk. For these neurodegenerative symptoms, cannabis has been shown to assist with; see the research on Multiple Sclerosis, and Alzheimer's on our blog.
If disease modification is a goal, the CUPID [10] trial of cannabinoids to counter the symptoms of multiple sclerosis (MS) could be of value: 3.5 mg of THC twice daily orally, with doses increasing by 3.5 mg weekly to a maximum dose of 28 mg twice a day or until THC side effects become intolerable.
Just as with other experimental approaches to neurodegenerative conditions, larger doses of CBD could be added, at least 300 mg per day. The terpene beta-caryophyllene has significant neuroprotective, antioxidant, anti-inflammatory, and immune-modulator action at the CB2 receptor, all aspects that could be helpful in treating neurodegenerative diseases like HD. Beta-caryophyllene can also be found in some cannabis cultivars (so it can be inhaled) and can be swallowed also, if found in enteric-coated form; 25 to 50 mg is thought to be an effective dose. See our Ultimate Guide to Terpenes.
Vaporizing cannabis strains that possess known calming effects are ideal, but would need to be inhaled or taken as a tincture for the most potent effect as terpenes are not believed to survive gastrointestinal ingestion.
Best Strains for Huntington’s Disease
Strains that are high in the terpene myrcene, whether they are CBD or THC dominant, can be of value with respect to pain. Those from the high-THC White family, such as White Widow, or the high-CBD variety ACDC are good choices. Purple varieties are recommended, especially if they contain the terpene linalool, such as Grape Ape or Purple Bubba. For less sedative effects, terpinolene-rich varieties are recommended. For mood elevation, strong limonene THC varieties are effective. For those seeking neuroprotection, a very high-ratio CBD strain, such as Suzy Q, is recommended. Beta-caryophyllene is also a powerful anti-inflammatory and shown to be effective when combined with CBD in providing anti-inflammatory effects. Beta-caryophyllene is found in Cookies and Kryptonite. See our Ultimate Guide to Terpenes.
For more information, see our articles;
Alzheimer’s Disease & Dementia
Parkinson's & Huntington's Disease
For more detailed articles on specific symptoms relating to various health conditions, visit our Blog.
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1. https://pubmed.ncbi.nlm.nih.gov/23659592/
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604192/
3. https://pubmed.ncbi.nlm.nih.gov/22177624/
4. https://pubmed.ncbi.nlm.nih.gov/1839644/
5. https://pubmed.ncbi.nlm.nih.gov/19845035/
6. https://pubmed.ncbi.nlm.nih.gov/27159993/
7. https://pubmed.ncbi.nlm.nih.gov/25252936/
8. https://pubmed.ncbi.nlm.nih.gov/19805493/
9. https://www.sciencedirect.com/book/9780124170414/cannabinoids-in-neurologic-and-mental-disease
10. https://pubmed.ncbi.nlm.nih.gov/25676540/
11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5958190/
12. https://pubmed.ncbi.nlm.nih.gov/31867704/
