Can Cannabis Help Huntington's Disease Patients?
Feb 16, 2020
While research is still in its early phases, studies have found evidence supporting the use of cannabis for Huntington’s Disease. These studies suggest that cannabis may be able to help as a neuroprotectant, as well as reduce symptoms like irritability, uninhibited behavior, uncontrolled movements, and hypersalivation. It may also improve a patient’s cognitive measures, movement control, and the ability to walk.
While more research is needed, what research we do have gives hope that cannabis may help those suffering from Huntington’s Disease.
How Cannabis Works on Huntington’s Disease
The endocannabinoid system (ECS) exists in all vertebrates and helps regulate crucial functions such as sleep, pain, and appetite. The human body produces its own cannabinoids, which modulate and activate its various functions, but as its name suggests, the endocannabinoid system can also be modulated and activated by cannabinoids found in the cannabis plant. Because the entire system was only discovered in the past 30 years, scientists still have much to learn about the myriad ways cannabis affects the human body.
When it comes to Huntington’s Disease, scientists have discovered that the ECS plays an important role in the progression of the disease. In fact, some have even suggested that imbalance or deficiency of the endocannabinoid system is a cause of Huntington’s Disease.
For one thing, we see differences in important areas of the brain for patients with Huntington’s Disease compared to the general population. One important area is the basal ganglia, a part of the brain involved in movement. This part of the brain is usually rich with endocannabinoids, as well as the receptors they activate and the enzymes that break them down. But in post-mortem studies on patients with Huntington’s Disease, most patients have had a massive loss of CB1 receptors (one of the primary receptors for the endocannabinoid system) in the basal ganglia.
Other studies, on both animals and humans, show loss of this receptor in other areas of the brain related to Huntington’s Disease, as well. Some even suggest that a decrease in this receptor’s mRNA (a molecule that conveys genetic information) is the first sign of Huntington’s disease and a hallmark of its early stages. Animal studies have even tied loss of CB1 receptors to worsening motor function and the physiological development of Huntington’s Disease.
In late states of the disease, we also see increased levels of CB2 — another important receptor for the endocannabinoid system.
In addition, animal studies show a significant changes in the amount of key endocannabinoids like anandamide and 2-AG in the brains of Huntington’s Disease patients; with decreased levels in multiple parts of the brain as the disease progresses, and then an increase in anandamide in the cortex during late stages of the disease.
Generally, these insights suggest that there are region and stage specific impairments of the endocannabinoid system in Huntington’s Disease. Researchers suggest that both drugs that activate CB1 or CB2, or ones that inhibit them could potentially be helpful for treating this disease, but more research is needed to understand how to do this effectively.
Medical Studies on Huntington’s Disease and Cannabis
While the data on how the endocannabinoid system impacts Huntington’s Disease gives us some hope that cannabis might be able to help with this degenerative condition, we need to look at the direct research on using cannabinoids for Huntington’s Disease to learn when and how it could be effective. Unfortunately, the research is still in early phases, and is conflicted at points, but much of it suggests that cannabis could help.
To begin with, animal studies suggest that treatment with THC, the most common cannabinoid in the cannabis plant, can help with Huntington’s Disease as a neuroprotectant, potentially slowing the progression of the disease.
Some case studies also suggest that cannabis could help with the condition. In one case study from 2006, a female patient with Huntington’s Disease had significant improvements using cannabis, and later nabilone (a synthetic version of THC). Her caretakers found that using these cannabinoids improved her mood, reducing irritability, uninhibited behavior and angry outbursts. She became calmer and more patient and also saw improvement in her controlled movements with less chorea (involuntary dance-like movements common to Huntington’s Disease).
These positive results from case studies and animal research has led to studies of cannabis for Huntington’s Disease, some of which have brought back positive results.
A 2009 study on cannabis and Huntington’s Disease showed that patients treated with nabilone were found to have moderate improvements in motor skills, chorea, and cognition. Then, a 2012 study looked specifically at treating chorea with cannabis and found it caused moderate improvements. Unfortunately, in both cases the researchers used low doses so other researchers have pointed out these studies were underpowered to show more than these moderate improvements.
In a 2018 study, researchers reviewed previous literature on the topic and found that cannabis use could lead to improvement of motor symptoms, weight gain (a desired outcome in this case), behavior and mood. They found those using cannabis were less irritable, less apathetic, and experienced less hypersalivation.
Unfortunately, not all research on cannabis and Huntington’s Disease has come back with positive results. In fact, several clinical trials suggest that cannabis has no effect on the condition. For example, in a 2016 double‐blind, randomized, placebo‐controlled clinical trial using Sativex (a cannabis extract containing THC and CBD), no significant differences were found between those using Sativex and those using a placebo on measures of motor, cognitive, behavioral, and functional skills. In addition, no changes were noticed in important biomarkers for the condition. Still the authors of this study recommended it be replicated with higher doses of cannabis.
In other cases, research showed potential for cannabis to be detrimental to the condition. Animal studies have shown potential for THC to exacerbate some aspects of the condition, and in an uncontrolled clinical study, a single dose of nabilone left one patient with Huntington’s Disease with markedly increased chorea.
Still, the majority of the research leads scientists to feel hopeful that cannabis could be a helpful treatment — and should continue to be researched for its potential to treat Huntington’s Disease.
CBD and Huntington’s Disease
While most research on cannabis focuses on high THC varieties of the plant, or THC-based medicines, some have also looked at whether another component of the plant, CBD, might be helpful when used by itself. And there is reason to believe it may help with Huntington’s Disease.
In 2017, the World Health Organization reported that CBD may play a role in treating Huntington’s Disease and a 2018 review of the literature found that CBD has potential for helping with movement disorders including Huntington’s Disease.
In animal studies, CBD was even able to reverse neuronal loss from toxicity in Huntington’s Disease. However, in some controlled clinical trials, patients treated with CBD did not show improvements. Still some researchers suggest these experiments need to be done with higher dosages.
In studies on cannabis use in Huntington’s Disease, patients experienced side effects such as nausea, increased weakness, behavioral or mood changes, suicidal ideation, hallucinations, dizziness, fatigue, and feelings of intoxication. These studies were primarily using lower doses of cannabis. But those taking higher doses that include THC may also experience anxiety and in rare cases, psychosis.
The Cannigma content is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Always consult with an experienced medical professional with a background in cannabis before beginning treatment.
About Huntington's Disease
Huntington’s disease is a progressive brain disorder named after Dr. George Huntington, the doctor who first classified it in the late 19th century. Huntington’s is an inherited disease, caused by a faulty gene that makes the nerve cells in parts of the brain break down over time. This leads to the development of difficulties in walking, speaking, and swallowing, involuntary jerky movements, cognitive decline, and personality changes.
Most people with Huntington’s disease begin to show symptoms in their 30s and 40s, but it can also develop much later in life, or at a much younger age. When the disease develops before the age of 20, it’s termed Juvenile Huntington’s disease. Juvenile Huntington’s disease has additional symptoms, and it tends to progress more quickly than the adult version.
Huntington’s disease is quite rare. It’s thought that it originated in northern Europe, and it’s far more common in the UK and among people of northern European descent. In western Europe and the US, approximately 5 to 10 out of every 100,000 people have Huntington’s, compared with under 1 out of every 100,000 people in Asia. However, there are some geographic pockets where Huntington’s disease is more common.
There’s no cure for Huntington’s disease and no way to slow down or reverse the gradual decline, although treatment can help people to manage their symptoms. Eventually, physical weakness leads to pneumonia, heart failure, or other fatal secondary complications. Most people with Huntington’s live 15 to 20 years after diagnosis, but that’s reduced to 10 to 15 years for people with juvenile Huntington’s disease.
It is a devastating diagnosis to receive, both for the sufferer and for the family. Unfortunately the disease entails a progressive and gradual worsening of every aspect of life both physically and mentally. It’s not easy on families and loved ones to say the least. That is why it is both important to seek out professional help in managing the symptoms, and in parallel for the medical community to strive towards more effective treatments and eventually, a cure.
The early symptoms of Huntington’s disease are quite mild and can be hard to detect, but they become more serious and evident as the disease progresses. Different people can have distinct symptoms. Often, each person will experience more symptoms from a particular category. For example, in one person Huntington’s could primarily affect their speech, while in another person, their walking is impaired faster than their speech.
The most common and earliest symptom of Huntington’s is often depression. This isn’t in reaction to learning about the diagnosis of Huntington’s, but due to changes to the brain function because of damage to brain cells. Other early signs of Huntington’s include:
- Small, jerky, involuntary movements
- Poor coordination
- Difficulty learning new information
- Trouble making decisions
As the disease progresses, other symptoms appear. These include:
- Involuntary jerking or writhing movements, called chorea
- Abnormally tight or contracted muscles, called dystonia
- Slow or abnormal eye movements
- Difficulty speaking or swallowing
- Impaired motor movements like walking, balance, and writing
- Difficulty focusing and getting organized
- Impulsive, risky behavior
- A lack of self-awareness
- Difficulty processing thoughts, learning new information, and finding words
People with Huntington’s disease are also likely to develop psychiatric disorders like anxiety, obsessive-compulsive disorder, mania, bipolar disorder. They may also have hallucinations and delusions. They may display symptoms of aggression, agitation, or anger, and frequently lack energy, withdraw socially, and experience difficulty sleeping. They might also undergo personality changes.
Juvenile Huntington’s disease brings added symptoms. These include:
- Slow, clumsy movements
- Frequent falls
- Tight, rigid muscles that affect their walk
- Slurred speech and drooling
- Sudden and significant decline in academic performance
Around 30-50% of children with juvenile Huntington’s disease also experience seizures.
Once the doctor suspects Huntington’s disease, it’s easy to confirm. The disease is caused by defects in a specific gene which was identified in 1993, so doctors carry out a blood test to spot the defective gene for Huntington protein. This can confirm Huntington’s disease in people who are already showing symptoms, and also in those who have no symptoms yet, but eventually will. If one of your parents has Huntington’s disease or has tested positive for the defective gene, it’s best to get genetic counselling as well as talking with your physician.
Genetic testing can also be important in terms of planning for the future, because testing positive for the gene means you will definitely eventually develop the disease. Family planning is also important potentially avoid passing it on if you want to have children.
The symptoms of Huntington’s disease are very similar to those caused by a number of other far more common disorders, including Alzheimer’s disease, a tumor, or neurological conditions. That’s why it’s important to go to a doctor who takes a full medical history, listens carefully to reported symptoms, and observes your movements, speech, and behavior. Other blood tests and medical imaging scans might be carried out before the doctor concludes that it could be Huntington’s disease.
Huntington’s disease is caused by a known defect in a single specific gene. It’s called an autosomal dominant disorder, which means that someone who only inherits one copy of the defective gene will develop Huntington’s. It affects both men and women equally. If someone has a parent with Huntington’s disease or with the defective gene, there’s a 50% chance that each child will inherit the defective gene.
There is no cure for Huntington’s disease, and no way to delay or stop the changes that it causes within the brain. Treatment that combines oral medications with various types of therapy can help manage the impact of the symptoms of Huntington’s disease, especially in relieving the psychiatric elements like depression, and controlling movement disorders like chorea.
There are 2 main types of medication that are prescribed to treat chorea:
- Atypical (next-generation) antipsychotics, such as olanzapine, haloperidol (Haldol) and chlorpromazine have the side effect of suppressing involuntary movements. However, they can worsen dystonia and muscle rigidity.
- Tetrabenazine (Xenazine), which is specifically approved for treating Huntington’s disease, but can also worsen or trigger depression and other psychiatric conditions.
Other medications that are sometimes prescribed to control movement disorders in patients with Huntington’s include amantadine, levetiracetam, and clonazepam (Klonopin).
Doctors will assess the person’s emotional and mental state before choosing which drugs to prescribe for psychiatric disorders, but some common medications are:
- Atypical antipsychotics like quetiapine, risperidone, and olanzapine, for severe anger and threatening behavior.
- Antidepressants like citalopram, escitalopram, fluoxetine, and sertraline, for depression and obsessive-compulsive disorder.
- Mood-stabilizing drugs like valproate, carbamazepine, and lamotrigine, for bipolar disorder.
It’s recommended to use various types of therapy along with medication to help ease the symptoms of Huntington’s disease.
Psychotherapy, also called talk therapy, can help with behavioral problems, self-awareness, and to develop coping strategies.
Speech therapy helps strengthen the muscles used for talking, eating, and swallowing, teach people with Huntington’s disease more ways to speak more clearly and assist in finding communication devices when the person can no longer communicate through speech.
Physical therapy guides people with Huntington’s disease to carry out gentle exercises for balance, flexibility, strength, and coordination so that they are at less risk of falling and can remain mobile for longer. Physical therapists also teach people with Huntington’s how to improve their posture to reduce movement problems.
Occupational therapists help patients with Huntington’s disease, as well as their families and caregivers, to find the right assistive devices, like equipment to help with bathing and dressing, walkers and wheelchairs, and adapted eating and drinking utensils.