CBD For Neurological Disorders: What Does The Research Say?
Anastasiia Myronenko is a Medical Physicist actively practicing in one of the leading cancer centers in Kyiv, Ukraine. She received her master’s degree in Medical Physics at Karazin Kharkiv National University and completed Biological Physics internship at GSI Helmholtz Centre for Heavy Ion Research, Germany. Anastasiia Myronenko specializes in radiation therapy and is a fellow of Ukrainian Association of Medical Physicists.
- What are neurological disorders?
- Types of neurological disorders
- Symptoms of neurological disorders
- How CBD works in the brain
- CBD for specific neurological disorders
- The bottom line
According to recent estimates, over 16.5 million people in Britain currently have some sort of neurological condition. This means that as many as one in six of us understand what it’s like to live with a neurological disorder, and due to our country's ageing population, this figure is only expected to rise into the future. Neurological disorders are medically defined as conditions that affect the brain, as well as the nerves found within the human body and spinal cord. These types of disorders are caused by electrical, structural, or biochemical abnormalities throughout the brain and spinal cord, and they are often expressed in symptoms such as poor coordination, confusion, loss of sensation, seizures, pain, and in extreme cases, altered levels of consciousness.
While neurological disorders vary in severity, a large number of those affected are constantly faced with challenges concerning their mobility, cognitive function, and emotional wellbeing. According to a survey carried out by The Neurological Alliance, 46% of respondents admitted that their condition impacted their quality of life to a great extent, and 42% revealed that it severely impeded their ability to carry out day to day activities. Furthermore, a 2013-14 survey conducted by NHS England on patients of GP practices has shown that people with long-term neurological conditions had the lowest quality of life among other long-term conditions. Therefore, with a clear impetus existing for finding successful treatments, many people seem to be turning to an unlikely remedy - CBD.
So, in this article, we’re going to explore how this herbal compound may be able to relieve symptoms of neurological disorders by investigating what the up-to-date research reveals about its therapeutic potential. In doing so, we hope to equip you with useful information so you’re able to plan your next steps with confidence.
What are neurological disorders?
To understand the causes and characteristics of neurological conditions, you first need to understand a little bit about the nervous system.
The nervous system is a complex and sophisticated network that coordinates the movements and functions of our bodies. The system is what allows us to carry out basic functions like moving, eating and talking, and it lies at the centre of all mental activity including thought, memory, and learning. It’s composed of two parts, the central nervous system which includes the brain and spinal cord, and the peripheral nervous system, which is made up of peripheral and autonomic nerves that run throughout our body. However, in addition to the brain and spinal cord, the nervous system is also present throughout our eyes, ears, skin, muscles and joints. Needless to say, the systems ability to function correctly is critical to our physical and mental health.
Unfortunately, the system can become damaged from a variety of factors including; malnutrition, brain or spinal cord injuries, mutated genes, blood flow disruptions, trauma, infections, and autoimmune disorders. When impairments occur throughout the central or peripheral nervous system, neurological disorders occur. Due to the complexity of our bodies nervous system, there are more than 600 known types of neurological conditions in existence.
Types of neurological disorders
The most common neurological disorders can be classified into these distinct categories, while some belong to multiple groups.
Vascular disorders - Vascular disorders are typically caused by blockages in the vessels that carry blood to and from the heart. They include subarachnoid, subdural, and extradural haemorrhages, strokes, and transient ischemic attacks.
Degenerative diseases - Degenerative diseases are another subset of neurological disorders. They occur when neurons in the peripheral or central nervous system deteriorate Examples of degenerative diseases include Parkinson's disease, multiple sclerosis, dementia, Huntington’s disease, and Alzheimer's disease.
Migraines - Existing as a fairly common neurological disorder, migraines are characterised by severe, throbbing, and recurring pain in the head. While many things are understood to trigger this condition vary, they’re usually induced by emotional, physical, hormonal, environmental or dietary factors.
Epilepsy - Epilepsy is another disorder linked to the central nervous system. The condition can be induced when electrical signals between nerve cells are disrupted, and common symptoms of the disorder include seizures, periods of unusual behaviour, and in extreme cases, a loss of awareness.
Infectious diseases - Neurological infections are caused by viral or bacterial infections. They can accrue when foreign invaders enter the nervous system. Types of neurological infections can include, fungal infections, parasitic infections, brain abscesses, and bacterial infections such as Lyme disease, tuberculosis, and syphilis.
Movement disorders - Movement disorders include neurological conditions that cause increased, abnormal movements that may be voluntary or involuntary in nature. Examples of neurological movement disorders can include ataxia, dystonia, Huntington’s disease, and multiple system atrophy, to name a few.
Neuromuscular disorders - This type of disorder affects the nerves that are responsible for controlling voluntary muscles. Many types of conditions fall under this categorisation, with the most common being multiple sclerosis, muscular dystrophy, motor neurone disease, and myositis.
Functional neurological disorder (FND) - FNS is a medical condition that is characterised by an issue with the functioning of the nervous system and the relaying of signals between the body and brain. This disability restricts the normal functioning of individuals and can cause loss of vision, double vision, tremors, spasms, and in extreme cases, blackouts.
Genetic neurological disorders - Genetic neurological disorders are conditions that run in families. They occur when a mutated gene or group of genes are inherited from parents through genes and chromosomes, and common disorders of this kind include Huntingdon’s disease, Alzheimer’s disease, Parkinson’s disease and Epilepsy.
Symptoms of neurological disorders
While signs and symptoms of a neurological disorder vary depending on the condition, the most common ones include the following:
- Loss or weakness of muscle strength
- Lack of coordination
- Trouble speaking, breathing or swallowing
- Loss of sight, double vision or excessive blinking
- Memory loss or difficulty learning
- Numbness or tingling in a single extremity or on one side of the body
- Headache that changes or occurs suddenly
- Tremors and seizures
- Changes in mood or behaviour
- Loss of feeling or tingling
- Impaired mental ability
- Back pain that spreads to other parts of the body
- Expression or comprehension problems
If you are experiencing two or more of these symptoms at the same time it is recommended to visit a healthcare professional. Also, as the symptoms of a nervous system disorder may look similar to other medical conditions, a consultation with a physician for diagnosis is often necessary.
CBD is a naturally occurring chemical compound that is situated within the cannabis plant. It is one of over a hundred other cannabinoid compounds that are present in the plant, and it’s the second most commonly occurring, topped only by the high-inducing cannabinoid, Tetrahydrocannabinol (THC). Unlike THC, however, CBD is non-intoxicating, and you can safely go about your daily tasks after consuming. Because of the compound's antioxidant, anti-inflammatory, and neuroprotective properties, CBD boasts a broad spectrum of potential therapeutic benefits. It also modulates higher numbers of the brain’s biological targets (such as receptors, channels) involved in the development and maintenance of neurodegenerative diseases.
How CBD works in the brain
Although the exact way CBD interacts with our brain remains unclear, the compound is understood to elicit physical and physiological effects via its interaction with our bodies endocannabinoid system (ECS). This complex regulatory system is present throughout every organ and every key system in our bodies, including the immune and central nervous system.
By binding to and activating CB1 and CB2 endocannabinoid receptors that exist within the system, CBD is understood due to its interaction with our bodies endocannabinoid system (ECS). Our ECS is a complex signalling system that is present throughout our whole body, including our central nervous system. The network is composed of endocannabinoids, enzymes, and CB1 and CB2 receptors. CB1 receptors are prominently located throughout our central nervous system, intestines and connective tissues, and our CB2 receptors exist within our spleen, tonsils, thymus, immune cells, and some areas of the brain. Data suggests that by modulating how these receptors respond to stimulation, CBD is able to affect the brain and body in numerous ways. In doing so, this is how the compound is understood to showcase it’s potential neuroprotective and therapeutic values.
CBD for specific neurological disorders
Since its first reported use in 2,600 BC, the cannabis plant has been lauded across cultures for it’s potential physical, psychological, and neurological benefits. So, it’s no surprise that the cannabis derivative, CBD, may also hold some medical value. Unfortunately, in modern Western medicine, cannabis-derived medicines have been overlooked for much of the twenty-first century due to longstanding bans on their use and circulation. But in recent years, as research into the compound’s potential grows, a number of studies have suggested that cannabinoid-based therapies could be helpful for addressing the symptoms associated with many neurological conditions.
So, next, we discuss how CBD-based therapies have been shown to support neural health when used to address specific neurological disorders.
Multiple sclerosis is a disease that attacks the brain, spinal cord, and nerves. Among other treatments, cannabis has long been used as a way to help people deal with the symptoms associated with the condition. In fact, according to a survey conducted by the MSSociety in 2014, one in five people surveyed admitted to using medical cannabis to help relieve MS symptoms including muscle spasms or stiffness and pain, with this figure rising to 66% in the US. And this use is substantiated by evidence. According to a review carried out by the Americal Academy of Neurology (ANN) in 2017, cannabis-based products were found to lower instances of neuropathic pain, lower spasticity, and improve sleep for those experiencing MS.
Fortunately, as an increasing number of MS sufferers are looking to find non-psychoactive alternatives, data also suggests that CBD could also be used to relieve certain symptoms of multiple sclerosis. As this 2018 study and others detail, by decreasing levels of inflammation, cannabidiol has been shown to reduce muscle spasticity and levels of pain that are associated with the condition. More specifically, by reducing chronic peripheral inflammation that can often result in overactivity of the vagus nerve, the compound has also been found to reduce levels of fatigue that are also associated with the neurological condition. Whatsmore, although no specific research into cannabis-derived products and mobility has been conducted, due to indirect evidence into the compound’s ability to mitigate symptoms that contribute to fatigue, it’s likely that CBD products would also result in improvements in the mobility of people with MS.
Parkinson's is a chronic progressive neurological disease that mainly affects middle-aged and older people. The disease is associated with decreased dopamine production and symptoms, such as rigidity of the muscles, tremor and slow movement. Luckily, cannabidiol has been shown to inhibit brain-protective, antioxidant and anti-inflammatory properties which may be useful for managing Parkinson's disease. Also, as Cochrane Library points out, human trials conducted on those with Parkinson’s reveal that CBD may be able to decrease anxiety and psychosis associated with the condition, while also improving other motor and non-motor symptoms. This is understood to be due to the compounds purported antipsychotic and anxiolytic effects. However, more research into CBD’s effect on Parkinson’s symptoms needs to be conducted before the compound can be used as a reliable way to help those living with the disease.
In addition to showing potential as a therapy for Parkinson’s, CBD also may be able to remedy the symptoms of another neurodegenerative disorder, Alzheimer’s disease. As this 2019 research article into the medical uses of cannabis reveals, cannabinoids like CBD may be able to reduce the impact of some Alzheimer’s symptoms, because of the compounds neuroprotective anti-inflammatory properties. Since Alzheimer’s symptoms are enhanced when the brain’s immune cells can not clear disorientating blockages, by lowering inflammation in the affected zones, the cannabidiol may be able to control the impact of the condition. Whatsmore, as data from this study shows, by acting as an antioxidant, CBD may also be able to lower levels of oxidative stress in the brain, and this is significant when it comes to Alzheimer’s because it’s memory loss symptoms are worsened from oxidative stress.
In addition to controlling the impact of Alzheimer’s after it emerges, there is also promise that CBD and other cannabinoids may be able to lower the chances of it occurring in the first place. As this study conducted on mice reveals, CBD has been shown to reverse the cognitive deficits of mice who were genetically predisposed to Alzheimer’s because of the extracts neuroprotective anti-oxidative, and anti-inflammatory properties. The study also pointed out that CBD may be particularly useful at improving facial recognition and decreasing social withdrawal that are both associated with the condition. So, although more research into the matter needs to take place before conclusive results can be drawn, these preliminary studies are able to open up discussions around CBD’s use as a preventative treatment for Alzheimer’s disease.
Otherwise known as Huntington's chorea, Huntington’s disease is an inherited disease that leads to the death of brain cells. The earliest symptoms include slight problems with mood or mental functions, that develop into a lack of coordination and an unsteady walk. Unfortunately, there are only a few on the role of CBD in the treatment of Huntington's disease and movement disorders. However, due to cannabidiols anti-inflammatory properties, it’s likely that the compound may be able to mitigate some symptoms of Huntington’s disease in the same way it may be able to do with Parkinson’s and Alzheimer’s. Whatsmore, as this research article from Front Pharmacol suggests, due to cannabidiols potential neuroprotective effects, it’s likely that the agent may be also successful in preventing or at least postponing, the onset of the neurological disorder.
As we outlined earlier in this article, epilepsy is a neurological disorder that affects the brain and often causes frequent seizures. Fortunately, as this 2019 study on the use of Epidiolex (an oral solution of cannabidiol), has shown, CBD based therapies hold potential in decreasing seizure frequency for those living with epilepsy. The research article points out that the compound's anti-epileptic potential may be due to its neuroprotective activity, which stems from it’s anti-inflammatory and antioxidant properties. It also claims that the treatment of CBD could be useful for those who are resistant to all conventional anti-epileptic drugs.
Also, in addition to CBD showing potential in reducing seizures associated with epilepsy, there is also data that suggests cannabidiol-infused medicine may be able to lower seizure activity connected with Dravet Syndrome, a rare form of childhood epilepsy. As this 2020 study outlines, in a study of 120 children living with Dravet Syndrome, those who were administered with cannabidiol witnessed a much greater reduction in convulsive-seizure frequency, compared to the control group. So, as these studies suggest, for those experiencing seizure symptoms as a result of a neurological disorder, CBD based therapies may be a viable alternative or supplement to other conventional anti-epileptic drugs, especially for those who are resistant to more established therapies.
Chronic pain is a common symptom of many neurological disorders, affecting up to 40% of patients with primary neurological diseases. Often caused by traumatic injury to the central nervous system, neuropathic pain is often treated with more established pharmaceutical painkillers. But with research into CBD’s analgesic potential growing, an increasing number of people suffering from neuropathic pain are turning to cannabidiol-based therapies because of the compound's relatively mild side effects.
And there’s data to back this up. As this 2012 study into cannabinoids and neuropathic pain points out, non-psychoactive cannabinoids like CBD hold potential in lowering cases of pain associated with neurological disorders. Due to the analgesic potency of CBD, and it’s ability to suppress chronic inflammatory and neuropathic pain, it’s possible that CBD could be used as part of a wider effort to address the pain that emanates from nerve damage. Due to the analgesic effects and anti-inflammatory qualities of cannabidiol, when mice were intravenously administered with the compound, inflammatory and neuropathic pain levels were shown to decrease. Due to CBD’s potential for addressing cases of neuropathic pain, the cannabis-based medicine Sativex has been approved in multiple countries, besides the UK, for the treatment of neuropathic pain and multiple sclerosis-related muscle spasms. Numerous clinical trials have shown the efficacy and safety of Sativex in central and peripheral neuropathic pain. However, cannabis-derived remedies are not commonly applied for severe pain.
Migraines are much more than intense headaches. They include a number of neurological symptoms, such as a throbbing recurring pain on one side of the head and muscle stiffness. Fortunately, a 2019 review suggested that cannabinoids may be able to modulate the activity and functions of signalling pathways, helping to alleviate the pain associated with migraines. Initial clinical findings show that modulation of the endocannabinoid system with cannabinoids may be helpful for migraine. Whatsmore, a 2007 study also suggested that people with migraine might have low anandamide levels in the cerebrospinal fluid, which signifies that they may have a compromised ECS. Therefore, modulation of the ECS with cannabinoids could become a promising treatment for migraines. Nevertheless, further studies are required to take place before we fully understand this process.
Anxiety and sleep loss
Anxiety and insomnia are symptoms that feature heavily with a range of neurological conditions, so addressing these consequences is an effective way to improve the quality of life of those living with such disorders. There is evidence out there that suggests CBD may be able to lower levels of anxiety, which by default, may be able to alleviate cases of insomnia too. The exact way CBD may be able to affect sleep and anxiety isn't entirely clear, though this piece of research suggests the compound may be able to benefit mental health by altering serotonin signals.
The results of this study are corroborated by a 2019 large case series that evaluates the clinical application of cannabidiol for anxiety and sleep disorders. The study, which included 103 adult patients, found that anxiety scores diminished within the first month in up to 80% of the patients and remained lowered during the study. In addition to this, sleep quality improved within the first month in 66.7% of the patients, although this did reduce over time. So, as the results of these studies indicate, cannabidiol may indeed be able to benefit patients with sleep and anxiety-related disorders, but further clinical studies are needed before we know for sure.
What cannabis treatments are available for neurological disorders?
As cannabis is regulated in different ways all over the world, each country has its own rules regarding cannabis-based medications. In the UK, cannabis for medical purposes was legalised on November the 1st 2018. CBD-based medications can now be prescribed by a specialist medical practitioner, included in the register of specialist medical practitioners, or a tertiary paediatric specialist for children and young people. The patients can get prescriptions for licensed medical cannabis covered by the NHS or obtain private prescriptions with no NHC coverage.
A shortlist of approved cannabis-based medications and strict requirements to potential patients challenge the way to get a prescription for medical cannabis. The NHS coverage remains difficult and rare in the United Kingdom. Private clinics can provide an easier option to access medical cannabis, covering a broader range of conditions, such as pain and neurological conditions. Unfortunately, this is typically more expensive, with private appointments costing around £200-250 and prescriptions totalling around £600-800 per month.
Currently, in the UK, only three cannabis-based drugs are legal and available for prescription, and only two of these are designed for neurological disorders. They include the following:
Produced by GW Pharmaceuticals, Epidolex is a plant-derived cannabidiol-based medicine that is predominantly used to treat seizures associated with Lennox-Gastaut syndrome and Dravet syndrome in children. NICE, the UK’s drugs advisory body, followed the recommendations of the European Commission, who suggested that the combination of Epidiolex and anti-epileptic generic drug clobazam (brand names Onfi and Sympazan) for the patients, aged two and older. As of 2019, out of the 3,000 people who had Dravet syndrome and the 5,000 people who suffered from Lennox Gastaut syndrome, 2,000 people could qualify for Epidiolex in England.
With regards to its effectiveness, data from numerous trials and studies have suggested that Epidiolex could reduce seizure frequency by up to half, as well as counteracting a range of other neuropathic symptoms. For example, this study into the Epidiolex’s potential for those experiencing Tuberous Sclerosis revealed that those who were treated with the medicine experienced a greater reduction in seizures compared to those who were taking the placebo. Also, as this clinical trial into the efficacy of cannabidiol for children and young adults with Dravet syndrome reveals, out of 199 participants, 50% experienced a marked decrease in seizure symptoms. So, the use of Epidiolex in remedying symptoms associated with neurological conditions has received some scientific backing. But with the medicine understood to induce a range of potential side effects including sleepiness, fever, appetite loss, diarrhoea, and vomiting, this should also be taken into consideration before the remedy is used to try and combat existing neurological symptoms.
Sativex is a mouth spray containing two chemical extracts delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD). In the UK, the medication is approved for the treatment of spasticity in multiple sclerosis, though it is not allowed to treat pain in the same condition. Sativex is a Class B controlled drug under the Misuse of Drugs Act 1971 and is placed in less-restrictive Schedule 4 according to the Misuse of Drug Regulations 2001. Sativex can be prescribed by a specialist doctor experienced in the treatment of multiple sclerosis, such as consultant neurologists, consultant rehabilitation specialists, and consultant pain specialists. The drug can be prescribed legally in the UK with no restrictions on storage, supply and destruction.
The use of Sativex, a cannabinoid-based mucosal spray, has been proven to be a safe and effective way to reduce a range of neurological symptoms. As this review of clinical studies shows, Sativex is shown to be particularly effective in reducing symptoms associated with multiple sclerosis. Data produced by the study revealed that the treatment dramatically reduced muscle spasticity in patients with moderate to severe multiple sclerosis resistant to other medications. In addition to this, another study found that Sativex provided relief in resistant multiple sclerosis spasticities in 75% of 276 people, proving the drug has the potential to be an effective and well-tolerated treatment.
If patients respond positively during the first four weeks of treatment, they may continue with the drug. However, despite the clear benefits of the treatment, the use of Sativex can feature some side effects. These side effects include dizziness, drowsiness, diarrhoea, fatigue, constipation, concentration or memory loss, dry mouth, and altered sense of taste, and they typically occur during the first days of the treatment.
The bottom line
As ongoing research and developments into potential health benefits of CBD continue to take place, it appears that public sentiments are continuing to sway in favour of the therapeutic potential of cannabidiol. This, alongside the growth in cannabis-derived products, is leading cannabinoid growth to rise exponentially, with the global cannabidiol market expected to exceed £64bn by 2026, according to this report by Global Market Insights.
However, with there still being so many unknowns about CBD relationship with neurological disorders, much more research into the compound's neurological potential needs to take place. Also, as the global CBD market continues to grow, it's clear that the industry needs to overcome complex regulations and quality challenges if the use of cannabinoids for neurological conditions can be supported in the long run.