Decoding Cannabis: How medical cannabis (THC and CBD) helps manage neurological conditions

Medical cannabis for neurological conditions has come a long, long way over the past few decades.

Up until the early 1900s, it wasn’t uncommon for cannabis-based tinctures to be prescribed for not only pain but also neurological issues, including seizures and muscle spasms. Then came a long period of silence. A century of the “war on drugs,” full of legislative overreach, somewhat unnecessary political caution, and pure scientific neglect.

Thankfully, that is all starting to change. 

Medical cannabis has been a fully legal treatment option here in the UK since late 2018, but it is only in the past 18 months or so that we’ve seen patient numbers begin to grow at pace. Many of those patients are looking for an alternative option to help ease the impact of neurological conditions when conventional routes have come up short. 

Here, in 2025, most of the UK population has seen the news reports on how therapeutically beneficial cannabis-based treatment options can be for people living with epilepsy and multiple sclerosis, but that’s only one small part of the cannabis for neurological issues picture. 

UK patients with Parkinson’s, Tourette’s, peripheral neuropathy, neuropathic pain, and other neurological conditions are also turning to cannabinoid treatment options (THC and CBD). They’re not here chasing trends. They’re looking for relief from tremors, spasticity, anxiety, nerve pain, insomnia, and many of the secondary symptoms.

In this week's Decoding Cannabis continuation, we aim the microscope at a 2023 major clinical review that brought together the evidence on how cannabis is being added to neurological treatment plans. 

Titled “Therapeutic use of medical Cannabis in neurological diseases: a clinical update” the authors pulled data from controlled trials, real-world surveys, and preclinical studies, examining not just what patients are prescribed, but why and how the compounds interact with the brain and nervous system.

This article walks through that review (with some light supplementation from other pieces of research), condition by condition. We’ll see what the authors of the review found, where the gaps are, and what all of it might mean for people living with complex, often incurable neurological conditions.

How the endocannabinoid system affects the nervous system

This review doesn’t explain the biology of medical cannabis treatment extensively, so we won't either. For a brief but an explanation of the endocannabinoid system and how medical cannabis interacts with it, head to “What is the endocannabinoid system?”

For the sake of this blog, we’ll summarise: the ECS is the largest neurological signalling system in the human body, with two main receptor types: CB1 and CB2.

The ECS has a controlling hand over an extremely wide range of functions, from pain signalling and muscle tone, to sleep, mood, appetite, inflammation, and memory.

What roles do the CB1 and CB2 receptors play in brain activity?

CB1 receptors are found mostly in the brain and spinal cord. They’re involved in regulating movement, memory, mood, and how we process pain and other sensory input. When activated, they can dampen seizure activity or calm overactive pathways.

CB2 receptors are found more in immune cells, or in the membranes of those cells, to be precise. They help regulate inflammation and respond to injury or disease. While they are mostly outside the brain, they can appear in the nervous system during stress or degeneration, such as in MS or ALS.

Cannabis compounds (cannabinoids) can mimic or amplify the natural endocannabinoids we produce to operate within these systems, and this explains why cannabinoids can have such broad neurological effects. They often work not by targeting one symptom or pathway, but by helping to steady the system itself. 

How do THC and CBD differ in their neurological effects?

THC has been shown to interact very strongly with CB1 receptors, which is why it can affect mood, memory, and even perception, but it also has practical effects. 

It may help with chronic pain, muscle tightness, nausea, mental health concerns, and appetite issues. These aren’t always the first symptoms to be targeted for treatment in neurological conditions, but they are often the ones that make day-to-day life harder. That’s where THC can play a role.

CBD, on the other hand, doesn’t bind as strongly to CB1 or CB2. Instead, it works more quietly across other systems in the body. It’s been linked to calming inflammation, easing anxiety, and helping with seizures, and does so without producing a ‘high’.

Because they act differently, but within the same broader system, THC and CBD offer different tools for patients and clinicians. When conventional treatments fall short, this kind of flexibility can make a meaningful difference.

This difference between the two is one reason cannabis has become so interesting to researchers and patients alike. THC and CBD affect the same system in very different ways. That separation gives us options when thinking about how to treat complex, overlapping symptoms.

What does the evidence say about medical cannabis for neurological conditions?

The review in question involved a huge number of available studies to give us a clearer picture of how THC and CBD are being implemented to aid in neurological care. While the strength of evidence varies from condition to condition, a few consistent patterns have started to emerge.

Keep in mind that with medical cannabis legality spreading globally, so too is wider access for researchers. We're only just beginning to see what’s possible.

Epilepsy and seizure disorders

Epilepsy and seizure disorders is one of the clearest, most evidence-backed areas of medical cannabis research (especially when it comes to helping treat neurological issues). 

CBD has been shown in multiple large-scale trials to heavily reduce seizure frequency in certain types of conventional treatment-resistant epilepsy, particularly in Dravet’s and Lennox-Gastaut syndromes. 

The review highlights this as a clear success story, with benefits sometimes extending beyond seizures to improved sleep and quality of life. THC isn’t used as often due to psychoactivity, but some formulations do include small amounts to help with some of the secondary symptoms.

In rare and extreme cases where licensed options aren’t available, some experts support the careful use of purified or synthetic CBD, especially where standard treatments have failed.

Multiple sclerosis (MS)

The evidence in the review for MS and medical cannabis is moderate, but very promising. 

The review points to several trials showing that THC:CBD blends (most notably Sativex) can help reduce muscle spasticity and stiffness in MS patients who haven’t responded well to standard therapies. THC also seems to support pain relief and sleep for MS patients. CBD alone hasn’t shown strong results in MS according to this paper, but may still contribute indirectly through anti-inflammatory effects.

Self-reported data adds weight to the clinical findings. In a Canadian survey noted in this paper, many MS patients reported using THC-containing cannabis to manage spasticity, pain, and sleep problems, with most describing positive effects despite mild side effects like drowsiness or reduced concentration.

Parkinson’s disease

Formal research on cannabis and Parkinson’s remains sparse, but patient-reported data suggests real potential. CBD may help with anxiety and sleep disturbance, while some patients find that THC reduces tremors and/or improves motor control. 

Surveys suggest up to 37% of people with Parkinson’s have tried cannabinoids, mostly to ease tremor, stiffness, sleep issues, anxiety, or pain. Inhaled THC seems to be the preferred format, with some patients reporting reduced need for conventional medications. 

So far, clinical trials have shown mixed results for Parkinson’s treatment with cannabis. Meta-analyses haven’t found consistent improvements in motor symptoms, partly because studies vary widely in design and cannabinoid content. A small trial of synthetic THC (Nabilone) did show benefit for anxiety and sleep.

Animal studies suggest CBD might protect brain cells through anti-inflammatory and antioxidant effects, but this hasn’t yet been confirmed in humans. 

Tourette’s syndrome (and other Tic disorders)

The evidence in the review here is mixed. 

While some patients report benefit, and a recent European survey ranked THC among the top ten treatments for Toutette’s tics, clinical trials tell a more cautious story.

A meta-analysis based on two small RCTs found no significant reduction in tics with THC. Sativex (a THC/CBD spray) appears safe, but most data come from open-label or retrospective studies, making conclusions difficult. Experimental approaches like MAGL inhibition (which boost our own levels of natural endocannabinoids) also failed to show lasting benefit in larger trials.

That said, Releaf patient Harry has seen a dramatic improvement in daily function, sleep, focus, and tic severity since starting medical cannabis for Tourette’s syndrome. His story serves as a stark reminder that individual outcomes do sometimes exceed what the currently available data predict, which only highlights the need for further clinical research, especially human trials.

Alzheimer’s disease and dementia

Evidence here is still in the early stages, but quite intriguing. 

The research that the review honed in on showed that cannabinoid therapy may help reduce neuroinflammation and oxidative stress, which are two processes thought to contribute to cognitive decline. In early lab and animal research, cannabinoids have been shown to reduce the build-up of harmful proteins in the brain and ease the kind of inflammation and stress thought to play a role in Alzheimer’s disease.

Clinical data in humans is, unfortunately, still way too sparse to make any concrete claims about efficacy. A few small studies in the review have looked at THC for agitation and sleep problems in dementia, with mixed but generally positive findings. 

No trials to date have shown that cannabinoids can slow the progression of dementia itself, but their role in symptom management is a clear target for researchers to further look into.

Neuropathic pain

A major Cochrane review found that only around 1 in 20 patients experienced a 50% reduction in pain, while 1 in 25 stopped treatment because of side effects. The evidence itself is somewhat lacking, but even so, researchers cautiously concluded that the potential benefits may outweigh the risks for some patients.

In practice, prescribing patterns reflect this cautious optimism. 

In Germany, cannabis-based medicines are often prescribed for nerve-related pain, especially when other treatments haven’t helped. Dronabinol was the most common option, followed by dried medical cannabis flower. The review states that many of the patients surveyed reported better sleep, less pain, and an improved quality of life.

A study that came out of the University of Sydney in 2017 (that was not included in the review) found that “THC and CBD reduced neuropathic pain. CBD had no adverse side effects. The 1:1 combination of THC and CBD synergistically reduced neuropathic pain with 100-fold greater efficacy than predicted from an additive interaction. THC also synergistically enhanced the efficacy of current first-line neuropathic pain treatments gabapentin and duloxetine.”

Here in the UK, chronic pain issues are the most common reason for patients to apply for a medical cannabis prescription. Peter, a current Releaf patient, has found that his medical cannabis treatment has not only reduced the impact of his trigeminal neuralgia, but also helped him lower his opioid intake. 

What does real-world medical cannabis prescribing look like today in the UK? 

On the NHS, access to cannabis-based medicines unfortunately remains extremely limited. Epidyolex is licensed for two types of treatment-resistant paediatric epilepsy syndromes, and Sativex can be legally prescribed for MS-related spasticity, but in reality, these type of prescriptions through the NHS are rarely offered. 

This is where private medical cannabis clinics, like Releaf, have stepped in to help fill the gap. 

For patients with complex neurological symptoms who’ve tried at least two conventional treatment approaches, private clinics offer access to sometimes life-changing alternative/complementary treatment options. 

Releaf’s world-class clinical team works with patients to build treatment plans around specific symptoms, routines, and goals. While our doctors design unique treatment plans for all, most patients with neurological conditions start with a balanced THC:CBD oil or dried flower, depending on whether they need consistent coverage or fast relief. Medical cannabis oil vape pens are also now available to Releaf patients where appropriate. 

What sets Releaf care apart from the rest of the pack isn’t just access, but structure. Releaf offers guided titration, regular follow-ups, and ongoing symptom tracking to help fine-tune treatment over time.

And whilst medical cannabis is not an overnight fix, most patients report steadier symptom control, less reliance on conventional pharmaceuticals, better sleep, reduced anxiety, and more day-to-day stability. It’s not perfect, but for those who qualify, it can feel like the first time their treatment has been built around their individual health needs.

Ready to learn more? 

Head to our fast and free medical cannabis eligibility checker. It takes less than 20 seconds to complete, and once you answer the 3 questions, you’ll instantly find out if you might be eligible for a medical cannabis prescription. 

No commitment.

No pressure.

Just clear, honest, patient first guidance from the beginning.