Cannabis explained
Medical Cannabis and Neurological Conditions: What the Evidence Shows
Could medical cannabis help with MS, Parkinson’s, epilepsy or nerve pain? We explore what the research shows and where questions remain…
Neurological conditions affect the brain, spinal cord and nerves. They can cause very different symptoms, from muscle stiffness and spasms in multiple sclerosis to movement difficulties in Parkinson’s, seizures in epilepsy and persistent nerve pain.
Cannabis-based medicines have been studied for several of these symptoms, with mixed results. Clinical trials support the use of particular cannabis medicines to reduce muscle stiffness and spasms caused by MS, or seizures in certain rare forms of epilepsy. Some of these are available through the NHS, so that patients can receive treatment without paying privately. For Parkinson’s and long-term nerve pain, however the evidence is less certain — although patients this publication has spoken with say it helps.
Here, Cannabis Health takes look at what the research shows for each condition, which medicines have been tested and what patients and clinicians still need to know.
Multiple Sclerosis
Spasticity – muscle stiffness and involuntary spasms – is one of the symptoms for which cannabis-based treatment has stronger evidence behind it.
Sativex, a mouth spray containing THC and CBD, is available through the NHS for patients across the UK with moderate to severe MS-related spasticity when other drug treatments have not worked.
A 2022 Cochrane review of 25 randomised trials, involving 3,763 people with MS, found that cannabinoids probably helped more patients report a meaningful improvement in spasticity compared with placebo.
The reviewers were “moderately confident” about improvements in spasticity and wellbeing, but had “little confidence” in the findings for chronic nerve pain because the evidence was limited.
Parkinson’s
Researchers have investigated cannabis-based treatments for movement symptoms, pain, sleep and other difficulties associated with Parkinson’s.
Back in 2024, research and support charity Parkinson’s UK said: “There is currently a lack of good quality evidence for the safety and benefits of cannabis-based treatments for Parkinson’s. Until we have robust evidence, cannabis-based medicines cannot be approved and prescribed for Parkinson’s. But new, high quality clinical trials are starting to happen which is a huge step forward.”
That same year, a randomised trial published in Movement Disorders involving 61 people – which compared a high-CBD, low-THC oral extract with placebo over two weeks – found improvements in movement scores across both groups. However, the difference was not statistically significant, and researchers found no clear benefit from the treatment. They also reported numerous mild side effects.
Another placebo-controlled trial published in the same journal earlier this year, which enrolled 101 people with Parkinson’s and chronic pain, found that the tested CBD/THC oil did not improve pain or other non-movement symptoms compared with placebo. And of those enrolled, 87 completed the nine-week study.
Neuropathic Pain
Neuropathic pain comes from damage to, or disease affecting, the nervous system.
NICE currently advises against offering THC, THC/CBD combinations, dronabinol or nabilone for chronic pain in adults, and recommends CBD only within a clinical trial.
A Cochrane review published in January 2026, which examined 21 trials involving 2,187 adults, described their confidence in the evidence as “low to very low” and called for “larger, well-designed studies”.
But patients like Lara Smith, a former paediatric nurse from Newcastle who lives with cervical myelopathy and severe nerve pain, said that Smith said cannabis flower and CBD oil had made a “life-changing” difference after she spent years trying dozens of diffeernet medicines that gave her servere side effets so bad she almost caused a fire after…
Trigeminal Neuralgia
Trigeminal neuralgia affects the nerve carrying sensation from the face to the brain. It causes attacks of severe facial pain, often described as an electric shock.
Some patients with the condition report relief from prescribed medical cannabis, but research has not established how well it works specifically for this condition. Evidence for CBD alone is also insufficient to identify an effective product or dose.
In 2021, Cannabis Health shared the experience of Helen, a patient at Integro Medical Cannabis Clinics, who described improvements in neck tension, sleep and the severity of her facial pain after receiving prescribed cannabis.
“Even though the pain is still there, it’s much less severe, I can actually read a book or look at my computer screen for longer than I could before,” she said.
Speaking to the publication at the time, Dr Anthony Ordman, senior consultant at Integro Medical Clinics, described how he believed cannabis medicines were helping patients with the condition.
The cannabis prescriber said: “Cannabis medicines help to settle down the over-excited nerves and to dampen down their excessive firing. But then it also helps with the secondary effects of TN such as muscle tension, low mood, poor sleep and so on.”
His clinical observations, however, have not yet been supported by strong trial evidence specifically for trigeminal neuralgia.
A small US study – which reviewed the records of 42 patients receiving medical cannabis – reported that 81% described improvements, while 40% experienced side effects, including sleepiness, dizziness and nausea.
Epilepsy
Epilepsy is a condition affecting the brain that causes repeated seizures – sudden bursts of electrical activity that can affect movement, awareness and behaviour.
Patients and families affected by severe epilepsy were central to the campaign that led to the UK’s medical cannabis law change in 2018, including the families of Alfie Dingley and Billy Caldwell.
However, NHS access remains limited. Epidyolex is the only cannabis-based medicine licensed specifically for epilepsy, while NHS prescriptions for unlicensed cannabis products remain rare.
Epidyolex – an oral solution containing purified CBD – is licensed for patients aged two and older with:
- Dravet syndrome: a rare form of epilepsy that usually begins in infancy and causes difficult-to-control seizures.
- Lennox–Gastaut syndrome: a rare epilepsy beginning in childhood, involving several seizure types and often difficulties with learning and development.
- Tuberous sclerosis complex: a genetic condition causing mainly non-cancerous growths in organs, including the brain, which can lead to seizures.
For Dravet and Lennox–Gastaut syndromes, it is used alongside clobazam, another anti-seizure medicine. For tuberous sclerosis complex, it is added to other epilepsy treatments.
A 2017 double-blind trial published in the New England Journal of Medicine, involving 120 children and young adults with Dravet syndrome, compared cannabidiol with placebo alongside their existing treatment.
The median number of convulsive seizures per month fell from 12.4 to 5.9 with cannabidiol, compared with 14.9 to 14.1 with placebo. However, side effects were more frequent in the cannabidiol group.
NHS England announced in January 2023 that it would also make Epidyolex available to eligible patients with tuberous sclerosis complex.
Welcoming the decision at the time, Dr Pooja Takhar, then joint chief executive of the Tuberous Sclerosis Association, highlighted the “massive unmet need for new treatment options”.
Why the Medicine Matters
Cannabis medicines differ in their cannabinoid content, formulation, dose and how they are taken.
As pain specialist Dr Michael Überall, medical director at the private Institute of Neurological Sciences, previously told Cannabis Health: “Cannabis is not a single pharmacological substance. Different products contain different concentrations and combinations of cannabinoids and other plant constituents.”
The Evidence at a Glance
| Condition or symptom | What the evidence supports | Important limitation |
|---|---|---|
| MS-related spasticity | A role for THC/CBD spray in selected adults after other drug treatments have not worked | Symptom improvement does not establish an effect on disease progression |
| Parkinson’s | Research continues into motor and non-motor symptoms | Controlled trials discussed here did not establish benefits over placebo for their main outcomes |
| Chronic neuropathic pain | Some findings suggest modest benefits with particular preparations | Confidence in the evidence is low or very low; substantial pain relief remains uncertain |
| Certain rare epilepsies | Pharmaceutical CBD can reduce seizures in defined patient groups | Results cannot be applied to every epilepsy or other CBD products |
Continuing the Discussion in London
The Cannabis Health Symposium at Conway Hall on 26 November will explore the evidence behind cannabis-based medicines and the decisions facing clinicians in a bid to provide frontline practitioners with all the knowledge they need to practise confidently and safely.
The current programme includes Cannabis for Neurological Disorders and Neurodiversity: Fact or Fiction?, alongside discussions of pain treatment and the strengths and limitations of different types of research.
Explore the London programme and book your place here.
Frequently Asked Questions
Can Medical Cannabis Cure Multiple Sclerosis?
The evidence discussed here concerns symptom management, particularly spasticity. It does not establish that cannabis-based medicines cure MS or slow its progression.
Is CBD Proven to Help Parkinson’s?
Benefits have not been established across Parkinson’s symptoms. Results depend on the preparation and outcome studied, and the controlled trials discussed here did not demonstrate benefits over placebo for their main outcomes.
Are Cannabis Medicines Recommended for Nerve Pain?
NICE does not recommend routinely offering the cannabinoid medicines listed in its guidance for chronic pain. The 2026 Cochrane review found considerable uncertainty about benefits for neuropathic pain.
Is Prescription CBD the Same as Shop-Bought CBD Oil?
No. Evidence for a pharmaceutical CBD medicine with a defined formulation and dose cannot be assumed to apply to consumer CBD products.
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