We've updated our Privacy Policy to make it clearer how we use your personal data.

We use cookies to provide you with a better experience, read our Cookie Policy

Analytical Cannabis Logo
Home > News > Science & Health > Content Piece

Medical Cannabis Can Reduce Epileptic Seizures By 97 Percent, Study Finds

By Alexander Beadle

Published: Dec 21, 2020   
Listen with
Register for FREE to listen to this article
Thank you. Listen to this article using the player above.

In a new study of ten medical cannabis patients, researchers from Imperial College London have found cannabis-based medicinal products (CBMPs) to provide effective seizure relief to patients with a range of epileptic conditions – not just the two drug-resistant epilepsies currently covered by British prescribing guidelines.

Their findings also indicate that CBMPs can decrease the number of other concurrent antiepileptic drugs (AEDs) needed for seizure control and supports the view that combination CBD and THC treatments can be effective in seizure control where CBD alone is not.

CBMPs reduce average monthly seizures by 97 percent

The patient data used in the study were taken from a database operated by the charity End Our Pain, which included information on the patients’ age, diagnoses, treatments, and the frequency of seizures pre- and post-CBMP treatment. The caregivers of the patients were also invited to comment on any changes to quality of life or adverse side effects experienced by the patients.

Five of the patients experienced seizures, but they did have some form of undiagnosed epilepsy. Three had been diagnosed with Lennox-Gastaut syndrome, one with cardiofaciocutaneous (CFC) syndrome, and one with Doose syndrome – also known as myoclonic-astatic epilepsy. Four of the patients had previously been given CBD to try to control their seizures to no success.

After starting treatment with a CBMP containing THC and CBD, the monthly seizure frequency in each patient fell dramatically, from between 37-to-18,000 seizures per month to 0-to-750 seizures. On average, the number of monthly seizures fell by 97 percent while using CBMPs as an add-on medication. With CBMP treatment, the average number of concurrent AEDs needed to control each individual’s seizures also fell, going from an average of eight medications to just one.

Additionally, the caregivers of the patients reported seeing improvements in insomnia, cognitive ability and function, emotional regulation, speech, and in the frequency of panic attacks. In one case, the improvements were so great that one patient was allowed to leave institutional care for the first time in a decade.

The need for more general research

These findings might seem extreme, but they are in line with other similar studies on combination CBD and THC treatments for controlling epileptic seizures. A 2006 Israeli study using 20:1 CBD:THC oil saw improvements in seizure frequency in 66 of the 74 children enrolled, with over half experiencing a more than 50 percent reduction in seizure frequency, and nearly one-in-five seeing a 75-100 percent drop-off in seizures.

But while other studies already exist in the literature to support the use of CBMPs in epilepsy, the researchers behind this new study say that this one is uniquely important for two main reasons.

Firstly, past studies tended to narrowly focus on only one or two types of epilepsy, whereas this one encompasses a wider range. But it is also fairly common to set general dosage regimens that each patient enrolled in a study like this must follow.

As the Imperial College researchers point out, this is contrary to current clinical practice where patients tend to start on low doses of THC and higher doses of CBD, which can then be adjusted based on patient response. The researchers decided to keep this study open to a wide range of conditions while also allowing for individual dosing regimens to be set and monitored, in order to better reflect a general clinical population.

Limitations on research and access in the UK

In 2018, the UK amended its Misuse of Drugs Regulations 2001 to allow for certain cannabis-based medicinal products (CBMPs) to be prescribed by specialists to patients in need, effectively legalizing medical cannabis treatment.

But strict prescription guidelines handed down by bodies such as the National Institute for Clinical and Healthcare Excellence (NICE) have generally limited the prescription of CBMPs for treating seizures to just one CBD formulation – and even then, only to treat two rare forms of severe treatment-resistant epilepsy. 

Such guidelines make it extremely hard for patients to access CBMPs that could otherwise improve their conditions. Just last month, campaigners spoke out about the refusal of the National Health Service (NHS) to provide CMBPs to children with epilepsy, as just three prescriptions for combination CBD:THC cannabis oil have been issued through the NHS since they were legalized two years ago. A spokesperson for the Department of Health and Social Care told BBC News that “more evidence is needed to routinely prescribe and fund other treatments on the NHS” but that the department was continuing to “back further research.”

Rayyan Zafar, a PhD candidate at Imperial’s Department of Brain Sciences and one of the authors behind the new study, said in a press statement that “patients and their families deserve better, so we implore policy makers, regulators and public health bodies to prioritize the health of these individuals and help them to access the NHS medicines which are making a dramatic improvement to their lives.”

The Imperial College London researchers recognize that their new study is not the sort of randomized and controlled clinical study that is normally taken as the “gold standard” by governing bodies; the study of these ten patient records is more like a series of n = 1 trials. However, they argue that the treatment of every individual patient in medicine is essentially an n = 1 trial, and so in lieu of any randomized trials the ten-case series should still provide a strong evidence base for specialists to explore.


Like what you just read? You can find similar content on the topic tag shown below.

Science & Health

Stay connected with the latest news in cannabis extraction, science and testing

Get the latest news with the FREE weekly Analytical Cannabis newsletter