Meta-Analysis of Study Suggests Positive Correlation in Epilepsy Treatment with Cannabinoids

A series of new studies suggests the possible benefit of cannabinoids in the treatment of those with epilepsy.

A Quick Into to Epilepsy

Epilepsy is a general term that falls under the category of seizure disorders, which are disorders that affect the electrical activity of the brain. Neurons, which transmit electrical signals to different areas of the brain, are responsible for helping to regulate the control we have over our mental and physical actions. During a seizure, this regulation is disrupted due to the neurons in our brain becoming too ‘excited.’

Some forms of epilepsy arise in childhood whereas others may take time to manifest. Epilepsy is a lifelong condition that can have the potential to have a severely adverse effect on the quality of life of an individual. Treatment can include the use of medication (pharmacological treatment) or non-pharmacological treatment.

An Overview of the Study:

A comprehensive review of data was collected and interpreted from a series of 52 previous studies. Each of the individual studies sought to document the relationship between cannabis and epilepsy treatment, and the findings of the collective analysis of all of these studies was published in the medical journal Neurology and Neuroscience reports (Gaston, T.E. & Szaflarski, J.P. Curr Neurol Neurosci Rep (2018) 18: 73.

There were several metrics of data collected and interpreted within this meta-analysis, namely:

  1. Potential indirect modulation of the endocannabinoid receptors by CBD via blocking the breakdown of anandamide. Anandamide is a neurotransmitter enzyme within the brain that has relevance to the mechanism of seizures. Being a neurotransmitter, it connects signals between neurons (nerve cells) in the brain that are responsible for control of movement, memory, and cognition.
  2. Searching the literature for other seizure-relevant targets of CBD, including:
    • CBDs activation of the transient receptor potential of vanilloid type-1 (TRPV1).
      • This is a particular type of ion-channel that is involved in transmitting and modulating the feeling of pain within the body.
    • CBDs antagonist action at GPR55.
      • GPR55 is a type of “G-protein coupled receptor” that exists within the body that is activated by certain chemical compounds. This particular G-protein receptor is a possible target for the treatment of pain and inflammation.
    • CBDs effect on abnormal sodium channels and the blockade of T-type calcium channels
      • Sodium and calcium channels exist within the brain and are extremely important in the understanding of seizure disorders. If these channels become activated abnormally, or are interfered with in any way, it can severely disrupt normal functioning of the brain, and therefore the rest of the body, as seen in a seizure.
    • Modulation of adenosine receptors, voltage-dependent anion-selective channel protein (VDAC1), and tumor necrosis factor alpha (TNF-a) release
      • These are all components that mediate signaling transmission and pain reception/ inflammation throughout the body
  3. Analysis of “artisanal” CBD products used in treatment for patients with epilepsy
  4. Collection of data from open-label expanded access programs (EAPs) and randomized placebo-controlled trails (RCTs) of a highly purified oral preparation of CBD
  5. Data on adverse effects and drug-drug interactions with highly purified CBD

Initial Results:

After analyzing the data from the 52 studies, there was evidence to show a link between CBD use in epileptic patients and a decrease in both seizure frequency and intensity.

Possible Side-effects:

The side-effects of taking CBD were overall very mild, with the most commonly reported being sedation and diarrhea. Overall CBD was found to be well-tolerated.

Negative Drug Interactions:

There was one notable drug interaction between CBD and Clobazam, a medication in the benzodiazepine class of drugs that is used in epileptics to decrease electrical activity in the brain during a seizure. It was postulated (theorized?) during the meta-analysis that this could potentially be due to CBD’s inhibition of a particular metabolite (CYP2C19) within the metabolic system that exists within the liver (Cytochrome p-450 system) that is used to process most pharmaceutical medications. The inhibition of this particular metabolite by CBD increased the level of Clobazam in patients taking both drugs.

Implications from the Study

Meta-analysis are vital in extracting important data from a conglomerate of selected research studies in order to draw conclusions and map trends that would otherwise remain hidden within each of the individual selected studies. This particular comprehensive literature review examined many studies in order to draw a conclusion regarding the efficacy of CBD in the treatment of epilepsy patients, i.e. whether CBD can be shown to have a positive benefit in the lives of those who suffer from epilepsy, including some of whom have not responded to any prior treatments. Or whether CBD treatment may actually, conversely, have an adverse effect on those with epilepsy. Or if, in fact, there is no real notable correlation between CBD and epilepsy at all.

In this particular instance, I see a very positive future regarding the role of CBD in the treatment of epileptic patients. According to this highly comprehensive review, the potential benefits of CBD are to be taken note of, whereas the drawbacks are few and far in-between.

Limitations & Drawbacks

There are several limitations of the study itself which have a certain potential to reduce the validity of the trends noted in the meta-analysis. One such limitation is the notable conflict of interest by several of those who participated in this analysis, who were also, at the time of publication, receiving personal fees from GW pharmaceuticals, a British pharmaceutical company specializing in cannabinoid medicines.

Regarding drawbacks of the studies used in the analysis, some studies were conducted after the fact and others had patients respond via survey. These forms of data collection in research studies can potentially open the door to bias, and therefore decreased validity of the data collected. There were also certain aspects of studies that were not controlled, such as the dosage and preparation of CBD used in treatment. In other instances, this information was simply unknown.


This is certainly a very exciting literature review, as it gives way to the possibility of a new hope for so many of those who suffer from epilepsy. That hope could show itself, quite possibly, in the form of CBD. The only way we can draw a firm conclusion regarding the potential of cementing CBD within the future of epilepsy treatment is to continue to do more research. The more research we do, the closer that future becomes.

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Ed is a writer and marketer who has been involved with the cannabis industry since 2017. He is particularly passionate about helping small businesses succeed in the increasingly corporate-takeover environment of the cannabis industry, as well as helping people get started working with cannabis.

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