A Guide to Cannabis and Epilepsy

One little girl in the US experienced incredible relief from taking cannabis for her epileptic seizures. Could it help you too?


  • Currently, cannabis is only found effective in reducing epilepsy in Lennox-Gastaut Syndrome and Dravet syndrome
  • While there is some promising research, there are also drug interactions with anti-seizure medications and side effects to be managed
  • It’s theorised that THC may reduce production of arachidonic acid in the brain
  • CBD may block signals carried by lysophosphatidylinositol (LPI). This chemical is hijacked in the brain and may result in seizures

In 2012, four year old Charlotte Figi was experiencing up to 50 tonic-clonic seizures per day. After treatment with high THC/low CBD medicinal marijuana, she was only getting four per month. So, can epilepsy be cured with cannabis?

What is Epilepsy?

When people imagine epilepsy, they imagine someone falling to the ground and having a ‘fit’ type seizure. While these seizures do happen, they aren’t the case for all. There are different types of seizures, including but not limited to:

  • Tonic-clonic (grand mal), where people fall, lose consciousness, and have muscle spasms
  • Absence seizures (petit mal), where people may stare off into space, sometimes rapidly blinking, ‘zoning out’
  • Simple focal seizures, where the person may twitch, feel a change in sensation like a strange smell or taste
  • Complex focal seizures, where the person is confused and dazed, unable to respond to outside stimuli for a few minutes

All of these seizures are caused by disturbances in the brain; it could be imbalance of neurotransmitters, presence of a tumour, or brain damage, but the end result is abnormal electrical impulses in the brain. Instead of continuous electrical signal, there’s a lightning burst between areas or cells in the brain, which causes the seizures. The type of seizure depends on the area of the brain that is affected, and the severity.

There’s no known cause of epilepsy, only about 30% of sufferers can trace their disease genetically. Things like brain damage, infections, immune disorders, stroke, and various other disorders can cause epilepsy, but also not.

What Cures Epilepsy?

About 30% of epilepsy can’t be ‘cured’, but with treatment, some people do become seizure free. This can be via:

  • Anti-seizure medications
  • The ketogenic diet with low carbohydrate intake can be effective in reducing seizures
  • Surgery, including removal or destruction of problematic tissue, or cutting the fibres that connect areas of the brain

Avoiding triggers can be an impossible task; avoiding driving past poplar trees in winter sun, having sufficient sleep when looking after a child, avoiding alcohol, the list can be endless.

What About CBD, THC and Epilepsy?

Currently, there are medications based on cannabis which are purportedly treatments of epilepsy. There is Sativex (in NZ use of this THC and CBD mouth spray for epilepsy is considered unapproved and off label), and Epidiolex (which the oral spray has been approved by the FDA in the USA).

Use of this is complicated; it’s only considered effective for children with Lennox-Gastaut Syndrome and Dravet syndrome. It seems effective for this sub-group of epilepsy sufferers; one study found that the number of seizures dropped 43.9% from baseline.

But this flash of hope has evolved into more studies, which are under way to assess:

  • The appropriate ratio of CBD to THC to effective treatment
  • The most effective dosage
  • The easiest and most successful method of use
  • The use of cannabis in other epilepsy types

A NZ/Australia study found that transdermally administered cannabidiol in drug-resistant focal epilepsy yielded some positive results. While the seizure frequency remained the same at week 12, those who continued treatment experienced a 50% decrease in seizures at the six month mark.

A small 2023 study found that children with drug-resistant epilepsy responded to CBD and THC use, with half the patients noting a 50% drop in seizure activity.

Why Could Cannabis Treat Seizures?

An epileptic seizure triggers the creation and release of a natural chemical in our brain called 2-arachidonoylglycerol (2-AG). This is quickly released upon seizure outset and works to dampen down the intensity of the seizure. This is of interest because it is an endocannabinoid that mimicks THC. Endocannabinoids, in general, seem to inhibit excessive excitement in the brain, being released when the excitatory neurons exceed a threshold. The endocannabinoid system is known to help maintain homeostasis in our bodies.

However, the rapidity of the breakdown of 2-AG following its use in the brain results in more confusion and amnesia after the seizure. This is because it converts to arachidonic acid which can cause inflammation and constriction of blood vessels in the brain. It’s theorised that a medication which stops 2-AG’s conversion to arachidonic acid will not only stop that harmful blood vessel constricting, but also increase the concentration of 2-AG.

One theory is that by that introducing THC and/or CBD into the brain could work like 2-AG but without the rapid disintegration of it, helping to manage the seizures long term and minimising disorientation after a seizure.

Another theory is that CBD blocks signals carried by lysophosphatidylinositol (LPI), which can be hijacked and used to create seizures. This too signals that CBD could be used as a preventative medication.

Should Cannabis Be Treated with Caution as an Epilepsy Treatment?

In short, yes. While a lot of research is promising, there are a number of side effects listed too, and up to half of trial participants experience more seizures or different types of seizures, sleeplessness, and a decline in development. It’s also important to note that THC should never be administered to young children.

However, when treatment is by an experienced and skilled medicinal marijuana practitioner, there could be benefits. Starting with a low dose and slowly increasing the amount can help to find the point where there’s therapeutic benefit, but little to no side effects.

Cannabis can interact with existing medication, so it’s very important to be prescribed with caution and understanding of the situation. In particular, cannabis can interact with antiseizure medications. However, if you have drug-resistant seizures, cannabis may offer improvement and improve your quality of life.

Sign up to our Newsletter