22nd Jun 2018

Medical cannabis: what does the science say?

22nd Jun 2018

Curated by A S M Mainul Hasan

cannabis-oil-editRecent studies confirm that the symptoms of severe epilepsy can be eased by medical cannabis, free from the THC compound that induces highs. However, there is still insufficient evidence to suggest its regular use in children.

In 10 seconds? The universally legal version of medical cannabis can reduce seizures in epilepsy sufferers. Researchers, on the other hand point out that, even products without THC – a substance illegal in some countries – can have side-effects. (Read the science)

So, what exactly was discovered? Scientists added two doses of CBD (cannabidiol) containing drops to the daily epilepsy medication of Lennox-Gastaut syndrome sufferers. They’ve found that the higher dose – 20 mg per kilogram of body weight – cut the number of seizures by 42% on average. (Read the paper here)

I thought cannabis wasn't legal? Well, products containing THC (which makes you high) are not legal in many places. Others, containing CBD, which doesn't alter the patient's mental state, are allowed. What makes the question about the legality of medical marijuana tricky is the fact that THC and CBD both have medical benefits, but for different things. (More on the biochemical processes of THC and CBD activity)

And what are those benefits? THC-containing marijuana helps MS and cancer patients by lowering inflammation, pain, muscle contraction and boosts appetite. CBD on the other hand can be used to treat epilepsy, mental illness and addictions. Interestingly THC works best when combined with CBD – but this would mean having a medication with a substance banned in many places. (Find out more on THC and CBD)

How about the drawbacks? THC obviously makes you high. It can affect the provisional memory and judgment, cause hallucinations, delusions, depression and anxiety. With CBD, epileptic patients experience less seizures, but more drowsiness, decreased appetite, diarrhoea, upper respiratory tract infection, fever and vomiting compared to using placebo drugs. (More on the effects of medical marijuana)

Parents of severely epileptic children want legalisation. Is science on their side? Well, we need to balance the anecdotal experience of child patients getting better from medical cannabis with hard science. We still need conclusive evidence about the benefits of marijuana and a way to eliminate its adverse effects. This is why most doctors continue to discourage its use for children. With the impending legalisation of recreational cannabis in Canada, researchers also warn about the adverse changes THC can cause in young peoples' developing brains. (Read more)


Medical cannabis: what is legal, what is not?

Canada announced that it will complete the legalisation process of cannabis by 17th October, 2018, while medical cannabis products are legal in many EU countries and nearly half of US states.

These products can be  pills, liquids or vaporisers.

The US has so far approved two pills that contain THC, used to treat nausea in cancer patients and to elevate appetite in AIDS patients.

The UK is currently reviewing medicinal marijuana rules following the furore around 12 year-old Billy Caldwell, a severe epilepsy sufferer, whose cannabis oil imported from Canada was confiscated.

In the EU, currently only Austria, the Czech Republic, Finland, Germany, Italy, Portugal, Poland and Spain allow marijuana to be used as a medicine. 


(Psst, Mainul distilled 14 research papers to save you 862.2 min)

Curated by

A S M Mainul Hasan

PhD student in Molecular Plant Genetics at the University of Tasmania, Australia and MA in Agrobiotechnology

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