Science Interviews


Mon, 15th Aug 2016

Why cannabis gets you stoned

Khalil Thirlaway, University of Nottingham

Listen Now    Download as mp3 from the show Drugs: Time for a Change?

Khalil Thirlaway gives an account of how marijuana can get you stoned.Cannabis

Khalil - Weed, pot, skunk. Whatever you call it cannabis is one of the most commonly used drugs in the word. It’s made from the leaves and buds of the marijuana plant and is either smoked or baked into foods and consumed. Each bud and leaf of the marijuana plant is composed of hundreds of chemicals, but there are two important ones: tetrahydrocannabinol or THC and cannabidiol or CBD. While CBD contributes to making the smoker relaxed, THC is to blame for its psychoactive effects or ‘high.’

Every time someone smokes or eats cannabis, THC seeps through the bloodstream to the brain and attaches to cannabinoid receptors. These cannabinoid receptors are part of the brain’s makeup and THC is very similar to a naturally occurring chemical called anandamide which usually binds to these receptors. THC floods your brain in much higher concentrations than the naturally occurring anandamide and causes the neurons that make up your brain to fire continuously upsetting the normal balance of your brain

So, how does a bit of excess firing cause the user to get ‘stoned’? Well, cannabinoid receptors are prolific things and found all over the brain. This means that THC can impact on lots of different functions, from memory and hunger to pain and forward planning, giving all those well known effects like the ‘munchies’ and lack of motivation. Crucially, cannabinoid receptors are also present on the brain’s reward system boosting dopamine and causing euphoria and relaxation. The activation of this reward system is thought to be the common factor in all drugs of abuse.

Marijuana is not a totally harmless herb but, with THC, there is no such thing as a fatal overdose. A study on monkeys reported that a person can gobble up to 70 grams of the drug, about 5,000 times more than you needed to get ‘high’ and still have no toxic effects. Still, if you wanted to eat your weight in weed infused treats, you might experience fragmentary thought, lack of concentration,impaired memory, drowsiness, and anxiety. Not to mention dry mouth, red eyes, and increased appetite and heart rate. Long term use has been linked to schizophrenia and memory loss, although a clear cause and effect link is yet to be found.

While it’s true that some cannabis-derived drugs have shown promise in treating anxiety, depression, post-traumatic stress disorder, epilepsy and neuropathic pain, the overall effect of marijuana on brain chemistry isn’t crystal clear and much evidence is still awaiting confirmation in clinical trials.


Subscribe Free

Related Content


Make a comment

See the whole discussion | Make a comment

Not working please enable javascript
Powered by UKfast
Genetics Society