A new study shows that smoking cannabis deadens the brain’s reward centre hormone and makes them want more to get the same high. This can increase the risk of addiction
Most people think that cannabis is not addictive and that it should be made legal in the UK, while other argue that it is a gateway to harder, potentially dangerous drugs.
A new study has found the drug dulls the release of hormone dopamine meaning users have to smoke more to get the same high.
This change increases the risk of getting addicted to cannabis – or other drugs, experts say.
Cannabis More Addictive Than You Think
Neuroscientist Dr Mary Heitzeg, of Michigan University, said: “Some people may believe marijuana/cannabis is not addictive or it’s ‘better for your health’ than other drugs that can cause dependence.
“But this study provides evidence it’s affecting the brain in a way that may make it more difficult to stop taking the drug.
“Cannabis changes your brain in a way that may change your behaviour – and where you get your sense of reward from.”
People would normally get a little ‘rush’ out of the idea they’re about to win some money.
Brain scans showed at that moment there is a burst of activity in the area that responds top rewards.
But the study for the first time discovered users get less of a buzz when they win cash – and their joy gets even more dampened over time.
It found measurable changes in the brain’s reward system with marijuana use – even when other factors like drinking and cigarette smoking were taken into account.
Dr Heitzeg also added: “What we saw was over time marijuana use was associated with a lower response to a monetary reward.
“This means something that would be rewarding to most people was no longer rewarding to them, suggesting but not proving their reward system has been ‘hijacked’ by the drug, and that they need the drug to feel reward – or their emotional response has been dampened.”
The study of 108 participants in their early 20s – found the more they smoked the less pleasure they felt when winning money.
In anticipating a reward, the cells of the nucleus accumbens usually activate, producing the chemical dopamine.
The bigger the response, the more pleasure or thrill a person feels – and the more likely they’ll be to repeat the behaviour later.
Psychologist Dr Elisa Trucco, of Florida International University, said: “We are all born with an innate drive to engage in behaviours that feel rewarding and give us pleasure.
“We now have convincing evidence regular marijuana use impacts the brain’s natural response to these rewards.
“In the long run, this is likely to put these individuals at risk for addiction.”
The participants – three-quarters of whom were men – had their brain scans at three points over four years while playing a game that asked them to click a button when they saw a target on a screen in front of them.
Before each round they were told they might win 20 cents or $5 – or they might lose that amount or have no reward or loss.
has been made legal in 25 US states for recreational or medical purposes.
Cannabis is the most widely used illegal drug in the UK with 6.7% of adults aged 16 to 59 using it in 2014 to 2015.