High levels of cannabidiol (CBD) in marijuana may 'dilute' the psychoactive side-effects of tetrahydrocannabinol (THC), new research suggests.
In a study conducted in rats, researchers from Vanier College in Montreal, Quebec, Canada, found that when rodents were given a combination of CBD and THC, they behaved less anxiously than when they were given THC on its own.
They believe this is because THC causes spikes in levels of a protein called ERK, which disrupts the ability the brains of animals – and humans – to process and cope with negative emotions like stress and move past them.
In turn, this leads to increased levels of anxiety and paranoia.
The findings suggest that CBD may be able to decrease these levels.
A new study from Vanier College in Canada found that marijuana with high levels of THC compared to CBD causes levels of a protein called ERK to spike, which leads to increased anxiety (file image)
THC and CBD are both derived from the cannabis plant.
Together, they are part of the cannabinoid group of compounds found in hashish, hash oil, and most strains of marijuana.
THC is the psychoactive compound responsible for the euphoric, 'high' feeling often associated with marijuana.
The compound interacts with CB1 receptors in the central nervous system and brain and creates the sensations of euphoria and anxiety.
But CBD, which is non-psychoactive, does not fit these receptors well and is believed to be responsible for some of marijuana’s therapeutic effects such as pain relief.
Previous research has found that strains of pot with high levels of THC and low levels of CBD have increased side effects such as paranoia and anxiety.
However, the biological mechanism behind this process was not understood.
For the new study, published in the journal JNeurosci, the team split rats into three groups.
The first group was given THC on its own, the second was given a combination of THC and CBD and the third group was given neither.
Researchers found that the rodents given just THC had higher levels than normal of a protein called ERK and were more anxious.
But the rats that were given both CBD and THC behaved similarly to the control rats; both of these groups had normal levels of ERK and had less anxious behavior.
The researchers believe, based on these results, that THC activates ERK while CBD inhibits it.
One study found that ER visits related to marijuana increased by at least four-fold in Colorado after marijuana was legalized.
In 2012, doctors at UCHealth University of Colorado Hospital saw about one patient every other day with a marijuana-related issue.
By 2016, doctors were seeing two to three such patients per day.
Patients often came in with conditions such as racing hearts – which could an effect of THC increasing levels of anxiety.
Recreational marijuana is legal in 11 states and Washington, DC, and 33 states and DC have legalized medical marijuana.
A 2018 poll from the Pew Research Center found that 62 percent of Americans support legalizing marijuana, double the number from two decades ago in 2000.
Opinions of legalization differ by political party, with 69 percent of Democrats supporting it compared with 75 percent of Independents and just 45 percent of Republicans.