The more cannabidiol (CBD) in a strain of cannabis with THC, the lower the impairment to brain function, finds a fresh UCL-led brain imaging analysis.
“Over the last two decades, rates of addiction and psychosis linked to cannabis have been on the upswing, while at precisely the same time stronger strains of cannabis with more THC and less CBD have become increasingly prevalent,” said the study’s lead author, Dr. Matt Wall (UCL Clinical Psychopharmacology Unit and Invicro).
“We have found that CBD appears to buffer the consumer against a number of the severe effects of THC on the mind.”
There’s growing evidence that THC is implicated in addiction and cannabis-induced psychosis. CBD, on the other hand, is being researched for a range of therapeutic purposes, but the interplay between THC and CBD is not yet well-known.
In the current study, the researchers monitored brain activity at rest in 17 individuals after taking distinct strains of cannabis.
Both breeds have equal levels of tetrahydrocannabinol (THC), but among these also has elevated levels of CBD whereas another breed, a high-strength cannabis commonly known as skunk, contained negligible levels of CBD. Both strains are similar to the various strains of cannabis in common use.
The researchers discovered that the low-CBD strain diminished functional connectivity in the brain’s default style (particularly from the anterior cingulate area) and salience networks, whereas the high-CBD strain caused only a minimal disturbance to these regions, suggesting the CBD counteracts a number of THC’s damaging effects.
The salience network supports other brain networks and determines what sensory or emotional inputs we listen to, and disruptions of the network have previously been implicated in dependence and psychosis.
The researchers also discovered that the THC-induced disturbance of functional connectivity in the posterior cingulate was strongly correlated with participants’ reports of subjective experiences, like feeling more ‘stoned’ or ‘high’, implying that the mind area may be fundamental to driving cannabis’ subjective effects. This association involving the anterior cingulate and subjective effects was blocked by CBD.
The researchers say their findings add to evidence that cannabis breeds with greater CBD content may be less harmful, suggesting that CBD content of cannabis should maybe be regulated in authorities where it’s legal.
“As cannabis is becoming lawful in more areas of the world, people purchasing cannabis ought to be able to generate an educated decision about their choice of cannabis breed and be aware of the relative risks,” said Dr. Wall.
“In case CBD can restore disturbance to the salience system, this could be a neuroprotective mechanism to describe its capability to treat disorders of salience like psychosis and addiction,” added senior writer Professor Val Curran (UCL Clinical Psychopharmacology Unit).