Cannabis has been a major medicinal, ceremonial, and industrial crop in global communities for decades. Its widespread use was based not only on cultural knowledge but also on its empirically proven capacity for improving various mental and physical health conditions. This ability is partly due to the endocannabinoid system’s (ECS) widespread distribution in the brain.
While many of cannabis’s brain effects are good, others have sparked concerns about potential risks. In efforts to better understand and minimize those risks, researchers are gearing up to discern how cannabis influences the brain.
Scientists recruiting subjects to study the brain on cannabis
A research collaboration between Folium Biosciences and FutureCeuticals needs recruits for studying the effects of cannabis on the brain. Particularly, scientists are investigating how one of the major active cannabinoids, cannabidiol (CBD), influences the brain.
Despite extensive research into the herb and its psychoactive attributes, few studies have investigated this particular compound. Most scientists have focused on CBD’s counterpart, tetrahydrocannabinol (THC), which provides the “high” that many recreational users seek.
At present, scientists are confident in recent findings showing that “CBD has shown no evidence of abuse or dependence potential.” Still, further studies are needed to strengthen certainty.
The sudden influx of CBD products – especially relatively unregulated health supplements – into the market has experts especially concerned. Rampant dishonest and misleading advertising can be hazardous to public health, as consumers may be exposing themselves to medical risks not yet understood.
To begin closing the knowledge gap, Jennifer L. Robinson, Ph.D., and Ryan T. Bird, M.S., of Auburn University are seeking 15 participants between 21-50 years old for a clinical trial. They estimate that they’ll complete the project by April 15, 2022, with a tentative start date of July 6, 2021.
Investigating CBD’s brain effects
Robinson and Bird plan to administer two treatments throughout the experiment:
- CBD tincture: This will contain 125 mg broad-spectrum CBD oil at a concentration of about 7 percent. Additional ingredients include 24 mg sunflower lecithin, 56 mg peppermint oil, 1,661 mg hempseed oil (comprising the majority of the tincture at 89 percent). Study participants will consume the tincture orally, holding it in their mouths for 45 seconds before swallowing.
- Placebo: Participants in this group received daily doses of a tincture with a nearly identical ingredient profile, except for CBD. Still, they were required to consume the treatment according to the same routine: Hold for 45 seconds, then swallow.
The control group is essential to developing objective conclusions about CBD’s brain effects. Additionally, the triple-blind assessment design will prevent any incidental bias in determining how effective CBD is compared to the placebo.
A “triple-blind” design means that the participant, researchers, and results assessors are all unaware of which treatments contain CBD and which are only the placebo.
Once each study subject has received their tincture, the researchers will test for various cognitive or behavioral signs that might indicate cannabis’s influence on the brain. Specifically, they’ll monitor:
- Behavioral changes after CBD consumption
- Fluctuations in neurometabolite levels (Neurometabolites are compounds that indicate biochemical activity in the brain. Abnormal concentrations are usually associated with psychiatric disorders like bipolar disorder and schizophrenia.)
- Functional connectivity between nerve cells
- Changes in the blood oxygen levels at a resting state
- Responses to emotional stimuli
Robinson and Bird seem to be confident in CBD’s reported benefits so far, citing its capacity for alleviating symptoms from pain, insomnia, and anxiety. At the same time, they recognize the urgent need for further details on CBD’s brain impacts.
Other researchers have already delved into the matter. Yet, they’ve only just scratched the surface.
What scientists already know about CBD and the brain
One of the clearest points of empirical knowledge about cannabis is its tendency to affect developing brains more adversely than adults’. Cannabinoid receptors, particularly CB1, are widely distributed. You can find them in the hippocampus, prefrontal cortex, and many other regions.
Now, these are reliable therapeutic targets for managing mental health in adulthood. However, they are also liabilities in the adolescent brain with cannabis use.
CB1 receptors grow in number during adolescence. During this time, they directly influence genetic expression regulating neural development. So, scientists think that consuming cannabis during this time can essentially cause a domino effect of brain development issues.
Joanna Jacobus and Susan F. Tapert of the VA San Diego Healthcare System state, “[M]arijuana use could significantly alter… neurochemical communication and genetic expression of neural development, [and cause] a toxic effect on brain tissue.” These effects will ripple throughout the nervous system, potentially impairing physical and cognitive functioning.
Still, interactions between cannabis and the brain are not so black-and-white. Studies have yielded pretty mixed results demonstrating CBD’s and THC’s effects on humans’ cognitive processes. Some major findings include:
- Neuronal connectivity increases in the orbitofrontal cortex (OFC). The OFC is a part of the brain responsible for controlling impulses, making decisions, and learning. This can be detrimental to cognitive health since more connectivity requires more glucose, taking about 70 percent of the brain’s energy.
- Grey matter in the OFC fell with THC-rich cannabis use. Grey matter makes up the brain’s outermost layer, playing a central role in humans’ daily biological functioning, including movement, memory, and experiencing emotions. Scientists believe the greater connectivity mentioned above might be an adaptation to less grey matter.
- CBD may be beneficial to white matter, particularly in managing its mitochondrial activity, antioxidant processes, and neuroprotection (preventing cell death). On the other hand, THC may be detrimental to the OFC, potentially disrupt “synaptic pruning,” or the removal of extra, unnecessary synapses (points of information transfer between nerve cells, or neurons.)
Researchers have only unveiled the tip of the glacier of cannabis-brain interactions. Like the upcoming project headed by Robinson and Bird, future studies will provide greater context for the herb’s cognitive effects.
One of the major factors underlying widespread hesitance to accept cannabis as a medical treatment is the lack of research into its potential effects on the brain. Current knowledge shows that cannabis can have both beneficial and adverse effects, depending on the primary cannabinoid.
Unfortunately, the mixed results are not enough to resolve lingering uncertainties. Hopefully, Jennifer Robinson’s and Ryan Bird’s study will help unravel the remaining mysteries of cannabis-brain interactions.