The psychiatric research journalÂ JAMAÂ Psychiatry has just published a new study suggesting CBD could have antipsychotic effects in individuals at clinical high risk of psychosis. The study builds off compelling prior research demonstrating CBDâ€™s therapeutic effects. Titled â€śEffect of Cannabidiol on Medial Temporal, Mid-brain, and Striatial Dysfunction in People at Clinical High Risk of Psychosis,â€ť the randomized clinical trial sheds important light not just on whether or not CBD hasÂ calming cognitive effects, but alsoÂ howÂ it produces them.
What are the neurocognitive mechanisms that underlie the putative therapeutic effects of cannabidiol in psychosis? In other words, does CBD really help treat psychosis? And if so, how? Such are the questions motivating a new study published inÂ JAMA Psychiatry.
Researchers began with the premise that cannabidiol (CBD) has antipsychotic effects in humans. Exactly how it has that effect on the brain isnâ€™t fully understood.Â Psychiatrists study the chemical reactions that lead to or stem from atypical mental states. For this study, researchers wanted to try to isolate the specific chemical alterations that give CBD its therapeutic and potentially antipsychotic effects.
To do so, the study examined the effects of CBD in 33 individuals at clinical high risk (CHR) of psychosis. Previous studies have identified the regions in the brain that become perturbed in individuals with psychosis and at CHR. So theÂ JAMA study had a hypothesis: maybe CBD attenuates, or lessens, those disturbances in the parts of the brain associated with psychosis.
The studyâ€™s 33 CHR participants were part of a double-blind randomized clinical trial with 19 healthy control individuals. Some participants received a single, 600 mg oral dose of cannabidiol; others, no CBD or a placebo. Researchers examined how the CBD affected the striatum, medial temporal cortex and midbrainâ€”the target brain regions.
The investigation revealed that all three brain regions experienced modulated activation as a result of the CBD. Using an MRI while participants performed a verbal learning task, researchers measured brain activation alongside healthy control individuals who took no CBD, and high risk patients who received a placebo. What they found was that CHR patients who took CBD had activation levels about in the middle between healthy individuals with no disturbances and CHR patients who took no CBD.
In short, CBD did have the attenuating effects researchers had hypothesized. The oral dose of cannabidiol helped normalize dysfunction in all three brain regions. And that means the study may have identified one of the mechanisms responsible for CBDâ€™s therapeutic benefits.
While the studyâ€™s findings have implications for psychiatric medicine and treating individuals at high risk for psychosis, it has wider importance for anyone interested in the effects of cannabis on mental health.
There are studies that have drawn links between regular and frequent cannabis use and the development of psychosis. Others have linked psychosis with changes to the endocannabinoid system, whether cannabinoid-stimulated or not. At the same time, research shows CBD, a non-psychoactive cannabinoid, has an almost opposite neural and behavioral effect to THC. With this latest study, scientists now know more about why that is.