A team of researchers from King’s College London has, for the first time, imaged the brains of patients with psychosis under the influence of cannabidiol (CBD). The study demonstrates the anti-psychotic potential of CBD, suggesting large clinical trials are necessary.
Despite a wave of CBD products hitting the market touting unsubstantiated health claims, one of the more compelling and well-researched properties of this cannabis-derived compound is its intriguing antipsychotic effects. An exploratory trial from King’s College researchers in 2017 found CBD was beneficial in patients suffering from schizophrenia-related psychosis but exactly what mechanism was at play has been unclear.
A new brain imaging study is offering valuable insights into how CBD influences the brain of a subject with psychosis. The research examined 13 patients with psychosis using a double-blind, placebo controlled, crossover design. This means each patient took part in two fMRI imaging sessions – one with a placebo and one with a dose of CBD. A healthy cohort was also studied without any drug administration, offering an effective control group.
Comparing the psychosis patients under placebo with the healthy control revealed significant differences in functional connectivity between the striatum and the hippocampus. Under the influence of CBD, however, the dysfunctional connectivity was notably reduced in the psychosis subjects.
“This study provides important insight into the brain mechanisms behind the antipsychotic effects of CBD,” explains senior author on the study, Sagnik Bhattacharyya. “It gives confidence in the antipsychotic potential of CBD by demonstrating that it targets the function of brain regions implicated in psychosis and indicating that even a single dose may ameliorate some of the brain function alterations that may underlie psychosis.”
The study suggests CBD somewhat normalizes activity in the prefrontal and mediotemporal brain regions in patients with psychosis. A temporary decrease in psychotic symptoms was also noted in the study after the single CBD dose. Bhattacharyya does caution the study’s sample size is small and much more work is needed to better understand the longer-term antipsychotic effects of CBD.
“The finding that psychotic symptoms may show a trend towards improvement in this group even after one dose of CBD is encouraging, but requires a larger scale clinical trial to investigate if the effects would continue with longer term treatment,” he says.
The research offers valuable new imaging evidence building on the growing data affirming the antipsychotic effects of CBD. This is especially useful considering the current spread of recreational cannabis legalization across the world.
A revealing epidemiological study last year identified a distinct association between increasing THC levels in common cannabis strains and higher incidences of psychotic disorders. While the links between cannabis use and schizophrenia are still a source of great debate, studies are increasingly suggesting high levels of THC can be dangerous and a balance between CBD and THC in cannabis strains is vital to balancing any negative mental health outcomes arising from frequent consumption.
Bhattacharyya points out this new imaging study will hopefully lay the foundation for future clinical trials designed to clearly establish how effective CBD can be as a clinical antipsychotic tool for treating a number of different psychiatric conditions.
“The results form an important part of the picture that scientific research is building on the effects of CBD and will help support the case for further clinical trials on the use of CBD in different stages of psychosis as well other neuropsychiatric diseases such as Parkinson's disease where a proportion of patients may also experience psychotic symptoms,” Bhattacharyya concludes.
The new study was published in the journal Psychological Medicine.
Source: King’s College London