- Addition of a single dose of cannabidiol (CBD) attenuated the functional abnormalities seen in three regions of the brain that are involved in psychosis
- This is the first study to show how cannabidiol acts in the brain to reduce psychotic symptoms.
- The results have unraveled the brain mechanisms of a new drug that works in a completely different way to traditional anti-psychotics available until now.
The abnormalities in the brain function seen in people with psychosis can be reduced by a single dose of the cannabis extract cannabidiol, reveals a new study. This research from King's College London has been published in JAMA Psychiatry
Regular use of cannabis has been shown as a risk factor for the development of psychosis and poor clinical outcomes after its onset - the short-term psychomimetic effects (mimicking the symptoms of psychosis)
are due to one of its constituents called tetrahydrocannabinol (THC)
. THC is responsible for getting users high which is linked to the development of psychosis.
‘Only one dose of the cannabis extract called cannabidiol is needed to bring down the altered responses in three regions of the brain involved in psychosis, providing the first evidence of how the drug might be acting in the brain to reduce psychotic symptoms.’
However, cannabidiol also referred to as CBD is a major non-intoxicating, non-psychoactive constituent of cannabis
that has contrasting neurological and behavioral effects (opposing effects to THC)
Clinical studies have indicated that CBD has antipsychotic and anxiolytic (anti-anxiety) properties in patients with mental disorders, including a 2017 King's College London trial that demonstrated cannabidiol's anti-psychotic properties that work in opposition to THC.
In the United States, a purified form of cannabidiol has been giving license to treat rare childhood epilepsies
. But, how exactly does the CBD work in the brain to alleviate psychosis? How does it mediate its beneficial effects? Study - To examine the effects of CBD in individuals at clinical high risk of psychosis
The study comprised of two groups:
- One group of 33 young people who yet undiagnosed with psychosis but who were experiencing distressing psychotic symptoms
- The second group of 19 healthy controls
Sixteen of the participants received a single dose of cannabidiol while the other 17 received a placebo.
The research team chose a memory task that engages three regions of the brain (medial temporal lobe or MTL, midbrain, and striatum) that were known to be involved in psychosis
The participants' brains were examined in an MRI scanner while performing the task.
- As expected, abnormal brain activity was noticed in the participants at risk of psychosis compared to the healthy participants.
- With the intervention of cannabidiol, the abnormal brain activity was less severe in those who received the drug than for those who received a placebo, giving rise to the possibility that cannabidiol can help re-adjust brain activity to normal levels.
The current study suggests that cannabidiol's influence on these three brain regions could be causing its therapeutic effects on psychotic symptoms
Dr Sagnik Bhattacharyya and colleagues from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) are now launching a large-scale, first-of-its-kind multi-center trial to investigate whether CBD can be used to treat young people at high risk of developing psychosis. Over 15,000 people in England alone present themselves with early symptoms of psychosis every year.
Despite symptoms that can be extremely severe, currently no treatments exist that can be offered to patients at high risk of psychosis because current anti-psychotic drugs
can have serious side-effects.
"There is an urgent need for a safe treatment for young people at risk of psychosis," says Dr Bhattacharyya. "One of the main advantages of cannabidiol is that it is safe and seems to be very well tolerated, making it in some ways an ideal treatment. If successful, this trial will provide definitive proof of cannabidiol's role as an antipsychotic treatment
and pave the way for use in the clinic." References :
- Sagnik Bhattacharyya, Robin Wilson, Elizabeth Appiah-Kusi, et al., "Effect of Cannabidiol on Medial Temporal, Midbrain, and Striatal Dysfunction in People at Clinical High Risk of Psychosis" JAMA Psychiatry (2018) doi:10.1001/jamapsychiatry.2018.2309