A single dose of cannabidiol helped increase blood flow to the hippocampus, an important area of the brain associated with memory and emotion, finds a new study from a team led by Dr. Michael Bloomfield.
Cannabidiol (CBD) is being investigated as a potential treatment for several medical indications, many of which are characterized by altered memory processing.
The latest research published in the Journal of Psychopharmacology found that CBD causes a significant increase in cerebral blood flow (CBF), which may have implications for the potential use of CBD across a range of disorders associated with hippocampal dysfunction.
Hippocampus is a brain structure embedded deep in the temporal lobe of each cerebral cortex, which regulates motivation, emotion, learning, and memory. The role of the hippocampus in memory depends on its functional and structural connection with cortex and, especially, with higher-order perceptual areas, where memory is eventually stored.
A team lead by Dr. Michael Bloomfield from the University of College London (UCL) aimed to investigate how CBD influences cerebral blood flow in regions involved with memory processing. Also, they tried to determine if the effects of CBD on CBF were associated with the differences in working and episodic memory task performance.
During the trial, 15 healthy participants were administered 600 mg oral CBD or placebo on separate days. The scientists measured regional CBF 3 hours after drug ingestion. The working memory was assessed with the digit span task, n-back task, and prose recall task.
Participants were recruited through online adverts, posters, and word-of-mouth. All participants were right-handed and aged 18–70. None of them have previously used cannabis or CBD.
Great potential for Alzeheimer’s disease
The findings suggest that CBD increases CBF to key regions involved with memory processing, particularly the hippocampus. These results identify potential mechanisms of CBD for a range of conditions associated with altered memory processing, including Alzheimer’s disease, schizophrenia, post-traumatic stress disorder, and cannabis-use disorders.
Several preclinical models already offered evidence to suggest that CBD may improve memory impairment across multiple domains, including working and episodic memory, and in cognitive impairment caused by the other main constituent of cannabis, ∆9-tetrahydrocannabinol (THC).
This is the first study to find that CBD increases blood flow to key regions involved with memory processing, particularly the hippocampus. The finding supports the view that CBD has region-specific hemodynamic effects in the human brain, which has previously been disputed. This finding may be particularly relevant to Alzheimer’s disease, where there are defects in blood flow control.
However, the precise mechanisms underlying the effects of CBD on memory still stay unclear. Regional CBF is strongly associated with brain volume change and has a complex bidirectional relationship. Since acute CBD may increase hippocampal CBF, further studies are required to investigate whether CBD can attenuate the hippocampal structural alterations, including atrophy, and hippocampal-dependent memory impairments associated with these disorders.
This notion is supported by findings that CBD can rescue hippocampal atrophy and improve episodic memory performance in chronic cannabis users.