Study: CBD Administration Increases Blood Flow to the Hippocampus
According to a new study published in the Journal of Psychopharmacology, the oral use of 600mgs of oral CBD increases cerebral blood flow to the hippocampus. The study, which was randomized and placebo-controlled, is titled The effects of acute cannabidiol on cerebral blood flow and its relationship to memory: An arterial spin labelling magnetic resonance imaging study.
For the study researchers compared the use of CBD versus placebo in 15 healthy volunteers. It was found that “acute CBD causes a significant increase in regional CBF [cerebral blood flow] to the hippocampus”. Researchers state that “If replicated, the finding that acute CBD increases CBF in the hippocampus may be relevant for hippocampal disorders, since higher resting hippocampal blood flow is associated with better memory performance.”
The study concludes by stating that: “These findings may have implications for the potential use of CBD across a range of disorders associated with hippocampal dysfunction including Alzheimer’s disease, PTSD and depression.”
The study’s full abstract states:
Background: Cannabidiol (CBD) is being investigated as a potential treatment for several medical indications, many of which are characterised by altered memory processing. However, the mechanisms underlying these effects are unclear.
Aims: Our primary aim was to investigate how CBD influences cerebral blood flow (CBF) in regions involved in memory processing. Our secondary aim was to determine if the effects of CBD on CBF were associated with differences in working and episodic memory task performance.
Methods: We used a randomised, crossover, double-blind design in which 15 healthy participants were administered 600 mg oral CBD or placebo on separate days. We measured regional CBF at rest using arterial spin labelling 3 h after drug ingestion. We assessed working memory with the digit span (forward, backward) and n-back (0-back, 1-back, 2-back) tasks, and we used a prose recall task (immediate and delayed) to assess episodic memory.
Results: CBD increased CBF in the hippocampus (mean (95% confidence intervals) = 15.00 (5.78-24.21) mL/100 g/min, t14 = 3.489, Cohen’s d = 0.75, p = 0.004). There were no differences in memory task performance, but there was a significant correlation whereby greater CBD-induced increases in orbitofrontal CBF were associated with reduced reaction time on the 2-back working memory task ( r= -0.73, p = 0.005).
Conclusions: These findings suggest that CBD increases CBF to key regions involved in 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.
Researchers for the study were affiliated with the following institutions, organizations and/or universities:
- 1Translational Psychiatry Research Group, Research Department of Mental Health Neuroscience, Division of Psychiatry, Institute of Mental Health, University College London, London, UK.
- 2Clinical Psychopharmacology Unit, Research Department of Clinical, Educational and Health Psychology, University College London, London, UK.
- 3Psychiatric Imaging Group, Medical Research Council London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK.
- 4NIHR University College Hospitals London Biomedical Research Centre, University College London, London, UK.
- 5The Traumatic Stress Clinic, St Pancras Hospital, Camden and Islington NHS Foundation Trust, London, UK.
- 6National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK.
- 7Medical Research Council London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK.
- 8Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK.
- 9Department of Psychology, University of Bath, Bath, UK.