Effects of cbd on the brain
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Effects of CBD on the Brain
Cannabidiol (CBD) and Brain Function: An Overview
Cannabidiol (CBD), a non-intoxicating compound found in cannabis, has garnered significant attention for its potential therapeutic effects on various neuropsychiatric disorders. Research has shown that CBD can influence brain function in multiple ways, impacting areas related to anxiety, psychosis, and neurodevelopmental disorders.
CBD and Anxiety Reduction
Anxiolytic Properties and Brain Activity
Several studies have demonstrated that CBD possesses anxiolytic (anxiety-reducing) properties. Functional neuroimaging studies have shown that CBD decreases subjective anxiety and increases mental sedation in healthy volunteers. This effect is mediated by changes in regional cerebral blood flow (rCBF) in brain areas such as the left amygdala-hippocampal complex, hypothalamus, and left posterior cingulate gyrus 25. These findings suggest that CBD's anxiolytic effects are linked to its action on limbic and paralimbic brain regions.
CBD and Psychosis
Antipsychotic Effects and Brain Connectivity
CBD has shown promise as an antipsychotic agent. In individuals at clinical high risk of psychosis, CBD has been found to normalize brain activity in regions such as the parahippocampal gyrus, midbrain, and striatum during cognitive tasks 6. This normalization of brain function is thought to underlie CBD's therapeutic effects on psychotic symptoms. Additionally, in patients with established psychosis, CBD has been observed to attenuate dysfunction in the prefrontal and mediotemporal regions, as well as improve mediotemporal-striatal connectivity 10.
CBD and Autism Spectrum Disorder (ASD)
Modulation of Brain Activity
Research on the effects of CBD in individuals with autism spectrum disorder (ASD) has shown that CBD can alter brain activity and connectivity. Specifically, CBD increases the fractional amplitude of low-frequency fluctuations (fALFF) in the cerebellar vermis and right fusiform gyrus, with significant changes primarily observed in the ASD group 3. These alterations in brain activity suggest that CBD may have potential therapeutic benefits for individuals with ASD.
CBD and Neurotransmitter Systems
Glutamate and GABA Modulation
CBD's impact on neurotransmitter systems, particularly glutamate and gamma-aminobutyric acid (GABA), has been a focus of research. Studies using magnetic resonance spectroscopy (MRS) have shown that CBD can modulate levels of these neurotransmitters in the brain. In neurotypical individuals, CBD increases subcortical glutamate and GABA levels, while in individuals with ASD, it decreases cortical GABA levels 4. These findings indicate that CBD can differentially affect excitatory and inhibitory neurotransmitter systems depending on the presence of neurodevelopmental disorders.
Neuroprotection and Neurogenesis
Synaptic Plasticity and Neurogenesis
CBD has been found to have neuroprotective effects, which include promoting synaptic plasticity and facilitating neurogenesis. These effects are thought to be mediated through multiple pharmacological targets, including the endocannabinoid system 89. In animal models, CBD has been shown to prevent the anxiogenic effects of chronic stress by enhancing hippocampal neurogenesis and dendritic remodeling, primarily through the activation of CB1 and CB2 receptors 9.
Conclusion
The research on CBD's effects on the brain highlights its potential as a therapeutic agent for various neuropsychiatric disorders. CBD's ability to modulate brain activity, neurotransmitter systems, and promote neurogenesis underscores its promise in treating conditions such as anxiety, psychosis, and autism spectrum disorder. Future studies should focus on long-term effects and the mechanisms underlying these therapeutic benefits to fully harness CBD's potential in clinical settings.
Sources and full results
Most relevant research papers on this topic
The Impact of Cannabidiol on Human Brain Function: A Systematic Review
Acute CBD alters brain activity and connectivity patterns during resting state and cognitive tasks in both healthy volunteers and patients with psychiatric disorders, potentially reflecting its therapeutic effects.
Systematic ReviewEffects of Cannabidiol (CBD) on Regional Cerebral Blood Flow
CBD has anxiolytic properties, mediated by actions on limbic and paralimbic brain areas, suggesting its potential therapeutic use for anxiety and depression.
RCT
Rigorous Journal
Highly CitedThe effect of cannabidiol (CBD) on low-frequency activity and functional connectivity in the brain of adults with and without autism spectrum disorder (ASD)
CBD alters regional low-frequency activity and functional connectivity in the brain, particularly in regions implicated in autism spectrum disorder (ASD).
RCT
Very Rigorous JournalEffects of cannabidiol on brain excitation and inhibition systems; a randomised placebo-controlled single dose trial during magnetic resonance spectroscopy in adults with and without autism spectrum disorder
CBD modulates glutamate-GABA systems, but prefrontal-GABA systems respond differently in individuals with autism spectrum disorder compared to controls.
RCTVery Rigorous JournalHighly CitedNeural basis of anxiolytic effects of cannabidiol (CBD) in generalized social anxiety disorder: a preliminary report
CBD reduces anxiety in patients with generalized social anxiety disorder, likely due to its effects on limbic and paralimbic brain areas.
RCTVery Rigorous JournalHighly CitedEffect of Cannabidiol on Medial Temporal, Midbrain, and Striatal Dysfunction in People at Clinical High Risk of Psychosis: A Randomized Clinical Trial
CBD has antipsychotic effects in people at high risk of psychosis, with its effects mediated through neurocognitive mechanisms in the brain.
RCTHighly CitedEffects of the Acute and Chronic Administration of Cannabidiol on Cognition in Humans and Animals: A Systematic Review.
Chronic and acute administration of CBD does not impair cognition in humans without neuropsychiatric disorders, and preclinical studies show promising results for its effects on animal cognition.
Systematic ReviewCannabidiol, neuroprotection and neuropsychiatric disorders.
Cannabidiol (CBD) shows potential therapeutic effects in neuropsychiatric disorders by attenuating brain damage, reducing psychotic-, anxiety-, and depressive-like behaviors, and promoting neurogenesis through multiple pharmacological targets.
Rigorous JournalHighly CitedThe anxiolytic effects of cannabidiol in chronically stressed mice are mediated by the endocannabinoid system: Role of neurogenesis and dendritic remodeling
CBD prevents the anxiogenic effects of Chronic Unpredictable Stress in mice by activating CB1/CB2 receptors, promoting neurogenesis and dendritic remodeling.
Non-RCT
Animal StudyRigorous JournalHighly CitedNormalization of mediotemporal and prefrontal activity, and mediotemporal-striatal connectivity, may underlie antipsychotic effects of cannabidiol in psychosis
CBD's antipsychotic effects in psychosis patients may be based on normalizing mediotemporal and prefrontal dysfunction and mediotemporal-striatal functional connectivity.
RCTRigorous Journal