scholarly journals The Impact of Cannabidiol on Human Brain Function: A Systematic Review

2021 ◽  
Vol 11 ◽  
Author(s):  
Albert Batalla ◽  
Julian Bos ◽  
Amber Postma ◽  
Matthijs G. Bossong

Background: Accumulating evidence suggests that the non-intoxicating cannabinoid compound cannabidiol (CBD) may have antipsychotic and anxiolytic properties, and thus may be a promising new agent in the treatment of psychotic and anxiety disorders. However, the neurobiological substrates underlying the potential therapeutic effects of CBD are still unclear. The aim of this systematic review is to provide a detailed and up-to-date systematic literature overview of neuroimaging studies that investigated the acute impact of CBD on human brain function.Methods: Papers published until May 2020 were included from PubMed following a comprehensive search strategy and pre-determined set of criteria for article selection. We included studies that examined the effects of CBD on brain function of healthy volunteers and individuals diagnosed with a psychiatric disorder, comprising both the effects of CBD alone as well as in direct comparison to those induced by ∆9-tetrahydrocannabinol (THC), the main psychoactive component of Cannabis.Results: One-ninety four studies were identified, of which 17 met inclusion criteria. All studies investigated the acute effects of CBD on brain function during resting state or in the context of cognitive tasks. In healthy volunteers, acute CBD enhanced fronto-striatal resting state connectivity, both compared to placebo and THC. Furthermore, CBD modulated brain activity and had opposite effects when compared to THC following task-specific patterns during various cognitive paradigms, such as emotional processing (fronto-temporal), verbal memory (fronto-striatal), response inhibition (fronto-limbic-striatal), and auditory/visual processing (temporo-occipital). In individuals at clinical high risk for psychosis and patients with established psychosis, acute CBD showed intermediate brain activity compared to placebo and healthy controls during cognitive task performance. CBD modulated resting limbic activity in subjects with anxiety and metabolite levels in patients with autism spectrum disorders.Conclusion: Neuroimaging studies have shown that acute CBD induces significant alterations in brain activity and connectivity patterns during resting state and performance of cognitive tasks in both healthy volunteers and patients with a psychiatric disorder. This included modulation of functional networks relevant for psychiatric disorders, possibly reflecting CBD’s therapeutic effects. Future studies should consider replication of findings and enlarge the inclusion of psychiatric patients, combining longer-term CBD treatment with neuroimaging assessments.

2020 ◽  
Author(s):  
Sreejan Kumar ◽  
Cameron T. Ellis ◽  
Thomas O’Connell ◽  
Marvin M Chun ◽  
Nicholas B. Turk-Browne

AbstractThe extent to which brain functions are localized or distributed is a foundational question in neuroscience. In the human brain, common fMRI methods such as cluster correction, atlas parcellation, and anatomical searchlight are biased by design toward finding localized representations. Here we introduce the functional searchlight approach as an alternative to anatomical searchlight analysis, the most commonly used exploratory multivariate fMRI technique. Functional searchlight removes any anatomical bias by grouping voxels based only on functional similarity and ignoring anatomical proximity. We report evidence that visual and auditory features from deep neural networks and semantic features from a natural language processing model are more widely distributed across the brain than previously acknowledged. This approach provides a new way to evaluate and constrain computational models with brain activity and pushes our understanding of human brain function further along the spectrum from strict modularity toward distributed representation.


2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S195-S196
Author(s):  
A Thomann ◽  
M Schmitgen ◽  
D Kmuche ◽  
M Griebe ◽  
M Ebert ◽  
...  

Abstract Background Fatigue is common in patients with inflammatory bowel diseases (IBD). It occurs in up to 80% of patients with active disease, but also a considerable proportion of patients in remission, and significantly affects quality of life. The underlying mechanisms are still poorly understood, and it is still unclear which patients will suffer from fatigue even in luminally quiescent disease. Task-based brain functional studies have examined neural correlates of fatigueability and found changes in the orbitofrontal cortex (OFC), among other regions. To the best our knowledge, the relationship between brain function and fatigue in IBD has not been investigated. This study aimed to examine the association between fatigue and resting-state brain function in remitted IBD patients. Methods We obtained resting-state-functional MRI (rs-fMRI) data from 45 IBD patients in stable remission without current steroid or biological therapy and 17 healthy controls (HCs). Fatigue was assessed with Würzburger Erschöpfungsinventar Multiple Sklerose (WEIMuS). Preprocessing of rs-fMRI-data and calculation of amplitude of low frequency fluctuations (ALFF) was performed using the Data Processing Assistant for rs-fMRI. The resulting individual maps were analysed via second-level SPM multiple regression models in patients and HC to test for correlations between ALFF data and WEIMuS scores. Age, gender and mean framewise displacement were included as covariates of no interest and results were displayed at p < 0.001 (peak level) with a threshold of spatial extent (k) according to the expected voxels per cluster estimated by SPM. Results Fatigue scores did not differ significantly between patients and controls (mean WEIMuS-scores 17.9 (SD 13.9) vs. 12.3 (SD 16.5), p = .17). Proportions of participants with fatigue scores above the cutoff (>32P.) were nearly identical in patients and HC (8/45 vs. 3/17). In patients, fatigue scores correlated positively with ALFF in the right central operculum and negatively with ALFF in the left OFC and left cerebellum (all p < .001, Figure 1). Fatigue and ALFF in the left cerebellum were also found to correlate in HC. Conclusion This study shows fatigue-associated changes in brain activity in several brain regions. The negative association between fatigue and ALFF in the left OFC of IBD patients was not seen in HC, indicating that reduced ALFF in the OFC may represent a neural correlate of IBD-related fatigue. The OFC is thought to be involved in decision-making, which is described to be impaired in many fatigued IBD patients. If the association between fatigue and brain function detected in our study is confirmed in longitudinal IBD studies, these regions could serve as biomarkers when targeting fatigue in IBD.


2016 ◽  
Vol 113 (11) ◽  
pp. 3066-3071 ◽  
Author(s):  
Christelle Meyer ◽  
Vincenzo Muto ◽  
Mathieu Jaspar ◽  
Caroline Kussé ◽  
Erik Lambot ◽  
...  

Daily variations in the environment have shaped life on Earth, with circadian cycles identified in most living organisms. Likewise, seasons correspond to annual environmental fluctuations to which organisms have adapted. However, little is known about seasonal variations in human brain physiology. We investigated annual rhythms of brain activity in a cross-sectional study of healthy young participants. They were maintained in an environment free of seasonal cues for 4.5 d, after which brain responses were assessed using functional magnetic resonance imaging (fMRI) while they performed two different cognitive tasks. Brain responses to both tasks varied significantly across seasons, but the phase of these annual rhythms was strikingly different, speaking for a complex impact of season on human brain function. For the sustained attention task, the maximum and minimum responses were located around summer and winter solstices, respectively, whereas for the working memory task, maximum and minimum responses were observed around autumn and spring equinoxes. These findings reveal previously unappreciated process-specific seasonality in human cognitive brain function that could contribute to intraindividual cognitive changes at specific times of year and changes in affective control in vulnerable populations.


2021 ◽  
Vol 43 ◽  
pp. 101329
Author(s):  
Padmavathi Kora ◽  
K. Meenakshi ◽  
K. Swaraja ◽  
A. Rajani ◽  
Mantena Satyanarayana Raju

2020 ◽  
Author(s):  
Bingxin Zhao ◽  
Tengfei Li ◽  
Stephen M. Smith ◽  
Di Xiong ◽  
Xifeng Wang ◽  
...  

AbstractThe human brain remains active in the absence of explicit tasks and forms networks of correlated activity. Resting-state functional magnetic resonance imaging (rsfMRI) measures brain activity at rest, which has been linked with both cognitive and clinical outcomes. The genetic variants influencing human brain function are largely unknown. Here we utilized rsfMRI from 44,190 individuals of multiple ancestries (37,339 in the UK Biobank) to discover and validate the common genetic variants influencing intrinsic brain activity. We identified hundreds of novel genetic loci associated with intrinsic functional signatures (P < 2.8 × 10−11), including associations to the central executive, default mode, and salience networks involved in the triple network model of psychopathology. A number of intrinsic brain activity associated loci colocalized with brain disorder GWAS (e.g., Alzheimer’s disease, Parkinson’s disease, schizophrenia) and cognition, such as 19q13.32, 17q21.31, and 2p16.1. Particularly, we detected a colocalization between one (rs429358) of the two variants in the APOE ε4 locus and function of the default mode, central executive, attention, and visual networks. Genetic correlation analysis demonstrated shared genetic influences between brain function and brain structure in the same regions. We also detected significant genetic correlations with 26 other complex traits, such as ADHD, major depressive disorder, schizophrenia, intelligence, education, sleep, subjective well-being, and neuroticism. Common variants associated with intrinsic brain activity were enriched within regulatory element in brain tissues.


2017 ◽  
Vol 3 (20;3) ◽  
pp. 139-154 ◽  
Author(s):  
Mira Meeus

Background: Chronic musculoskeletal pain is characterized by maladaptive central neuroplastic changes. Many observational studies have demonstrated that chronic pain states are associated with brain alterations regarding structure and/or function. Rehabilitation of patients with chronic musculoskeletal pain may include cognitive, exercise, or multimodal therapies. Objective: The current review aims to provide a constructive overview of the existing literature reporting neural correlates, based on brain magnetic resonance imaging (MRI) techniques, following conservative treatment in chronic musculoskeletal pain patients. Study Design: Systematic review of the literature. Methods: The current review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Literature was searched from 3 databases and screened for eligibility. Methodological quality across studies was assessed with Cochrane Collaboration’s tool for assessing risk of bias and quality of evidence was determined applying the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach. Results: A total of 9 eligible studies were identified with a predominant high risk of bias. Cognitive behavioral therapy induced several structural and functional changes predominantly in prefrontal cortical regions and a shift from affective to sensory-discriminative brain activity after behavioral extinction training. Multidisciplinary treatment in pediatric complex regional pain syndrome facilitated normalization of functional connectivity of resting-state networks and the amygdala, and increased gray matter in prefrontal and specific subcortical areas. Exercise therapy led to specific for resting-state functional connectivity and a trend towards pressure-induced brain activity changes. Limitations: A very small number of studies was available, which furthermore exhibited small study samples. Moreover, only 2 of the included studies were randomized controlled trials. Conclusions: It is likely that conservative treatments may induce mainly functional and structural brain changes in prefrontal regions in patients with chronic musculoskeletal pain. Due to the relatively high risk of bias across the included studies, future studies with randomized designs are needed to confirm the current findings. In addition, more research evaluating the treatmentinduced effects on white matter and whole-brain network dynamics are warranted. Key words: Chronic pain, musculoskeletal pain, MRI, functional MRI, therapy, rehabilitation, cognitive behavioral therapy, exercise therapy


2020 ◽  
Author(s):  
Elisabeth S. May ◽  
Cristina Gil Ávila ◽  
Son Ta Dinh ◽  
Henrik Heitmann ◽  
Vanessa D. Hohn ◽  
...  

AbstractChronic pain is a highly prevalent and severely disabling disease, which is associated with substantial changes of brain function. Such changes have mostly been observed when analyzing static measures of brain activity during the resting-state. However, brain activity varies over time and it is increasingly recognized that the temporal dynamics of brain activity provide behaviorally relevant information in different neuropsychiatric disorders. Here, we therefore investigated whether the temporal dynamics of brain function are altered in chronic pain. To this end, we applied microstate analysis to eyes-open and eyes-closed resting-state electroencephalography (EEG) data of 101 patients suffering from chronic pain and 88 age- and gender-matched healthy controls. Microstate analysis describes EEG activity as a sequence of a limited number of topographies termed microstates, which remain stable for tens of milliseconds. Our results revealed that sequences of 5 microstates, labelled with the letters A to E, described resting-state brain activity in both groups and conditions. Bayesian analysis of the temporal characteristics of microstates revealed that microstate D has a less predominant role in patients than in healthy participants. This difference was consistently found in eyes-open and eyes-closed EEG recordings. No evidence for differences in other microstates was found. As microstate D has been previously related to attentional networks and functions, abnormalities of microstate D might relate to dysfunctional attentional processes in chronic pain. These findings add to the understanding of the pathophysiology of chronic pain and might eventually contribute to the development of an EEG-based biomarker of chronic pain.


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