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Neural basis of anxiolytic effects of cannabidiol (CBD) in generalized social anxiety disorder: A preliminary report

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Animal and human studies indicate that cannabidiol (CBD), a major constituent of cannabis, has anxiolytic properties. However, no study to date has investigated the effects of this compound on human pathological anxiety and its underlying brain mechanisms. The aim of the present study was to investigate this in patients with generalized social anxiety disorder (SAD) using functional neuroimaging. Regional cerebral blood flow (rCBF) at rest was measured twice using (99m)Tc-ECD SPECT in 10 treatment-naïve patients with SAD. In the first session, subjects were given an oral dose of CBD (400 mg) or placebo, in a double-blind procedure. In the second session, the same procedure was performed using the drug that had not been administered in the previous session. Within-subject between-condition rCBF comparisons were performed using statistical parametric mapping. Relative to placebo, CBD was associated with significantly decreased subjective anxiety (p < 0.001), reduced ECD uptake in the left parahippocampal gyrus, hippocampus, and inferior temporal gyrus (p < 0.001, uncorrected), and increased ECD uptake in the right posterior cingulate gyrus (p < 0.001, uncorrected). These results suggest that CBD reduces anxiety in SAD and that this is related to its effects on activity in limbic and paralimbic brain areas.
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... In the same line, tricyclic antidepressants which are still prescribed thoroughly may also induce harmful metabolic syndrome and lethal arrhythmias in some vulnerable anxious patients [33]. In that sense, several ongoing clinical trials are on their way elsewhere with regard to the anxiolytic effects of CBD and other CBMFs [34][35][36]. Thereby, we consider our RWE preliminary results on long-term treatment for UAD continue to nurture and unravel available data with regard to CBD anxiolytic effects. The mechanisms by which CBD decreases anxiety levels seem to be related to modulation of the limbic and paralimbic brain areas [34]. ...
... Thereby, we consider our RWE preliminary results on long-term treatment for UAD continue to nurture and unravel available data with regard to CBD anxiolytic effects. The mechanisms by which CBD decreases anxiety levels seem to be related to modulation of the limbic and paralimbic brain areas [34]. Previously, it has been suggested that the inhibition of fatty acid amide hydrolase enzyme mediated by CBD, increases the concentration of anandamide which impact on adenosine function, and may interact to some extent with 5-HT 1A receptors [35]. ...
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Introduction: Preclinical and clinical evidence has elucidated that cannabis-based medical formulations (CBMFs) may display anxiolytic, antidepressive, and neuroprotective properties. CBMFs are often considered as novel therapeutic anxiolytic agents that can be prescribed as pharmacotherapy for symptomatic domains in anxiety disorders (ADs). Our aim was to explore effectiveness and tolerability of enriched cannabidiol (CBD) oil extract formulations in adults with anxiety symptoms in an outpatient mental health program in Colombia during the COVID-19 pandemic. Methods: We conducted an observational, retrospective, real-world evidence case series from electronic health records at Zerenia Clinic in Bogotá, Colombia between June 2021 and December 2022. Our convenience sample consisted of people searching for CBMFs for the treatment of anxiety symptoms. A cohort of 24 adults was prescribed with enriched CBD in the form of non-sterile oral liquids suspended in sesame seed oil extracts for DSM-5 unspecified anxiety disorder and followed throughout the first year of treatment. CBMFs were prepared by dissolving full-spectrum cannabis extracts in sesame seed oil to a standardized concentration of active ingredients which is CBD-enriched. The oil extract contained 100 mg/mL of CBD and less than 1.9 mg/mL of THC. Primary outcome measures established were the anxiety subscale in the Hospital Anxiety and Depression Scale (HADS-A), and the clinical global impression scale with regard to severity (CGI-S) and improvement (CGI-I) at baseline, 6 months, and 12 months during follow-up. Secondary outcome measures established were HADS depression subscale (HADS-D) and the Epworth Sleepiness Scale (ESS), respectively. Participants also completed the patient-reported outcome measures (PROMs) during each visit throughout the 12-month follow-up. PROMs documented both participantʼs subjective improvement experience and progressive adverse effects. Results: After 6 months of treatment with sublingually administered enriched CBD oil extracts in a median dosage of 100 mg, more than half (54.17%) of the sample continued to report significant anxiety symptoms. After 12 months, only 37.50% persisted with significant anxiety symptoms with a median dose of 120 mg of enriched CBD oil extracts. Similar subjective improvements were reported with regard to sleep disturbances (SDs) as a secondary outcome. At baseline, less than half (46.83%) of the sample reported significant daytime sleepiness. After 6 months of enriched CBD oil extract treatment, less than one third (29.17%) continued to report SDs. At end point, a high proportion of the sample (87.50%) were considered to have normal daytime sleepiness. The cohort showed no clinically relevant depressive symptoms at baseline based on HADS-D scores; therefore, no improvement could be reported throughout the 12-month follow-up. Minimal gender differences with regard to HADS-D scores may be attributed to modifying effects of menopause-related symptoms. No significant adverse drug reactions or deaths were reported during the 12-month follow-up. Conclusions: Further research should determine the long-term efficacy, safety, and appropriate dosages of enriched CBD oil extracts in treating specific ADs rather than broad and unspecified anxiety symptoms. The state of the art of CBMFs for ADs should be warranted by future randomized controlled trials. The next stage for cannabis research should be focused in performing head-to-head trials comparing enriched CBD extracts or capsules versus first-line treatments proven to be effective in ADs.
... Indeed, open-label trials that have assessed the use of CBD for the treatment of anxiety disorders tend to suggest a significant clinical benefit (Berger et al., 2022;Dahlgren et al., 2022), while the outcomes of randomized double-blind studies assessing CBD's potential anxiolytic effects when compared to a placebo control tend to be more mixed. For example, although CBD has been reported to acutely blunt subjective anxiety in some doubleblinded placebo-controlled studies (Bergamaschi et al., 2011;Crippa et al., 2011), other studies found no effect of CBD versus placebo on various indices of anxiety (Arndt and de Wit, 2017;Gournay et al., 2023a;Hundal et al., 2018;Stanley et al., 2023). Because these studies did not assess perceived drug assignment, it is not clear to what extent strong placebo effects obscure drug effects in negative trials and/or contribute to putative therapeutic effects in positive trials. ...
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Background Cannabidiol (CBD) impacts brain regions implicated in anxiety reactivity and stress reactivity (e.g., amygdala, anterior cingulate cortex (ACC), anterior insula (AI)); however, placebo-controlled studies are mixed regarding CBD’s anxiolytic effects. We previously reported that CBD expectancy alone can alter subjective, physiological, and endocrine markers of stress/anxiety; however, it is unclear whether these findings reflect altered brain reactivity. This study evaluated whether CBD expectancy independently alters amygdala resting-state functional connectivity (rsFC) with the ACC and AI following acute stress. Method Thirty-eight (20 females) healthy adults were randomly assigned to receive accurate or inaccurate information regarding the CBD content of a CBD-free oil administered during a single experimental session. Following a baseline resting state MRI scan, participants administered their assigned oil sublingually, engaged in a stress task (serial subtraction with negative feedback) inside the scanner, and underwent another resting state MRI scan. Amygdala rsFC with the ACC and AI was measured during each scan, and the subjective state was assessed at six time points. Outcomes were analyzed using ANCOVA. Results CBD expectancy (vs CBD-free expectancy) was associated with significantly weaker rsFC between the left amygdala and right ACC ( p = 0.042), but did not systematically alter amygdala-AI rsFC ( p-values > 0.05). We also replicated our previously reported CBD expectancy effects on subjective stress/anxiety in the scanner context. Conclusion CBD placebo effects may be sufficient to alter neural responses relevant to its purported anxiolytic and stress-relieving properties. Future work is needed to replicate these results and determine whether CBD expectancy and pharmacology interact to alter neural anxiety reactivity and stress reactivity.
... Further, when evaluating cannabinoid dosage and mood outcomes across all three of the product groups, higher doses of THC were associated with a tension increase. These results are in agreement with previous research supporting that CBD is an effective anxiolytic and can reduce negative affect (Zuardi et al., 2017;Crippa et al., Frontiers in Pharmacology frontiersin.org 10 2011), whereas THC can be anxiogenic in a dose-dependent manner (Sharpe et al., 2020;Rosário et al., 2024;Lichenstein, 2022). ...
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Introduction Cannabis, commonly known for both therapeutic and intoxicating effects, is gaining accessibility on legal markets and traction as a potential alternative therapy for pain mediation, particularly in those suffering from chronic low back pain. However, the effectiveness in this population of legal market forms of cannabis, particularly commonly used edibles, is unknown. Methods Therefore, this study utilized a naturalistic prospective design where participants with chronic low back pain with intentions to initiate cannabis use for treatment were recruited and self-selected edible cannabis products containing varying amounts of delta- 9 tetrahydrocannabinol (THC) and cannabidiol (CBD). Products were categorized as CBD-dominant, THC-dominant, or combined THC and CBD (THC + CBD). Results 249 participants [140 female (56.62%), mean (SD) age of 46.30 (16.02), 90% White] were tracked over 2 weeks of ad libitum use and assessed during a naturalistic acute cannabis administration session on changes in pain, mood, and subjective drug effects. During acute administration, a significant correlation between THC dose and short-term pain relief was found, suggesting that higher THC doses were associated with greater pain reduction (p < .05). In addition, THC was associated with higher levels of subjective cannabis drug effects (p < .001), regardless of whether CBD was also in the edible product. Acute CBD dose was primarily associated with short-term tension relief (p < .05); however, there were no associations between CBD dose and acute pain. Over the 2-week ad libitum administration period results suggested pain reductions across participants using all forms of cannabis. However, trends suggested that more frequent use of CBD-dominant edible cannabis may be associated with greater reductions in perceived pain over the 2-week observation period (p = .07). Discussion These findings support the short-term analgesic effects of THC and anxiolytic effects of CBD and further suggest that orally-administered THC and CBD should continue to be evaluated for the potential to provide both acute and extended relief from chronic low back pain. Clinical Trial Registration https://clinicaltrials.gov/study/NCT03522324?locStr=Boulder,%20CO&country=United%20States&state=Colorado&city=Boulder&cond=chronic%20low%20back%20pain&intr=Cannabis&rank=1, identifier NCT03522324.
... One body of evidence supports that THC and THC analogues act as pro-psychotic agents [62][63][64][65][66][67][68]. There is another body of evidence in nonhuman animals that indicate that antipsychotic drugs and cannabinoid agents share many effects in common [91][92][93], studies in people with schizophrenia which show reductions in symptoms with THC treatments [69,94], and evidence from imaging studies [95][96][97]. ...
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