Cannabidiol presents an inverted U-shaped dose-response curve in a simulated public speaking test

The effects of a brand-specific, hemp-derived cannabidiol product on physiological, biochemical, and psychometric outcomes in healthy adults: a double-blind, randomized clinical trial

BACKGROUND

Cannabidiol (CBD) is a non-psychoactive phyto-cannabinoid derived from the Cannabis sativa plant. CBD exhibits various interactions at receptor sites, prompting the research of its potential anti-inflammatory, immunomodulatory, psychological, and pain-relieving effects. This study aimed to investigate the physiological, biochemical, and psychometric effects of a brand-specific, hemp-derived CBD product in healthy adults over a 12-week observation period.

METHODS

54 healthy males and females (age = 25 ± 7y; BMI = 24.82 ± 3.25 kg/m2) recruited from a large Southeastern University completed the study. Participants arrived at the laboratory after > 8 h of fasting, and > 48 h without alcohol consumption and vigorous exercise. Following baseline measurements (height, weight, blood pressure, electrocardiogram (ECG), and blood work), participants were stratified by sex and randomized to either CBD or placebo groups. Products were administered double-blinded, with both given in liquid form containing medium-chain triglyceride oil, while the CBD product specifically contained 50 mg/mL of CBD. Participants were instructed to consume 1 mL of their product twice daily and were given enough product to last until their next laboratory visit. Data were collected at baseline and on days 30 ± 3, 60 ± 3, and 90 ± 3. Blood was drawn for analysis of immune and inflammatory biomarkers. Chronic pain among participants was calculated using urine samples according to the foundational pain index (FPI). Self-reported psychometric questionnaires were utilized (Cohen's Perceived Stress Scale, Pittsburgh Sleep Quality Index, Profile of Mood States,10-item Likert scale for perceived pain) to assess stress, sleep quality, mood state, and body discomfort. To determine overall wellbeing, participants completed a daily survey indicating if they missed work or school due to illness. Change from baseline was calculated for each measure, and mixed effects models were used to determine differences between groups over time while adjusting for baseline values (α = 0.05). Data are presented as mean ± standard deviation.

RESULTS

There were no Group-by-Time interactions or Group or Time main effects for immune or inflammatory biomarkers (p > 0.05). Analyses revealed no Group-by-Time interactions or main effects observed for perceived stress, sleep quality, overall mood disturbance, and all the profile of mood state subscales (p > 0.05), except "vigor-activity." A Time main effect was found for the sub-score for "vigor-activity" (p = 0.007; Pre CBD = 19.5 ± 5.2, Post CBD = 17.3 ± 5.3; Pre PL = 19.0 ± 5.7, Post PL = 17.9 ± 7.1), which decreased from Visit 3 to Visit 4 (p = 0.025) and from Visit 3 to Visit 5 (p = 0.014). There was a Group main effect for FPI (p = 0.028; Pre CBD = 11.9 ± 14.4, Post CBD = 8.8 ± 10.9; Pre PL = 9.0 ± 14.2, Post PL = 12.9 ± 11.5), indicating that the placebo group had greater increases in pain over the intervention compared to the CBD group. No significant differences were found between groups in the incidence and prevalence of "colds or flus" (p > 0.05).

DISCUSSION

CBD was safe and well tolerated in healthy adults. These findings show pain was lower in the CBD group, suggesting a potentially positive effect for consumption of CBD. "Vigor-activity" decreased across the intervention, which may be a confounding effect of the academic semester. While the dosage chosen was safe, more research may be warranted using higher doses as these may be needed to observe further therapeutic effects in healthy populations.

Effect of preoperative oral cannabidiol-rich Cannabis extract on anxiety and postoperative pain after endodontic treatment: A double-blind randomized clinical trial

INTRODUCTION

The aim of the present study was to evaluate the effectiveness of cannabidiol-rich Cannabis extract in reducing anxiety and postoperative pain in patients submitted to endodontic treatment METHODS: The study was carried out after approval by the Research Ethics Committee (Registration No. 5.075.961). The following groups were tested: cannabidiol (CBD) and placebo. Pain was measured using a Visual Analog Scale (VAS) before the start of treatment and 24, 48 and 72 h and 7 days after the session. Anxiety was assessed using the Modified Dental Anxiety Scale and a VAS, before and immediately after treatment. In addition, salivary cortisol was measured before drug administration and after anesthesia. Data were analyzed descriptively using absolute frequencies and percentages, with a 5% margin of error.

RESULTS

The mean anxiety scores were higher in the Cannabidiol group than in the placebo group in each assessment (pre: 5.06 versus 3.07, respectively; post: 4.61 versus 2.60). However, there was no significant difference in the reduction of dental anxiety at the beginning of the consultation and throughout the procedure. We did not find statistically significant differences in postoperative pain between the Cannabidiol and placebo groups at any of the time points.

CONCLUSION

There was no evidence of an exposure-response relationship between the intervention and control groups. However, more studies are needed to determine clinical outcomes.

Review of the current ongoing clinical trials exploring the possible anti-anxiety effects of cannabidiol

BACKGROUND

Anxiety disorders (ADs) are a complex group of mental disorders and majorly contribute to the global health-related burden. Symptoms and clinical management differ widely depending on the specific diagnosis. There is a need for new, more effective pharmacological treatments for these patients as many patients do not respond to treatment and treatment is not available for several types of AD. The increased interest in the potential effects of cannabidiol (CBD) on symptoms of AD has led to several preclinical and clinical studies that suggest that CBD may be effective in some patients with AD. However, it remains unclear whether and how CBD can be used in the clinical management of ADs due to a lack of sufficiently robust clinical evidence.

COMPARATIVE EVALUATION

This narrative review provides a critical analysis of the current state of the art for ADs and summarizes six recently completed and 22 currently ongoing clinical trials investigating the effects of CBD on ADs or anxiety. The aim was to examine whether the ongoing trials are likely to provide the necessary solid evidence, or whether new studies with more robust design parameters can help to overcome the prevailing lack of solid clinical data for this CBD indication. Most of the trials reviewed are considered exploratory and do not focus on specific types of clinical anxiety or ADs as the primary condition studied. Participant numbers, CBD dose, treatment duration, and CBD formulation vary widely among the studies, and all but two are single-center studies.

CONCLUSION

For an effective clinical management of ADs using CBD, there is a need for sufficiently powered and appropriately designed clinical trials (RCT, multicenter, defined doses and exposure monitoring, robust primary outcomes) investigating the effect of CBD in specific ADs, such as social anxiety disorder and panic disorder, or in post-traumatic stress disorder.

Cannabidiol modulates contextual fear memory consolidation in animals with experimentally induced type-1 diabetes mellitus

OBJECTIVES

In view of the neuroprotective characteristic of cannabidiol (CBD) and its beneficial action on aversive memory in non-diabetic animals, we aimed to investigate in animals with experimentally induced type-1 diabetes mellitus (T1DM) whether CBD treatment would be able to impair the contextual fear memory consolidation, its generalisation and whether the effect would be lasting. We also investigated the CBD effect on anxiety-like responses.

METHODS

After T1DM induction, animals received single or more prolonged treatment with CBD and were submitted to the contextual fear conditioning test. As expression of activity-regulated cytoskeletal-associated (Arc) protein is necessary for memory consolidation, we evaluated its expression in the dorsal hippocampus (DH). For evaluating anxiety-related responses, animals were submitted to the elevated plus maze test (EPMT), in which the time and number of entries in the open arms were used as anxiety index.

RESULTS

A single injection of CBD impaired the contextual fear memory consolidation and its generalisation, which was evaluated by exposing the animal in a neutral context. This single injection was able to reduce the elevated expression of Arc in the DH from these animals. Interestingly, more prolonged treatment with CBD also impaired the persistence of context-conditioned fear memory and induced an anxiolytic-like effect, as the treated group spent more time in the open arms of the EPMT.

CONCLUSION

CBD interferes with contextual fear memory and the dosage regimen of treatment seems to be important. Moreover, we cannot rule out the involvement of emotional aspects in these processes related to fear memory.

The anxiolytic effects of cannabinoids: A comprehensive review

Cannabinoids, notably cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), have emerged as promising candidates for anxiety disorder treatment, supported by both preclinical and clinical evidence. CBD exhibits notable anxiolytic effects with a favourable safety profile, though concerns regarding mild side effects and drug interactions remain. Conversely, THC, the primary psychoactive compound, presents a range of side effects, underscoring the importance of careful dosage management and individualized treatment strategies. So far there are no FDA approved cannabinoid medications for anxiety. The review highlights challenges in cannabinoid research, including dosage variability, variable preclinical data, and limited long-term data. Despite these limitations, cannabinoids represent a promising avenue for anxiety management, with the potential for further optimization in formulation, dosing protocols, and consideration of interactions with conventional therapies. Addressing these challenges could pave the way for novel and personalized approaches to treating anxiety disorders using cannabinoid-based therapies.

Cannabidiol Oil Ingested as Sublingual Drops or Within Gelatin Capsules Shows Similar Pharmacokinetic Profiles in Healthy Males

Introduction: Cannabidiol (CBD) is a nonintoxicating phytocannabinoid used in clinical treatments and sold widely in consumer products. CBD products may be designed for sublingual or oral delivery, but it is unclear whether either is advantageous for CBD absorption. This study compared CBD pharmacokinetics after providing CBD oil as sublingual drops and within orally ingested gelatin capsules, at a dose relevant to consumer products. Materials and Methods: Eight males completed three conditions in a participant-blinded, randomized crossover design. Participants received the following combinations of placebo and CBD-containing (69 mg/mL) hemp oil in capsules and as sublingual drops: placebo capsules/placebo drops (Placebo), CBD capsules/placebo drops (CBD-Caps), and placebo capsules/CBD drops (CBD-Drops). Blood samples, blood pressure, and subjective scales were obtained/completed hourly for 6 h and at 24 h. Discussion: Plasma CBD concentrations were not different between CBD-Caps and CBD-Drops (interaction effect p=0.76). Peak CBD concentration (28.0±15.6 vs. 24.0±22.2 ng/mL), time of peak CBD concentration (4±1 vs. 4±2 h), and area under the concentration curve (45.3±20.3 vs. 41.8±23.3 ng/mL·6 h) were not different between conditions (p≥0.25). Cardiometabolic outcomes (plasma glucose/triacylglycerol, heart rate, blood pressure), liver function (plasma alanine aminotransferase/aspartate aminotransferase), kidney function (plasma creatinine), and subjective feelings/symptoms were not different between conditions (p≥0.07). Conclusions: Plasma CBD profiles were comparable between CBD-Caps and CBD-Drops, suggesting that there were not meaningful differences in routes of CBD absorption between conditions. This implies that CBD oil delivered sublingually is swallowed before oral mucosal CBD absorption occurs, which may have implications for research design, CBD product design, and consumer product choice.

Therapeutic potential of cannabidiol (CBD) in anxiety disorders: A systematic review and meta-analysis

Cannabidiol (CBD), as one of the phytocannabinoids, has a wide range of therapeutic properties for various neuropsychiatric disorders due to central nervous system effects. These therapeutic properties demonstrated by preclinical and clinical studies encompass more than just anticonvulsant, anti-arthritic, analgesic, anti-inflammatory, antioxidant, antitumor, antiemetic, antipsychotic and neuroprotective effects. It has been hypothesized that CBD holds potential in the treatment of various neuropsychiatric and anxiety disorders. Thus, PRISMA was used as a guide for our systematic review. Eight of the 1550 articles screened in June 2023 were eligible for meta-analysis. Based on the 316 participants included in these eight articles, this meta-analysis revealed a substantial significant impact of CBD on anxiety with a considerable effect size (Hedges' g = -0.92, 95% CI -1.80 to -0.04). In addition, this meta-analysis focuses on the efficacy of CBD in treating anxiety disorders such as generalized anxiety disorder (GAD), social anxiety disorder (SAD), and post-traumatic stress disorder (PTSD). However, caution should be exercised in interpreting our findings due to the limited size of the clinical sample, and additional trials ought to be carried out if deemed necessary.

The effect of nightly use of 150 mg cannabidiol on daytime neurocognitive performance in primary insomnia: a randomized controlled pilot trial

RATIONALE

Cannabidiol (CBD) is increasingly used as a sleep aid for insomnia; yet neurocognitive and subjective state effects following daily therapeutic use are unclear.

OBJECTIVES

To measure the effect of daily CBD use on neurocognitive performance and daily subjective mood in a population with primary insomnia.

METHODS

This study used a randomized, placebo-controlled, parallel design incorporating a single-blind placebo run-in week followed by a two-week double-blind dosing period, during which participants consumed 150 mg CBD (N = 15) or placebo (N = 15) sublingually 60-minutes daily before bed. Attention, executive function, reasoning, information processing, working and episodic memory were assessed using the CogPro system at the beginning of the placebo run-in, after 1-week and 2-weeks of dosing. Subjective states using visual analogue scales and side effects were recorded daily.

RESULTS

Cognitive performance was unaffected by nightly CBD supplementation (all p > 0.05). From baseline to trial conclusion, those receiving CBD reported greater experience of calmness, clear-headedness, coordination and were more likely to report side-effects of dry mouth relative to placebo (all p < 0.05).

CONCLUSIONS

Relative to placebo, daytime cognitive functioning following nightly supplementation as a therapeutic aid for primary insomnia was preserved under trial conditions. Results suggested an overall favourable safety profile, with larger controlled trials and thorough analyses of varying insomnia phenotypes necessary to corroborate these findings.

Cannabidiol Reduces Nicotine Withdrawal Severity and State Anxiety During an Acute E-cigarette Abstinence Period: A Novel, Open-Label Study

Introduction: Despite efforts to curb nicotine use, 8.1 million adults in the United States use e-cigarettes. Notably, the majority of nicotine-containing e-cigarette users report wanting to quit in the near future, yet there is a dearth of research surrounding intervention efforts. Cannabidiol (CBD) has potential to facilitate e-cigarette quit attempts by decreasing withdrawal symptom intensity and anxiety during nicotine e-cigarette abstinence. Methods: This study employed an open-label, crossover design (n=20) to test the hypothesis that among daily nicotine-containing e-cigarette users, oral administration of 320 mg CBD would reduce self-reported nicotine withdrawal severity and state anxiety following a 4-h e-cigarette abstinence period compared to withdrawal and anxiety reported after abstinence in the absence of CBD. Results: After controlling for participants' positive CBD expectancies, results were consistent with hypotheses, suggesting CBD reduced both nicotine withdrawal symptom severity and state anxiety during e-cigarette abstinence. Conclusion: These preliminary findings suggest testing the impact of CBD on e-cigarette cessation attempts is warranted.

Cannabidiol: Pharmacodynamics and pharmacokinetic in the context of neuropsychiatric disorders

In this chapter we explored the growing interest in cannabinoids, particularly cannabidiol (CBD), over the last two decades due to their potential therapeutic applications in neurodegenerative and psychiatric disorders. CBD, a major non-psychotomimetic compound derived from Cannabis sativa, is highlighted as a safer alternative to other cannabinoids like Δ9-tetrahydrocannabinol (THC). Clinical trials have been investigating CBD formulations for conditions such as schizophrenia, multiple sclerosis, Alzheimer's, Parkinson's diseases, and stress-related disorders. However, limited access to CBD-approved formulations primarily due to their high-cost and concerns about the quality of market-available products, challenges regulatory agencies globally. The pharmacokinetics of CBD, especially after oral administration, present challenges with erratic absorption and low bioavailability. CBD's "promiscuous" pharmacodynamics involve interactions with various targets beyond the endocannabinoid system, complicating precise dosing in therapeutic interventions. This chapter delves into CBD's dose-response curves, revealing complexities that pose challenges in clinical practice. Nanobiotechnology emerges as a promising solution, with recent developments showing improved bioavailability, stability, and reduced toxicity through nanoencapsulation of CBD. While this phytocannabinoid holds immense promise in neuropsychopharmacology, we provided a comprehensive overview of the current state of CBD research and suggests potential future directions regarding the pharmacology of CBD, harnessing the benefits of this intriguing compound.

Cannabidiol in anxiety disorders: Current and future perspectives

Anxiety disorders are highly prevalent psychiatric disorders, characterized by a chronic course and often accompanied by comorbid symptoms that impair functionality and decrease quality of life. Despite advances in basic and clinical research in our understanding of these disorders, currently available pharmacological options are associated with limited clinical benefits and side effects that frequently lead to treatment discontinuation. Importantly, a significant number of patients do not achieve remission and live with lifelong residual symptoms that limit daily functioning. Since the 1970s, basic and clinical research on cannabidiol (CBD), a non-psychotomimetic compound found in the Cannabis sativa plant, has indicated relevant anxiolytic effects, garnering attention for its therapeutic potential as an option in anxiety disorder treatment. This chapter aims to review the history of these studies on the anxiolytic effects of CBD within the current understanding of anxiety disorders. It highlights the most compelling current evidence supporting its anxiolytic effects and explores future perspectives for its clinical use in anxiety disorders.

Cannabidiol (CBD) Products: Use Patterns and Perceptions Within a Sample of Anxious Users

INTRODUCTION

Cannabidiol (CBD) shows promise for a variety of indications, including anxiety. Prior survey work indicates anxiety ranks as a top reason for which people use cannabidiol (CBD), but no work has evaluated individuals using CBD specifically for anxiety.

METHOD

The current study evaluated CBD product use patterns and perceptions within a sample of 81 participants (Mage = 32.63, SDage = 12.99) who reported using CBD products for anxiety-related concerns within the past 30 days.

RESULTS

Family and friends, followed by popular and scientific literature, were the most common sources informing participants' decision to use CBD products to target anxiety. On average, participants reported using CBD products daily for at least a year and indicated it was very effective in targeting anxiety-related symptoms. The top three ranked symptoms improved by CBD products were subjective anxiety, difficulty falling asleep, and irritability. These findings were despite the fact that the most frequent dosing levels (∼50mg) were well below those empirically observed to yield anxiolytic effects. Most participants denied side effects, adding to the literature supporting CBD products' safety and tolerability. Finally, participants were generally poorly informed about the nature of CBD products (e.g., distinction from THC), suggesting a need for consumer education.

CONCLUSION

Collectively, the current study extends prior survey work suggesting powerful expectancies about CBD products, particularly in terms of anxiety reduction, including among those using it to target anxiety-related symptoms. Findings also highlight the importance of addressing the gap between scientific and consumer knowledge.

Interactions between metabotropic glutamate and CB1 receptors: implications for mood, cognition, and synaptic signaling based on data from mGluR and CB1R-targeting drugs

Metabotropic glutamate receptors (mGluRs) are part of the G protein-coupled receptors (GPCRs) family. They are coupled to Gαq (group I) or Gi/o (groups II and III) proteins, which result in the generation of diacylglycerol (DAG) and inositol 1,4,5-triphosphate (IP3) or the inhibition of adenylyl cyclase, respectively. mGluRs have been implicated in anxiety, depression, learning, and synaptic plasticity. Similarly, CB1 cannabinoid receptors (CB1Rs), also GPCRs, play roles in cognitive function and mood regulation through Gαi/o-mediated inhibition of adenylyl cyclase. Both mGluRs and CB1Rs exhibit surface labeling and undergo endocytosis. Given the similar cellular distribution and mechanisms of action, this review complies with fundamental data on the potential interactions and mutual regulation of mGluRs and CB1Rs in the context of depression, anxiety, and cognition, providing pioneering insights into their interplay.

An open-label feasibility trial of transdermal cannabidiol for hand osteoarthritis

Hand osteoarthritis (OA) is an irreversible degenerative condition causing chronic pain and impaired functionality. Existing treatment options are often inadequate. Cannabidiol (CBD) has demonstrated analgesic and anti-inflammatory effects in preclinical models of arthritis. In this open-label feasibility trial, participants with symptomatically active hand OA applied a novel transdermal CBD gel (4% w/w) three times a day for four weeks to their most painful hand. Changes in daily self-reported pain scores were measured on a 0-10 Numeric Pain Rating Scale (NPRS). Hand functionality was determined via daily grip strength measures using a Bluetooth equipped squeeze ball and self-report questionnaire. Quality of life (QoL) ratings around sleep, anxiety, stiffness and fatigue were also measured. All self-report measures and grip strength data were gathered via smartphone application. Urinalysis was conducted at trial end to determine systemic absorption of CBD. Eighteen participants were consented and 15 completed the trial. Pain ratings were significantly reduced over time from pre-treatment baseline including current pain (- 1.91 ± 0.35, p < 0.0001), average pain (- 1.92 ± 0.35, p < 0.0001) and maximum pain (- 1.97 ± 0.34, p < 0.0001) (data represent mean reduction on a 0-10 NPRS scale ± standard error of the mean (SEM)). A significant increase in grip strength in the treated hand (p < 0.0001) was observed although self-reported functionality did not improve. There were significant (p < 0.005) improvements in three QoL measures: fatigue, stiffness and anxiety. CBD and its metabolites were detected at low concentrations in all urine samples. Measured reductions in pain and increases in grip strength seen during treatment reverted back towards baseline during the washout phase. In summary, pain, grip strength and QoL measures, using smartphone technology, was shown to improve over time following transdermal CBD application suggesting feasibility of this intervention in relieving osteoarthritic hand pain. Proof of efficacy, however, requires further confirmation in a placebo-controlled randomised trial.Trial registration: ANZCTR public trials registry (ACTRN12621001512819, 05/11/2021).

The Effect of Cannabidiol on Subjective Responses to Endurance Exercise: A Randomised Controlled Trial

BACKGROUND

Exercise is known to improve health. However, it can be unpleasant, often inducing negative feelings, or 'affect'. Cannabidiol (CBD), a non-intoxicating constituent of the cannabis plant, has been reported to enhance the subjective experience of exercise; specifically, in trained individuals performing fixed-intensity endurance activity. Here, we investigated the effects of CBD on subjective responses to exercise under more ecologically valid conditions; namely, in recreationally active individuals performing self-paced endurance activity.

METHODS

A randomised, double-blind, placebo-controlled, crossover trial was conducted at Griffith University between July 17 and August 28, 2023. Griffith University students studying sports nutrition were invited to take part, with eligible volunteers ≥ 18 years of age and able to perform endurance exercise. Participants ingested placebo or 150 mg CBD in two soft-gel capsules 90 min before completing a self-paced 25-lap (10 km) run around an outdoor athletics track (400 m, synthetic). The primary outcomes were affective valence during exercise, assessed on completion of laps 6, 12, 18 and 24 using the 'Feelings Scale', and positive and negative affect, assessed at baseline, pre-run and post-run using the 'Positive and Negative Affect Schedule'. Exercise enjoyment, motivation and self-efficacy, the core features of the 'runner's high' (i.e., euphoria, pain, anxiety, sedation), perceived exertion and run time were also assessed.

RESULTS

Fifty-two participants were randomised and 51 were included in the final sample (n = 22 female; 22 [21-25] years). Exercise induced negative affect (i.e., at the time of undertaking) and increased pain. CBD did not counteract either response. In fact, CBD had no significant effects on any of the outcomes measured. In contrast, exercise, once completed, increased positive affect, and decreased negative affect and anxiety.

CONCLUSIONS

CBD (150 mg, oral) does not appear to enhance the subjective experience of self-paced endurance exercise in recreationally active individuals. Nor, however, does it appear to compromise it. These findings suggest that CBD use is safe under exercise conditions and unlikely to impede physical activity participation. Our study also reaffirms the powerful mood-enhancing effects of exercise.

TRIAL REGISTRATION

Registered with the Australian New Zealand Clinical Trials Registry ( www.anzctr.org.au ) on May 31, 2023 (Trial ID: ACTRN12623000593639).

Biphasic effects of cannabis and cannabinoid therapy on pain severity, anxiety, and sleep disturbance: a scoping review

INTRODUCTION

Cannabinoids are being used by patients to help with chronic pain management and to address the 2 primary chronic pain comorbidities of anxiety and sleep disturbance. It is necessary to understand the biphasic effects of cannabinoids to improve treatment of this symptom triad.

METHODS

A scoping review was conducted to identify whether biphasic effects of cannabinoids on pain severity, anxiolysis, and sleep disturbance have been reported. The search included the Embase, Biosis, and Medline databases of clinical literature published between 1970 and 2021. The inclusion criteria were (1) adults more than 18 years of age, (2) data or discussion of dose effects associated with U-shaped or linear dose responses, and (3) measurements of pain and/or anxiety and/or sleep disturbance. Data were extracted by 2 independent reviewers (with a third reviewer used as a tiebreaker) and subjected to a thematic analysis.

RESULTS

After the database search and study eligibility assessment, 44 publications met the final criteria for review. Eighteen publications that specifically provided information on dose response were included in the final synthesis: 9 related to pain outcomes, 7 measuring anxiety, and 2 reporting sleep effects.

CONCLUSIONS

This scoping review reports on biphasic effects of cannabinoids related to pain, sleep, and anxiety. Dose-response relationships are present, but we found gaps in the current literature with regard to biphasic effects of cannabinoids in humans. There is a lack of prospective research in humans exploring this specific relationship.

Cannabidiol for moderate-severe insomnia: a randomized controlled pilot trial of 150 mg of nightly dosing

STUDY OBJECTIVES

Low-dose cannabidiol (CBD) has become readily available in numerous countries; however, little consensus exists on its efficacy as a sleep aid. This trial explored the efficacy of 150 mg of CBD (n = 15) compared with placebo (n = 15) as a sleep aid in primary insomnia. CBD supplementation was hypothesized to decrease insomnia symptoms and improve aspects of psychological health, relative to placebo.

METHODS

Using a randomized, placebo-controlled, parallel design featuring a single-blind placebo run-in week followed by a 2-week double-blind randomized dosing phase, participants consumed the assigned treatment sublingually 60 minutes before bed nightly. Wrist-actigraphy and sleep diaries measured daily sleep. Sleep quality, sleep effort, and well-being were measured weekly over 4 in-laboratory visits. Insomnia severity and trait anxiety were measured at screening and study conclusion.

RESULTS

Insomnia severity, self-reported sleep-onset latency, sleep efficiency, and wake after sleep onset did not differ between treatments throughout the trial (all P > .05). Compared with placebo, the CBD group reported greater well-being scores throughout the trial (trial end mean difference = 2.60; standard error: 1.20), transient elevated behavior following wakefulness scores after 1 week of treatment (mean difference = 3.93; standard error: 1.53), and had superior objective sleep efficiency after 2 weeks of treatment (mean difference = 6.85; standard error: 2.95) (all P < .05). No other significant treatment effects were observed.

CONCLUSIONS

Nightly supplementation of 150 mg CBD was similar to placebo regarding most sleep outcomes while sustaining greater well-being, suggesting more prominent psychological effects. Additional controlled trials examining varying treatment periods and doses are crucial.

CLINICAL TRIAL REGISTRATION

Registry: Australian New Zealand Clinical Trials Registry; Name: Cannabidiol (CBD) treatment for insomnia; URL: https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12620000070932; Identifier: ACTRN12620000070932.

CITATION

Narayan AJ, Downey LA, Rose S, Di Natale L, Hayley AC. Cannabidiol for moderate-severe insomnia: a randomized controlled pilot trial of 150 mg of nightly dosing. J Clin Sleep Med. 2024;20(5):753-763.

Perceptions, Experiences, and Patterns of Cannabis Use in Individuals with Mood and Anxiety Disorders in the Context of Cannabis Legalization and Medical Cannabis Program in Canada - A Qualitative Study

INTRODUCTION

Perceptions of cannabis as a potential medical treatment for mood and anxiety disorders have been increasing in the context of legalizations, availability, and medical cannabis programs, though current evidence predominately indicates risks and negative effects of cannabis use (CU) on mental health outcomes. This study aims to understand motivations, perceptions, effects, and patterns of CU in individuals with mood and anxiety disorders.

METHODS

Thirty-six adult patients diagnosed with mood or anxiety disorders, obsessive-compulsive disorder, or posttraumatic stress disorder who were currently using cannabis completed an in-depth qualitative interview on individual motivations, perceptions, experiences, effects, and patterns of their CU. The thematic analysis focused on phases of CU and sources of cannabis products and information.

RESULTS

Reported motivations for initiation of CU included curiosity, peer pressure, and dissatisfaction with conventional treatments. Factors such as psychotropic effects and coping with mental health symptoms and insomnia contributed to the continuation of CU. More negative effects, including cognitive dysfunction, worsening of mood, and anxiety symptoms, were acknowledged with ongoing CU. Concerning findings included common initiation of CU before age 18, combined medical and recreational CU, rare consultation of medical professionals on CU, and potential effects and harms.

DISCUSSION

Findings indicate individual complexity of motivations, perceptions, and patterns of CU in the study population. The reported potential beneficial effects of specific cannabis products should be further investigated. Findings emphasize patient-provider dialogue on both CU and conventional treatments. Information from this study can contribute to and inform the development of education, prevention, and intervention strategies.

Should Cannabis be Used for Anorexia in Patients With Cancer?

Healthcare professionals are frequently asked about the benefits of cannabis for appetite or anorexia-cachexia syndrome. In popular culture, cannabis has a reputation of causing an increased hunger, slang termed "the munchies," so many patients consume this with the hope that it may improve the loss of appetite associated with serious illness such as cancer. There have only been a few randomized, controlled trials studying the controversial question as to if cannabis improves appetite. These studies are small and show no statistically significant benefit for appetite and one small study showed improvement of taste for foods. Due to regulation barriers, the studies have use synthetic products, not the products that represent what is more commonly used in the population, often whole flower smoked, vaporized or oral products. Despite the popularity of cannabis in culture, often touted as a panacea for all maladies, the evidence and education for several adverse effects and potential drug interactions have has yet to catch up with the cultural craze. International cannabis experts in the United States and Australia do not routinely certify patients for medical cannabis off trial for anorexia-cachexia, but one expert in Canada would consider use in selected cancer patients.

Cannabinoids in the Treatment of Selected Mental Illnesses: Practical Approach and Overview of the Literature

Although an increasing number of patients suffering from mental illnesses self-medicate with cannabis, current knowledge about the efficacy and safety of cannabis-based medicine in psychiatry is still extremely limited. So far, no cannabis-based finished product has been approved for the treatment of a mental illness. There is increasing evidence that cannabinoids may improve symptoms in autism spectrum disorder (ASD), Tourette syndrome (TS), anxiety disorders, and post-traumatic stress disorder (PTSD). According to surveys, patients often use cannabinoids to improve mood, sleep, and symptoms of attention deficit/hyperactivity disorder (ADHD). There is evidence suggesting that tetrahydrocannabinol (THC) and THC-containing cannabis extracts, such as nabiximols, can be used as substitutes in patients with cannabis use disorder.Preliminary evidence also suggests an involvement of the endocannabinoid system (ECS) in the pathophysiology of TS, ADHD, and PTSD. Since the ECS is the most important neuromodulatory system in the brain, it possibly induces beneficial effects of cannabinoids by alterations in other neurotransmitter systems. Finally, the ECS is an important stress management system. Thus, cannabinoids may improve symptoms in patients with mental illnesses by reducing stress.Practically, cannabis-based treatment in patients with psychiatric disorders does not differ from other indications. The starting dose of THC-containing products should be low (1-2.5 mg THC/day), and the dose should be up-titrated slowly (by 1-2.5 mg every 3-5 days). The average daily dose is 10-20 mg THC. In contrast, cannabidiol (CBD) is mainly used in high doses>400 mg/day.

Cannabidiol and its Potential Evidence-Based Psychiatric Benefits - A Critical Review

The endocannabinoid system shows promise as a novel target for treating psychiatric conditions. Cannabidiol (CBD), a naturally occurring cannabinoid, has been investigated in several psychiatric conditions, with diverse effects and an excellent safety profile compared to standard treatments. Even though the body of evidence from randomised clinical trials is growing, it remains relatively limited in most indications. This review comprises a comprehensive literature search to identify clinical studies on the effects of CBD in psychiatric conditions. The literature search included case studies, case reports, observational studies, and RCTs published in English before July 27, 2023, excluding studies involving nabiximols or cannabis extracts containing CBD and ∆9-tetrahydrocannabinol. Completed studies were considered, and all authors independently assessed relevant publications.Of the 150 articles identified, 54 publications were included, covering the effects of CBD on healthy subjects and various psychiatric conditions, such as schizophrenia, substance use disorders (SUDs), anxiety, post-traumatic stress disorder (PTSD), and autism spectrum disorders. No clinical studies have been published for other potential indications, such as alcohol use disorder, borderline personality disorder, depression, dementia, and attention-deficit/hyperactivity disorder. This critical review highlights that CBD can potentially ameliorate certain psychiatric conditions, including schizophrenia, SUDs, and PTSD. However, more controlled studies and clinical trials, particularly investigating the mid- to long-term use of CBD, are required to conclusively establish its efficacy and safety in treating these conditions. The complex effects of CBD on neural activity patterns, likely by impacting the endocannabinoid system, warrant further research to reveal its therapeutic potential in psychiatry.

Effects of cannabidiol on psychosocial stress, situational anxiety and nausea in a virtual reality environment: a protocol for a single-centre randomised clinical trial

INTRODUCTION

The non-intoxicating plant-derived cannabinoid, cannabidiol (CBD), has demonstrated therapeutic potential in a number of clinical conditions. Most successful clinical trials have used relatively high (≥300 mg) oral doses of CBD. Relatively few studies have investigated the efficacy of lower (<300 mg) oral doses, typical of those available in over-the-counter CBD products.

METHODS

We present a protocol for a randomised, double-blind, placebo-controlled, parallel-group clinical trial investigating the effects of a low oral dose (150 mg) of CBD on acute psychosocial stress, situational anxiety, motion sickness and cybersickness in healthy individuals. Participants (n=74) will receive 150 mg of CBD or a matched placebo 90 min before completing three virtual reality (VR) challenges (tasks) designed to induce transient stress and motion sickness: (a) a 15 min 'Public Speaking' task; (b) a 5 min 'Walk the Plank' task (above a sheer drop); and (c) a 5 min 'Rollercoaster Ride' task. The primary outcomes will be self-reported stress and nausea measured on 100 mm Visual Analogue Scales. Secondary outcomes will include salivary cortisol concentrations, skin conductance, heart rate and vomiting episodes (if any). Statistical analyses will test the hypothesis that CBD reduces nausea and attenuates subjective, endocrine and physiological responses to stress compared with placebo. This study will indicate whether low-dose oral CBD has positive effects in reducing acute psychosocial stress, situational anxiety, motion sickness and cybersickness.

ETHICS AND DISSEMINATION

The University of Sydney Human Research Ethics Committee has granted approval (2023/307, version 1.6, 16 February 2024). Study findings will be disseminated in a peer-reviewed journal and at academic conferences.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12623000872639).

A narrative review of the therapeutic and remedial prospects of cannabidiol with emphasis on neurological and neuropsychiatric disorders

BACKGROUND

The treatment of diverse diseases using plant-derived products is actively encouraged. In the past few years, cannabidiol (CBD) has emerged as a potent cannabis-derived drug capable of managing various debilitating neurological infections, diseases, and their associated complications. CBD has demonstrated anti-inflammatory and curative effects in neuropathological conditions, and it exhibits therapeutic, apoptotic, anxiolytic, and neuroprotective properties. However, more information on the reactions and ability of CBD to alleviate brain-related disorders and the neuroinflammation that accompanies them is needed.

MAIN BODY

This narrative review deliberates on the therapeutic and remedial prospects of CBD with an emphasis on neurological and neuropsychiatric disorders. An extensive literature search followed several scoping searches on available online databases such as PubMed, Web of Science, and Scopus with the main keywords: CBD, pro-inflammatory cytokines, and cannabinoids. After a purposive screening of the retrieved papers, 170 (41%) of the articles (published in English) aligned with the objective of this study and retained for inclusion.

CONCLUSION

CBD is an antagonist against pro-inflammatory cytokines and the cytokine storm associated with neurological infections/disorders. CBD regulates adenosine/oxidative stress and aids the downregulation of TNF-α, restoration of BDNF mRNA expression, and recovery of serotonin levels. Thus, CBD is involved in immune suppression and anti-inflammation. Understanding the metabolites associated with response to CBD is imperative to understand the phenotype. We propose that metabolomics will be the next scientific frontier that will reveal novel information on CBD's therapeutic tendencies in neurological/neuropsychiatric disorders.

Self-reported knowledge of tetrahydrocannabinol and cannabidiol concentration in cannabis products among cancer patients and survivors

PURPOSE

Cannabis use may introduce risks and/or benefits among people living with cancer, depending on product type, composition, and nature of its use. Patient knowledge of tetrahydrocannabinol (THC) or cannabidiol (CBD) concentration could provide information for providers about cannabis use during and after treatment that may aide in risk and benefit assessments. This study aimed to examine knowledge of THC or CBD concentration among patients living with cancer who consume cannabis, and factors associated with knowledge of cannabinoid concentrations.

METHODS

People living with cancer who consumed cannabis since their diagnosis (n = 343) completed an anonymous, mixed-mode survey. Questions assessed usual mode of delivery (MOD), knowledge of THC/CBD concentration, and how source of acquisition, current cannabis use, and source of instruction are associated with knowledge of THC/CBD concentration. Chi-square and separate binary logistic regression analyses were examined and weighted to reflect the Roswell Park patient population.

RESULTS

Less than 20% of people living with cancer had knowledge of THC and CBD concentration for the cannabis products they consumed across all MOD (smoking- combustible products, vaping- vaporized products (e-cigarettes), edibles-eating or drinking it, and oral- taking by mouth (pills)). Source of acquisition (smoking-AOR:4.6, p < 0.01, vaping-AOR:5.8, p < 0.00, edibles-AOR:2.6, p < 0.04), current cannabis use (edibles-AOR:5.4, p < 0.01, vaping-AOR: 11.2, p < 0.00, and oral-AOR:9.3, p < 0.00), and source of instruction (vaping only AOR:4.2, p < 0.05) were found to be variables associated with higher knowledge of THC concentration.

CONCLUSION

Self-reported knowledge of THC and CBD concentration statistically differed according to MOD, source of acquisition, source of instruction, and current cannabis use.

Cannabidiol usage, efficacy, and side effects: analyzing the impact of health conditions, medications, and cannabis use in a cross-sectional online pilot study

Background

Products containing cannabidiol (CBD) are attracting attention because of their potential therapeutic benefits and positive impacts on well-being and mental health. Although additional research is needed to understand their effectiveness in treating mental disorders, cross-sectional studies may help identify the factors influencing CBD use patterns. This study examined the impact of variables such as health status, medication use, medical supervision, gender, age, and cannabis use on CBD consumption patterns.

Materials and methods

A self-selected sample (n =267) of current or former CBD users was recruited via social media and participated in an online survey designed to collect data on basic demographics, health status, cannabis use, and CBD usage patterns.

Results

The sample (n = 267) consisted of 68.5% women with an average age of 30.21 years, of which 25.8% reported diagnosed psychiatric disorders and 49.4% reported cannabis use. The top five reasons for using CBD were self-reported stress (65.3%), sleep problems (51.7%), overall improvement in well-being (52.5%), improved mood (44.9%), and anxiety relief (40.9%). Our findings suggest that individuals with psychiatric disorders and those taking psychotropic medications are more likely to use CBD to relieve stress and anxiety. Overall, nearly 70% of the individuals found CBD products to be effective. Sublingual administration was more popular among non-cannabis users, while cannabis users preferred smoking and vaping to CBD administration.

Conclusion

Our results indicate that individuals using CBD for health and wellness reasons believe that it has potential health benefits. Further research using rigorous longitudinal designs is needed to delve deeper into the effectiveness of low-dose CBD and to better understand the therapeutic potential of CBD.

Subjective, behavioral and neurobiological effects of cannabis and cannabinoids in social anxiety

Social anxiety disorder (SAD) is a debilitating disorder, characterized by fear and anxiety in social situations. Evidence suggests that the levels of SAD are rising, in particularly after the COVID-19 pandemic. Serotonin and noradrenaline reuptake inhibitors and cognitive-behavioral therapy are effective treatments for SAD. Nevertheless, a significant number of patients do not respond well to these therapeutic options. During the last years, Cannabis and cannabinoid-containing products have been investigated for the treatment of different neuropsychiatric disorders. Nevertheless, their efficacy for the treatment of anxiety disorders is still a matter of debate. The purpose of this review was to investigate subjective, behavioral, and neurobiological effects of Cannabis and cannabinoids in social anxiety and SAD. A search in the PubMed database for articles published between the years of 2003-2023 was conducted. One hundred and seventeen (117) original studies were identified. After the exclusion criteria, eighteen (18) studies were selected. The studies investigated the effects of the cannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in patients or healthy volunteers submitted to tasks that assessed social anxiety. Results showed that CBD decreases social anxiety, producing an inverted U-shaped curve, with anxiety measurements being reduced at intermediate doses administered orally (300-600 mg), but not at lower or higher doses. THC either reduces (lower doses, 6-7.5 mg) or increases (higher doses) social anxiety measurements. CBD attenuates the anxiogenic effects of THC. The effects of THC and CBD in anxiety are associated to the modulation of fronto-limbic regions. Further clinical trials, conducted with male and female patients and larger cohorts are still necessary to consolidate these results.

Effect of MCH1, a fatty-acid amide hydrolase inhibitor, on the depressive-like behavior and gene expression of endocannabinoid and dopaminergic-signaling system in the mouse nucleus accumbens

MCH1 is a synthetic macamide that has shown in vitro inhibitory activity on fatty acid amide hydrolase (FAAH), an enzyme responsible for endocannabinoid metabolism. This inhibition can modulate endocannabinoid and dopamine signaling in the nucleus accumbens (NAc), potentially having an antidepressant-like effect. The present study aimed to evaluate the effect of the in vivo administration of MCH1 (3, 10, and 30 mg/kg, ip) in 2-month-old BALB/c male mice (n=97) on forced swimming test (FST), light-dark box (LDB), and open field test (OFT) and on early gene expression changes 2 h after drug injection related to the endocannabinoid system (Cnr1 and Faah) and dopaminergic signaling (Drd1 and Drd2) in the NAc core. We found that the 10 mg/kg MCH1 dose reduced the immobility time compared to the vehicle group in the FST with no effect on anxiety-like behaviors measured in the LDB or OFT. However, a 10 mg/kg MCH1 dose increased locomotor activity in the OFT compared to the vehicle. Moreover, RT-qPCR results showed that the 30 mg/kg MCH1 dose increased Faah gene expression by 2.8-fold, and 10 mg/kg MCH1 increased the Cnr1 gene expression by 4.3-fold compared to the vehicle. No changes were observed in the expression of the Drd1 and Drd2 genes in the NAc at either MCH1 dose. These results indicated that MCH1 might have an antidepressant-like effect without an anxiogenic effect and induces significant changes in endocannabinoid-related genes but not in genes of the dopaminergic signaling system in the NAc of mice.

Discriminative-stimulus effects of cannabidiol oil in Sprague-Dawley rats

Cannabidiol (CBD) is one of the major centrally active phytocannabinoid components of cannabis, and has been approved by the FDA only for the treatment of seizures associated with three rare disorders. It has also been touted as a potential treatment for anxiety in place of more traditional treatments like benzodiazepines. Although there is some evidence of anxiolytic effects of CBD, its suitability as a substitute for benzodiazepines is unknown. This experiment was designed to assess the extent to which CBD shares interoceptive discriminative-stimulus properties with the anxiolytic drug chlordiazepoxide (CDP), a benzodiazepine. In the present experiment, a range of doses (0-1569 mg/kg) of over-the-counter CBD oil was administered (i.g.) in male Sprague-Dawley rats trained to discriminate 5.6 mg/kg CDP from saline. Due to the long time-course effects of CBD, generalization tests were conducted at 90 and 120 min post-CBD administration. The two highest doses of CBD tested (1064 and 1569 mg/kg) were found to partially substitute for 5.6 mg/kg CDP, with mean percent responding on the CDP-associated lever reaching above 20% at time 2 (120 min post-CBD administration), suggesting that high doses of the over-the-counter CBD oils used in this experiment share interoceptive discriminative-stimulus properties to some degree with CDP. These results are novel in comparison to existing research into stimulus effects of CBD, in which substitution for benzodiazepines has not previously been observed.

Cannabinoid Exposure and Subjective Effects of THC and CBD in Edible Cannabis Products

Background: The popularity of edible cannabis products continues to grow in states with legal cannabis access, but few studies have investigated the acute effects of these commercially available products. The present study sought to explore the effects of three commercially available edible products with different levels of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Methods: A sample of regular cannabis users (N=99) were evaluated. Fifty participants completed the study procedures in-person, whereas 49 participants completed the study procedures remotely via Zoom. Subjective effects and plasma cannabinoid levels (in-person participants only) were assessed before and 2 h after participants self-administered one of three products ad libitum: a THC-dominant edible product, a CBD-dominant edible product, or a THC+CBD edible product. Results: At the 2-h post-use assessment, among in-person participants, plasma THC and CBD levels were robustly correlated with self-reported milligrams of THC and CBD consumed, respectively. Across all three conditions, in-person and remote participants experienced (1) an increase in subjective intoxication and elation, (2) a decrease in tension, and (3) no change in paranoia from pre-use to post-use. At post-use, participants who used a CBD product reported less intoxication relative to participants who used a THC+CBD or THC-only product. Participants who used a THC+CBD product reported consuming less THC-and displayed lower plasma THC levels (in-person participants)-relative to participants who used a THC-only product, despite reporting similar levels of positive (intoxication, elation, liking) and psychotomimetic (paranoia, tension) effects. Psychotomimetic effects were very low among both in-person and remote participants across all three conditions, and there were no post-use differences across conditions. Conclusions: Findings suggest that experienced users who consumed a THC+CBD product reported similar levels of positive and psychotomimetic effects relative to those who consumed a THC-only product, despite consuming less THC and displaying lower plasma THC concentrations. Given the potential harms associated with acute cannabis reward and long-term THC exposure, further research is needed to establish whether edible cannabis products with CBD pose less risk to users. Future studies should examine whether these effects generalize to samples of infrequent users, who may have less experience with edible cannabis use. ClinicalTrials.gov ID: NCT03522103.

Cannabidiol and brain function: current knowledge and future perspectives

Cannabidiol (CBD) is a naturally occurring non-psychoactive cannabinoid found in Cannabis sativa, commonly known as cannabis or hemp. Although currently available CBD products do not meet the safety standards of most food safety authorities to be approved as a dietary supplement or food additive, CBD has been gaining widespread attention in recent years due to its various potential health benefits. While primarily known for its therapeutic effects in managing epileptic seizures, psychosis, anxiety, (neuropathic) pain, and inflammation, CBD's influence on brain function has also piqued the interest of researchers and individuals seeking to enhance cognitive performance. The primary objective of this review is to gather, synthesize, and consolidate scientifically proven evidence on the impact of CBD on brain function and its therapeutic significance in treating neurological and mental disorders. First, basic background information on CBD, including its biomolecular properties and mechanisms of action is presented. Next, evidence for CBD effects in the human brain is provided followed by a discussion on the potential implications of CBD as a neurotherapeutic agent. The potential effectiveness of CBD in reducing chronic pain is considered but also in reducing the symptoms of various brain disorders such as epilepsy, Alzheimer's, Huntington's and Parkinson's disease. Additionally, the implications of using CBD to manage psychiatric conditions such as psychosis, anxiety and fear, depression, and substance use disorders are explored. An overview of the beneficial effects of CBD on aspects of human behavior, such as sleep, motor control, cognition and memory, is then provided. As CBD products remain largely unregulated, it is crucial to address the ethical concerns associated with their use, including product quality, consistency, and safety. Therefore, this review discusses the need for responsible research and regulation of CBD to ensure its safety and efficacy as a therapeutic agent for brain disorders or to stimulate behavioral and cognitive abilities of healthy individuals.

The Safety and Comparative Effectiveness of Non-Psychoactive Cannabinoid Formulations for the Improvement of Sleep: A Double-Blinded, Randomized Controlled Trial

BACKGROUND

Clinical evidence on the use of cannabidiol (CBD) for sleep remains limited. Even fewer studies have tested the comparative effectiveness of cannabinoid formulations found within CBD products used for sleep or how they compare to other complementary therapies such as melatonin.

METHODS

Participants (N = 1,793 adults experiencing symptoms of sleep disturbance) were randomly assigned to receive a 4-week supply of 1 of 6 products (all capsules) containing either 15 mg CBD or 5 mg melatonin, alone or in combination with minor cannabinoids. Sleep disturbance was assessed over a period of 5 weeks (baseline week and 4 weeks of product use) using Patient-Reported Outcomes Measurement Information System (PROMIS™) Sleep Disturbance SF 8A, administered via weekly online surveys. A linear mixed-effects regression model was used to assess the differences in the change in sleep disturbance through time between each active product arm and CBD isolate.

RESULTS

All formulations exhibited a favorable safety profile (12% of participants reported a side effect and none were severe) and led to significant improvements in sleep disturbance (p < 0.001 in within-group comparisons). Most participants (56% to 75%) across all formulations experienced a clinically important improvement in their sleep quality. There were no significant differences in effect, however, between 15 mg CBD isolate and formulations containing 15 mg CBD and 15 mg cannabinol (CBN), alone or in combination with 5 mg cannabichromene (CBC). There were also no significant differences in effect between 15 mg CBD isolate and formulations containing 5 mg melatonin, alone or in combination with 15 mg CBD and 15 mg CBN.

CONCLUSIONS

Our findings suggest that chronic use of a low dose of CBD is safe and could improve sleep quality, though these effects do not exceed that of 5 mg melatonin. Moreover, the addition of low doses of CBN and CBC may not improve the effect of formulations containing CBD or melatonin isolate.

Relationship Between Nociplastic Pain Involvement and Medication Use, Symptom Relief, and Adverse Effects Among People Using Medical Cannabis for Chronic Pain

OBJECTIVES

Cannabis is increasingly being used for chronic pain management, but cannabis' effects remain poorly characterized in chronic nociplastic pain (NPP), which is posited to be caused by disturbances in nervous system pain processing. In this cross-sectional study (n=1213), we used the 2011 Fibromyalgia (FM) Survey Criteria as a surrogate measure for degree of NPP among individuals using medical cannabis for chronic pain.

METHODS

Using a quartile-split, we investigated associations between the degree of NPP and medication use, cannabis use characteristics, and symptom relief. Continuous variables were assessed using one-way analysis of variance and categorical variables with Pearson χ 2 test and binomial logistic regression for calculation of odds ratios.

RESULTS

Participants were predominately female (59%), with a mean ± SD age of 49.4±13.6 years. Higher FM scores were associated with less self-reported improvement in pain and health since initiating medical cannabis use, as well as more cannabis-related side effects. Paradoxically, higher FM scores were also associated with higher usage of concomitant medication use (including opioids and benzodiazepines) but also with substituting cannabis for significantly more medication classes, including opioids and benzodiazepines.

DISCUSSION

This article presents evidence that individuals in higher NPP quartiles have higher analgesic intake, higher odds of substituting cannabis for medications, higher side effect burden, and lower therapeutic effect from cannabis. These seemingly contradictory findings may reflect higher symptom burden, polypharmacy at baseline, or that NPP may be challenging to treat with cannabis. Further research is necessary to further explain cannabinoid effects in NPP.

Thoughtfully Integrating Cannabis Products Into Chronic Pain Treatment

Cannabis products (CPs) and cannabis-based medicines (CBMs) are becoming increasingly available and are commonly used for pain management. The growing societal acceptance of cannabis and liberalization of cannabis laws allows patients to access CPs with minimal clinical oversight. While there is mechanistic plausibility that CPs and CBMs may be useful for pain management, the clinical trial literature is limited and does not refute or support the use of CBMs for pain management. Complicating matters, a large and growing body of observational literature shows that many people use CPs for pain management and in place of other medications. However, products and dosing regimens in existing trials are not generalizable to the current cannabis market, making it difficult to compare and reconcile these 2 bodies of literature. Given this complexity, clinicians need clear, pragmatic guidance on how to appropriately educate and work with patients who are using CBMs for pain management. In this review, we narratively synthesize the evidence to enable a clear view of current landscape and provide pragmatic advice for clinicians to use when working with patients. This advice revolves around 3 principles: (1) maintaining the therapeutic alliance; (2) harm reduction and benefit maximization; and (3) pragmatism, principles of patient-centered care, and use of best clinical judgment in the face of uncertainty. Despite the lack of certainty CPs and chronic pain management use, we believe that following these principles can make most of the clinical opportunity presented by discussions around CPs and also enhance the likelihood of clinical benefit from CPs.

The psychedelic effects of cannabis: A review of the literature

Cannabis and classic psychedelics are controlled substances with emerging evidence of efficacy in the treatment of a variety of psychiatric illnesses. Cannabis has largely not been regarded as having psychedelic effects in contemporary literature, despite many examples of historical use along with classic psychedelics to attain altered states of consciousness. Research into the "psychedelic" effects of cannabis, and delta-9-tetrahydrocannabinol (THC) in particular, could prove helpful for assessing potential therapeutic indications and elucidating the mechanism of action of both cannabis and classic psychedelics. This review aggregates and evaluates the literature assessing the capacity of cannabis to yield the perceptual changes, aversiveness, and mystical experiences more typically associated with classic psychedelics such as psilocybin. This review also provides a brief contrast of neuroimaging findings associated with the acute effects of cannabis and psychedelics. The available evidence suggests that high-THC cannabis may be able to elicit psychedelic effects, but that these effects may not have been observed in recent controlled research studies due to the doses, set, and settings commonly used. Research is needed to investigate the effects of high doses of THC in the context utilized in therapeutic studies of psychedelics aimed to occasion psychedelic and/or therapeutic experiences. If cannabis can reliably generate psychedelic experiences under these conditions, high-THC dose cannabis treatments should be explored as potential adjunctive treatments for psychiatric disorders and be considered as an active comparator in clinical trials involving traditional psychedelic medications.

Cannabidiol Modifies the Glutamate Over-Release in Brain Tissue of Patients and Rats with Epilepsy: A Pilot Study

Drug-resistant epilepsy (DRE) is associated with high extracellular levels of glutamate. Studies support the idea that cannabidiol (CBD) decreases glutamate over-release. This study focused on investigating whether CBD reduces the evoked glutamate release in cortical synaptic terminals obtained from patients with DRE as well as in a preclinical model of epilepsy. Synaptic terminals (synaptosomes) were obtained from the epileptic neocortex of patients with drug-resistant temporal lobe epilepsy (DR-TLE, n = 10) or drug-resistant extratemporal lobe epilepsy (DR-ETLE, n = 10) submitted to epilepsy surgery. Synaptosomes highly purified by Percoll-sucrose density gradient were characterized by confocal microscopy and Western blot. Synaptosomes were used to estimate the high KCl (33 mM)-evoked glutamate release in the presence of CBD at different concentrations. Our results revealed responsive tissue obtained from seven patients with DR-TLE and seven patients with DR-ETLE. Responsive tissue showed lower glutamate release (p < 0.05) when incubated with CBD at low concentrations (less than 100 µM) but not at higher concentrations. Tissue that was non-responsive to CBD (DR-TLE, n = 3 and DR-ELTE, n = 3) showed high glutamate release despite CBD exposure at different concentrations. Simultaneously, a block of the human epileptic neocortex was used to determine its viability through whole-cell and extracellular electrophysiological recordings. The electrophysiological evaluations supported that the responsive and non-responsive human epileptic neocortices used in the present study exhibited proper neuronal viability and stability to acquire electrophysiological responses. We also investigated whether the subchronic administration of CBD could reduce glutamate over-release in a preclinical model of temporal lobe epilepsy. Administration of CBD (200 mg/kg, p.o. every 24 h for 7 days) to rats with lithium-pilocarpine-evoked spontaneous recurrent seizures reduced glutamate over-release in the hippocampus. The present study revealed that acute exposure to low concentrations of CBD can reduce the glutamate over-release in synaptic terminals obtained from some patients with DRE. This effect is also evident when applied subchronically in rats with spontaneous recurrent seizures. An important finding was the identification of a group of patients that were non-responsive to CBD effects. Future studies are essential to identify biomarkers of responsiveness to CBD to control DRE.

A Double-Blind, Randomized, Placebo-Controlled Test of the Effects of Cannabidiol on Experiences of Test Anxiety Among College Students

Introduction: Oral administration of cannabidiol (CBD) has shown to yield a variety of therapeutic benefits among humans, particularly regarding symptoms of anxiety. This study tested single oral administration doses of CBD (150, 300, or 600 mg), compared to placebo, for reducing test anxiety (TA) in a researcher-derived experimental analog. Method: Our sample included 32 healthy college students who self-reported moderate-to-severe levels of TA. Participants attended an experimental session, and received a dose of CBD or placebo, in a double-blind procedure. After administration of CBD, participants completed a statistics examination and measures of TA and general anxiety during examination administration. Results: Results indicated no effect of CBD dose on self-reported TA or general anxiety; however, results indicated efficacy of our experimental manipulation for inducing TA in vivo. Discussion: This is the first study to demonstrate that CBD does not reduce experiences of TA, and future work may examine the underlying mechanisms and affective states related to anxiety for which CBD may offer anxiolytic benefits, and for whom.

[Cannabis use in adolescents : Narrative Review and Position paper of the "Addiction Disorders in Adolescents" task force of the Austrian Society for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy (ÖGKJP)]

BACKGROUND

Cannabis is the illegal drug most frequently used by Minors in Austria. Due to the gradual decriminalization and legalization that has taken place in many European countries in recent years, the ÖGKJP would like to take a balanced and scientifically based stand on the complex issue of cannabis use and abuse among young people.

METHODS

The authors searched the medline for current studies using searches tailored to each specific subtopic. Furthermore, recognized compendiums were quoted.

RESULTS

While occasional recreational use of cannabis in adults with completed brain maturation and no risk profile for mental disorders is likely to be relatively harmless, early initiation of use with regular use and the increasingly available, highly potent cannabis varieties can lead to explicit and sometimes irreversible neurocognitive brain dysfunction.

CONCLUSION

Legalisation of cannabis consumption for minors needs to be objected to due to the risks of the expected damage in the area of brain development. At the same time, however, it is important to establish sensible legal regulations in order to be able to adequately counteract the fact that over 30% of all European young people occasionally consume cannabis. We are also clearly recommending to not criminalize cannabis users and provide necessary support to vulnerable and addicted cannabis users.

Effects of the Acute and Chronic Administration of Cannabidiol on Cognition in Humans and Animals: A Systematic Review

Introduction: The effects of cannabidiol (CBD) on cognition has been investigated in recent years to determine the therapeutic potential of this cannabinoid for a broad gamut of medical conditions, including neuropsychiatric disorders. The aim of the present study was to perform a systematic review of studies that analyzed the effects of the acute and chronic administration of CBD on cognition in humans and animals both to assess the cognitive safety of CBD and to determine a beneficial potential of CBD on cognition. Methods: The PubMed, Web of Science, PsycINFO, and Scopus databases were searched in December of 2022 for relevant articles using the following combinations of keywords: ("cannabidiol" OR "CBD") AND ("cognition" OR "processing cognitive" OR "memory" OR "language" OR "attention" OR "executive function" OR "social cognition" OR "perceptual motor ability" OR "processing speed"). Results: Fifty-nine articles were included in the present review (36 preclinical and 23 clinical trials). CBD seems not to have any negative effect on cognitive processing in rats. The clinical trials confirmed these findings in humans. One study found that repeated dosing with CBD may improve cognitive in people who use cannabis heavily but not individuals with neuropsychiatric disorders. Considering the context of neuropsychiatric disorders in animal models, CBD seems to reverse the harm caused by the experimental paradigms, such that the performance of these animals becomes similar to that of control animals. Conclusions: The results demonstrate that the chronic and acute administration of CBD seems not to impair cognition in humans without neuropsychiatric disorders. In addition, preclinical studies report promising results regarding the effects of CBD on the cognitive processing of animals. Future double-blind, placebo-controlled, randomized clinical trials with larger, less selective samples, with standardized tests, and using different doses of CBD in outpatients are of particular interest to elucidate the cognitive effects of CBD.

Sex and estrous cycle-linked differences in the effect of cannabidiol on panic-like responding in rats and mice

Clinical and preclinical studies point towards anxiolytic actions of cannabidiol (CBD), but its effect in panic disorder has been less explored and few studies consider effects in females. We here compared the effect of CBD on the response of male and female rats and mice to a panicogenic challenge; exposure to low O2 (rats) or high CO2 (mice) paying attention in females to possible effects of estrous cycle phase. Male and female Sprague-Dawley rats and C57BL/6 J mice were exposed to 7% O2 for 5 min (rats) or 20% CO2 (mice) and escape behaviour, which has been associated with panic attacks, was quantified as undirected jumps towards the gas chamber's ceiling. The effect of pretreatment with CBD (1-10 mg kg-1 i.p. in rats or 10-60 mg kg-1 i.p. in mice) was tested. The results showed that low O2 (rats) or high CO2 (mice) evoked escape in both sexes. In female rats the response was estrous cycle-sensitive: females in late diestrus made significantly more jumps than females in proestrus. In female mice escape was not influenced by estrous cycle phase and CBD was panicolytic. In female rats CBD attenuated escape behaviour in late diestrus phase but not in proestrus. In male rats and mice CBD had no effect on escape behaviour. Therefore, CBD is panicolytic in female rats and mice but not in males. In rats the effect is estrous cycle-sensitive: rats were most responsive to CBD in late diestrus. In mice higher doses were required to elicit effects and estrous cycle had no effect.

Emerging Therapeutic Potential of Cannabidiol (CBD) in Neurological Disorders: A Comprehensive Review

Cannabidiol (CBD), derived from Cannabis sativa, has gained remarkable attention for its potential therapeutic applications. This thorough analysis explores the increasing significance of CBD in treating neurological conditions including epilepsy, multiple sclerosis, Parkinson's disease, and Alzheimer's disease, which present major healthcare concerns on a worldwide scale. Despite the lack of available therapies, CBD has been shown to possess a variety of pharmacological effects in preclinical and clinical studies, making it an intriguing competitor. This review brings together the most recent findings on the endocannabinoid and neurotransmitter systems, as well as anti-inflammatory pathways, that underlie CBD's modes of action. Synthesized efficacy and safety assessments for a range of neurological illnesses are included, covering human trials, in vitro studies, and animal models. The investigation includes how CBD could protect neurons, control neuroinflammation, fend off oxidative stress, and manage neuronal excitability. This study emphasizes existing clinical studies and future possibilities in CBD research, addressing research issues such as regulatory complications and contradicting results, and advocates for further investigation of therapeutic efficacy and ideal dose methodologies. By emphasizing CBD's potential to improve patient well-being, this investigation presents a revised viewpoint on its suitability as a therapeutic intervention for neurological illnesses.

The effects of cannabidiol on worry and anxiety among high trait worriers: a double-blind, randomized placebo controlled trial

RATIONALE

Evidence suggests cannabidiol (CBD) displays broad therapeutic potential in the context of anxiety; however, no study has examined the effects of CBD on worry, a defining, cognitive feature of anxiety. Additionally, no study has examined the effects of an acute, single dose of CBD compared to repeated CBD administration.

OBJECTIVES

Within a sample of 63 individuals with elevated trait worry, the current study aimed to assess the effects of an empirically-derived high dose of CBD (i.e., 300mg) compared to a commercially-derived dose of CBD (i.e., 50mg) versus placebo on worry severity and anxiety symptoms after an acute dose and after a 2-week administration period.

RESULTS

Results indicated no effect of acute CBD dosing on worry severity or anxiety symptoms. Repeated CBD administration similarly did not impact worry severity; however, 300mg of CBD reduced anxiety symptoms across the 2-week administration period compared to placebo.

CONCLUSIONS

Taken together, these findings suggest 300mg of oral CBD does not attenuate cognitive symptoms of anxiety (i.e., worry), following both acute and repeated administration. Some evidence for repeated administration of 300mg on physical symptoms of anxiety was obtained. Findings from the current study suggest CBD's modest anxiolytic effects may be specific to the physical aspects of anxious arousal.

A systematic review of cannabidiol trials in neurodevelopmental disorders

Cannabis-derived compounds, such as cannabidiol (CBD) and delta-9-trans-tetrahydrocannabinol (THC), are increasingly prescribed for a range of clinical indications. These phyto-cannabinoids have multiple biological targets, including the body's endocannabinoid system. There is growing scientific interest in the use of CBD, a non-intoxicating compound, to ameliorate symptoms associated with neurodevelopmental disorders. However, its suitability as a pharmaceutical intervention has not been reliably established in these clinical populations. This systematic review examines the nine published randomised controlled trials (RCTs) that have probed the safety and efficacy of CBD in individuals diagnosed with attention deficit hyperactivity disorder, autism spectrum disorder, intellectual disability, Tourette Syndrome, and complex motor disorders. Studies were identified systematically through searching four databases: Medline, CINAHL complete, PsycINFO, and EMBASE. Inclusion criteria were randomised controlled trials involving CBD and participants with neurodevelopmental disorders. No publication year or language restrictions were applied. Relevant data were extracted from the identified list of eligible articles. After extraction, data were cross-checked between the authors to ensure consistency. Several trials indicate potential efficacy, although this possibility is currently too inconsistent across RCTs to confidently guide clinical usage. Study characteristics, treatment properties, and outcomes varied greatly across the included trials. The material lack of comparable RCTs leaves CBD's suitability as a pharmacological treatment for neurodevelopmental disorders largely undetermined. A stronger evidence base is urgently required to establish safety and efficacy profiles and guide the ever-expanding clinical uptake of cannabis-derived compounds in neurodevelopmental disorders. Prospero registration number: CRD42021267839.

Goods and Bads of the Endocannabinoid System as a Therapeutic Target: Lessons Learned after 30 Years

The cannabis derivative marijuana is the most widely used recreational drug in the Western world and is consumed by an estimated 83 million individuals (∼3% of the world population). In recent years, there has been a marked transformation in society regarding the risk perception of cannabis, driven by its legalization and medical use in many states in the United States and worldwide. Compelling research evidence and the Food and Drug Administration cannabis-derived cannabidiol approval for severe childhood epilepsy have confirmed the large therapeutic potential of cannabidiol itself, Δ9-tetrahydrocannabinol and other plant-derived cannabinoids (phytocannabinoids). Of note, our body has a complex endocannabinoid system (ECS)-made of receptors, metabolic enzymes, and transporters-that is also regulated by phytocannabinoids. The first endocannabinoid to be discovered 30 years ago was anandamide (N-arachidonoyl-ethanolamine); since then, distinct elements of the ECS have been the target of drug design programs aimed at curing (or at least slowing down) a number of human diseases, both in the central nervous system and at the periphery. Here a critical review of our knowledge of the goods and bads of the ECS as a therapeutic target is presented to define the benefits of ECS-active phytocannabinoids and ECS-oriented synthetic drugs for human health. SIGNIFICANCE STATEMENT: The endocannabinoid system plays important roles virtually everywhere in our body and is either involved in mediating key processes of central and peripheral diseases or represents a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of the components of this complex system, and in particular of key receptors (like cannabinoid receptors 1 and 2) and metabolic enzymes (like fatty acid amide hydrolase and monoacylglycerol lipase), will advance our understanding of endocannabinoid signaling and activity at molecular, cellular, and system levels, providing new opportunities to treat patients.

Interactive Effects of Ayahuasca and Cannabidiol in Social Cognition in Healthy Volunteers: A Pilot, Proof-of-Concept, Feasibility, Randomized-Controlled Trial

BACKGROUND

Serotonergic hallucinogens and cannabinoids may alter the recognition of emotions in facial expressions (REFE). Cannabidiol (CBD) attenuates the psychoactive effects of the cannabinoid-1 agonist tetrahydrocannabinol. Ayahuasca is a dimethyltryptamine-containing hallucinogenic decoction. It is unknown if CBD may moderate and attenuate the effects of ayahuasca on REFE.

PROCEDURES

Seventeen healthy volunteers participated in a 1-week preliminary parallel-arm, randomized controlled trial for 18 months. Volunteers received a placebo or 600 mg of oral CBD followed by oral ayahuasca (1 mL/kg) 90 minutes later. Primary outcomes included REFE and empathy tasks (coprimary outcome). Tasks were performed at baseline and 6.5 hours, 1 and 7 days after the interventions. Secondary outcome measures included subjective effects, tolerability, and biochemical assessments.

RESULTS

Significant reductions (all P values <0.05) only in reaction times were observed in the 2 tasks in both groups, without between-group differences. Furthermore, significant reductions in anxiety, sedation, cognitive deterioration, and discomfort were observed in both groups, without between-group differences. Ayahuasca, with or without CBD, was well tolerated, producing mainly nausea and gastrointestinal discomfort. No clinically significant effects were observed on cardiovascular measurements and liver enzymes.

CONCLUSIONS

There was no evidence of interactive effects between ayahuasca and CBD. The safety of separate and concomitant drug intake suggests that both drugs could be applied to clinical populations with anxiety disorders and in further trials with larger samples to confirm findings.

The therapeutic potential of purified cannabidiol

The use of cannabidiol (CBD) for therapeutic purposes is receiving considerable attention, with speculation that CBD can be useful in a wide range of conditions. Only one product, a purified form of plant-derived CBD in solution (Epidiolex), is approved for the treatment of seizures in patients with Lennox-Gastaut syndrome, Dravet syndrome, or tuberous sclerosis complex. Appraisal of the therapeutic evidence base for CBD is complicated by the fact that CBD products sometimes have additional phytochemicals (like tetrahydrocannabinol (THC)) present, which can make the identification of the active pharmaceutical ingredient (API) in positive studies difficult. The aim of the present review is to critically review clinical studies using purified CBD products only, in order to establish the upcoming indications for which purified CBD might be beneficial. The areas in which there is the most clinical evidence to support the use of CBD are in the treatment of anxiety (positive data in 7 uncontrolled studies and 17 randomised controlled trials (RCTs)), psychosis and schizophrenia (positive data in 1 uncontrolled study and 8 RCTs), PTSD (positive data in 2 uncontrolled studies and 4 RCTs) and substance abuse (positive data in 2 uncontrolled studies and 3 RCTs). Seven uncontrolled studies support the use of CBD to improve sleep quality, but this has only been verified in one small RCT. Limited evidence supports the use of CBD for the treatment of Parkinson's (3 positive uncontrolled studies and 2 positive RCTs), autism (3 positive RCTs), smoking cessation (2 positive RCTs), graft-versus-host disease and intestinal permeability (1 positive RCT each). Current RCT evidence does not support the use of purified oral CBD in pain (at least as an acute analgesic) or for the treatment of COVID symptoms, cancer, Huntington's or type 2 diabetes. In conclusion, published clinical evidence does support the use of purified CBD in multiple indications beyond epilepsy. However, the evidence base is limited by the number of trials only investigating the acute effects of CBD, testing CBD in healthy volunteers, or in very small patient numbers. Large confirmatory phase 3 trials are required in all indications.

Medicinal cannabis for psychiatry-related conditions: an overview of current Australian prescribing

Objective: Evidence is accumulating that components of the Cannabis sativa plant may have therapeutic potential in treating psychiatric disorders. Medicinal cannabis (MC) products are legally available for prescription in Australia, primarily through the Therapeutic Goods Administration (TGA) Special Access Scheme B (SAS-B). Here we investigated recent prescribing practices for psychiatric indications under SAS-B by Australian doctors. Methods: The dataset, obtained from the TGA, included information on MC applications made by doctors through the SAS-B process between 1st November 2016 and 30th September 2022 inclusive. Details included the primary conditions treated, patient demographics, prescriber location, product type (e.g., oil, flower or capsule) and the general cannabinoid content of products. The conditions treated were categorized according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR). Trends in prescribing for conditions over time were analyzed via polynomial regression, and relationships between categorical variables determined via correspondence analyses. Results: Approximately 300,000 SAS-B approvals to prescribe MC had been issued in the time period under investigation. This included approvals for 38 different DSM-5-TR defined psychiatric conditions (33.9% of total approvals). The majority of approvals were for anxiety disorders (66.7% of psychiatry-related prescribing), sleep-wake disorders (18.2%), trauma- and stressor-related disorders (5.8%), and neurodevelopmental disorders (4.4%). Oil products were most prescribed (53.0%), followed by flower (31.2%) and other inhaled products (12.4%). CBD-dominant products comprised around 20% of total prescribing and were particularly prevalent in the treatment of autism spectrum disorder. The largest proportion of approvals was for patients aged 25-39 years (46.2% of approvals). Recent dramatic increases in prescribing for attention deficit hyperactivity disorder were identified. Conclusion: A significant proportion of MC prescribing in Australia is for psychiatry-related indications. This prescribing often appears somewhat "experimental", given it involves conditions (e.g., ADHD, depression) for which definitive clinical evidence of MC efficacy is lacking. The high prevalence of THC-containing products being prescribed is of possible concern given the psychiatric problems associated with this drug. Evidence-based clinical guidance around the use of MC products in psychiatry is lacking and would clearly be of benefit to prescribers.

Behavioral effects induced by the cannabidiol analogs HU-502 and HU-556

Cannabidiol is a phytocannabinoid that lacks the psychotomimetic properties of Δ9-tetrahydrocannabinol (THC), the main psychoactive Cannabis sativa component. Cannabidiol has several potential therapeutic properties, including anxiolytic, antidepressant, and antipsychotic; however, cannabidiol has low oral bioavailability, which can limit its clinical use. Here, we investigated if two cannabidiol analogs, HU-502 and HU-556, would be more potent than cannabidiol in behavioral tests predictive of anxiolytic, antidepressant, and antipsychotic effects. Different doses (0.01-3 mg/kg; intraperitoneally) of HU-556 and HU-502 were tested in male Swiss mice submitted to the elevated plus maze (EPM), forced swimming test (FST), and amphetamine-induced-prepulse inhibition (PPI) disruption and hyperlocomotion. Cannabidiol is effective in these tests at a dose range of 15-60 mg/kg in mice. We also investigated if higher doses of HU-556 (3 and 10 mg/kg) and HU-502 (10 mg/kg) produced the cannabinoid tetrad (hypolocomotion, catalepsy, hypothermia, and analgesia), which is induced by THC-like compounds. HU-556 (0.1 and 1 mg/kg) increased the percentage of open arm entries (but not time) in the EPM, decreased immobility time in the FST, and attenuated amphetamine-induced PPI disruption. HU-502 (1 and 3 mg/kg) decreased amphetamine-induced hyperlocomotion and PPI impairment. HU-556, at high doses, caused catalepsy and hypolocomotion, while HU-502 did not. These findings suggest that similar to cannabidiol, HU-556 could induce anxiolytic, antidepressant, and antipsychotic-like effects and that HU-502 has antipsychotic properties. These effects were found at a dose range devoid of cannabinoid tetrad effects.

Cannabidiol for the Treatment of Brain Disorders: Therapeutic Potential and Routes of Administration

The use of cannabidiol (CBD) for treating brain disorders has gained increasing interest. While the mechanism of action of CBD in these conditions is still under investigation, CBD has been shown to affect numerous different drug targets in the brain that are involved in brain disorders. Here we review the preclinical and clinical evidence on the potential therapeutic use of CBD in treating various brain disorders. Moreover, we also examine various drug delivery approaches that have been applied to CBD. Due to the slow absorption and low bioavailability with the current oral CBD therapy, more efficient routes of administration to bypass hepatic metabolism, particularly pulmonary delivery, should be considered. Comparison of pharmacokinetic studies of different delivery routes highlight the advantages of intranasal and inhalation drug delivery over other routes of administration (oral, injection, sublingual, buccal, and transdermal) for treating brain disorders. These two routes of delivery, being non-invasive and able to achieve fast absorption and increase bioavailability, are attracting increasing interest for CBD applications, with more research and development expected in the near future.