Cannabidiol as a Therapeutic Alternative for Post-traumatic Stress Disorder: From Bench Research to Confirmation in Human Trials

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.

Enhancing massed prolonged exposure with cannabidiol to improve posttraumatic stress disorder: Design and methodology of a pilot randomized clinical trial

Background

The impact of posttraumatic stress disorder (PTSD) is substantial and often results in pervasive functional impairments. Although evidence-based treatments for PTSD are established, there remains room for improvement as many individuals continue to meet diagnostic criteria even after successful treatment completion. Cannabidiol (CBD) has attracted considerable attention based on its potential to treat a myriad of health conditions. CBD may decrease anxiety and facilitate extinction learning processes, two critical targets of trauma-focused psychotherapies. We present the design and methods for a pilot randomized clinical trial to examine the combination of CBD and prolonged exposure for PTSD.

Methods

Participants (n = 24) will be randomized to CBD or placebo for 18 days delivered in combination with ten daily prolonged exposure sessions over two weeks. The study medication will be Epidiolex® (250 mg BID). The PTSD Checklist for DSM-5 will be the primary outcome to assess PTSD severity at baseline, during treatment, and at 1-month follow-up. Blood, saliva, and heart rate will be collected during treatment to assess intervention effects on biological outcomes related to PTSD and the endocannabinoid system.

Results

Consistent with the purpose of a pilot, our goals are to evaluate the feasibility of study procedures, safety of the intervention, and the preliminary effect of CBD to inform a larger trial. Descriptive and inferential statistics will be used to address study aims.

Conclusion

Findings will inform decision making on combining CBD with behavioral interventions for PTSD to enhance outcomes and mitigate the morbidity of this debilitating condition.

The Effects of Cannabidiol and δ-9-Tetrahydrocannabinol in Social Cognition: A Naturalistic Controlled Study

Background: Social cognition abilities such as empathy and the Theory of Mind (ToM) have been shown to be impaired in neuropsychiatric conditions such as psychotic, autistic, and bipolar disorders. The endocannabinoid system (ECS) seems to play a role in social behavior and emotional processing while it also seems to play a role in those neuropsychiatric conditions showing social cognition impairments. Main plant cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) modulate the ECS and, due to their opposite effects, have been proposed as both cause and treatment for neuropsychiatric-related disorders such as schizophrenia, anxiety, or post-traumatic stress disorder (PTSD). The aim of this study was to test the effects of THC and CBD on social cognition abilities in chronic cannabis users. Method: Eighteen members from a cannabis social club were tested for social cognition effects under the effects of different full spectrum cannabis extracts containing either THC, CBD, THC+CBD, or placebo in a naturalistic randomized double-blind crossover placebo-controlled study. Results: Results showed that participants under the effects of THC showed lower cognitive empathy when compared with the effects of CBD but not when those were compared with THC+CBD or placebo. Also, participants showed higher cognitive ToM under the effects of CBD when compared with the effects of placebo, but not when those were compared with THC or THC+CBD. However, we did not find differences on the emotional scales for empathy or ToM. Conclusions: This study provides evidence for the interaction between the effects of THC and CBD and social cognition abilities in a naturalistic environment, which can be of special interest for the clinical practice of medical cannabis on neuropsychiatric disorders. We show for the first time that CBD can improve ToM abilities in chronic cannabis users. Our results might help to understand the role of the ECS in social cognition, and their association with psychiatric and neurodevelopmental disorders such as schizophrenia or autism. Finally, we demonstrate how reliable methodologies can be implemented in naturalistic environments to collect valid ecological evidence outside classic laboratory settings.

Novel Pharmacological Targets of Post-Traumatic Stress Disorders

Post-traumatic stress disorder (PTSD) is a psychopathological condition with a heterogeneous clinical picture that is complex and challenging to treat. Its multifaceted pathophysiology still remains an unresolved question and certainly contributes to this issue. The pharmacological treatment of PTSD is mainly empirical and centered on the serotonergic system. Since the therapeutic response to prescribed drugs targeting single symptoms is generally inconsistent, there is an urgent need for novel pathogenetic hypotheses, including different mediators and pathways. This paper was conceived as a narrative review with the aim of debating the current pharmacological treatment of PTSD and further highlighting prospective targets for future drugs. The authors accessed some of the main databases of scientific literature available and selected all the papers that fulfilled the purpose of the present work. The results showed that most of the current pharmacological treatments for PTSD are symptom-based and show only partial benefits; this largely reflects the limited knowledge of its neurobiology. Growing, albeit limited, data suggests that the hypothalamic-pituitary-adrenal axis, opioids, glutamate, cannabinoids, oxytocin, neuropeptide Y, and microRNA may play a role in the development of PTSD and could be targeted for novel treatments. Indeed, recent research indicates that examining different pathways might result in the development of novel and more efficient drugs.

Cannabidiol Differentially Modulates Synaptic Release and Cellular Excitability in Amygdala Subnuclei

Cannabidiol (CBD) is a non-psychoactive constituent of the Cannabis plant that has purported effectiveness in treating an array of stress-related neuropsychiatric disorders. The amygdala is a subcortical brain structure that regulates emotional behavior, and its dysfunction has been linked to numerous disorders including anxiety and posttraumatic stress disorder. Despite this, the direct effects of CBD on synaptic and cellular function in the amygdala are not known. Using electrophysiology and pharmacology, we report that CBD reduces presynaptic neurotransmitter release in the amygdala, and these effects are dependent on subnucleus and cell type. Furthermore, CBD broadly decreases cellular excitability across amygdala subnuclei. These data reveal physiological mechanisms by which CBD modulates amygdala activity and could provide insights into how CBD could affect emotional and stress-related behavioral responses.

Neuropharmacological Modulation of N-methyl-D-aspartate, Noradrenaline and Endocannabinoid Receptors in Fear Extinction Learning: Synaptic Transmission and Plasticity

Learning to recognize and respond to potential threats is crucial for survival. Pavlovian threat conditioning represents a key paradigm for investigating the neurobiological mechanisms of fear learning. In this review, we address the role of specific neuropharmacological adjuvants that act on neurochemical synaptic transmission, as well as on brain plasticity processes implicated in fear memory. We focus on novel neuropharmacological manipulations targeting glutamatergic, noradrenergic, and endocannabinoid systems, and address how the modulation of these neurobiological systems affects fear extinction learning in humans. We show that the administration of N-methyl-D-aspartate (NMDA) agonists and modulation of the endocannabinoid system by fatty acid amide hydrolase (FAAH) inhibition can boost extinction learning through the stabilization and regulation of the receptor concentration. On the other hand, elevated noradrenaline levels dynamically modulate fear learning, hindering long-term extinction processes. These pharmacological interventions could provide novel targeted treatments and prevention strategies for fear-based and anxiety-related disorders.

The Effects of Cannabidiol on the Driving Performance of Healthy Adults: A Pilot RCT

Introduction

A common side effect of cannabidiol is drowsiness, which could impact safe driving. This study's purpose was to determine the feasibility and whether cannabidiol impacts simulated driving performance.

Methods

This was a randomized, parallel-group, sex-stratified, double-blind, pilot trial that consisted of a volunteer sample of healthy, currently driving college students. Participants were randomized and allocated to receive a placebo (n=19) or 300 mg cannabidiol (n=21) by oral syringe. Participants completed a ~40-minute driving simulation. A post-test survey assessed acceptability. The primary outcomes were mean SD of lateral position, total percent time the individual drove outside travel lanes, total collisions, time to initial collision, and mean brake reaction time. Outcomes were compared between groups using Student's t-tests and Cox proportional hazards models.

Results

None of the relationships were statistically significant, but the study was underpowered. Those receiving cannabidiol experienced slightly more collisions (0.90 vs 0.68, p=0.57) and had slightly higher mean SD of lateral position and slower brake reaction times (0.60 vs 0.58 seconds, p=0.61) than those who received placebo. Participants were satisfied with their experiences.

Conclusions

The design was feasible. Larger trials may be warranted because it is unclear whether the small differences in performance seen in the cannabidiol group were clinically relevant.

Multinational Association of Supportive Care in Cancer (MASCC) guidelines: cannabis for psychological symptoms including insomnia, anxiety, and depression

PURPOSE

During the treatment of cancer, 18% of patients use cannabis for symptom management. Anxiety, depression, and sleep disturbances are common symptoms in cancer. A systematic review of the evidence for cannabis use for psychological symptoms in cancer patients was undertaken to develop a guideline.

METHODS

A literature search of randomized trials and systematic reviews was undertaken up to November 12, 2021. Studies were independently assessed for evidence by two authors and then evaluated by all authors for approval. The literature search involved MEDLINE, CCTR, EMBASE, and PsychINFO databases. Inclusion criteria included randomized control trials and systematic reviews on cannabis versus placebo or active comparator in patients with cancer and psychological symptom management (anxiety, depression, and insomnia).

RESULTS

The search yielded 829 articles; 145 from Medline, 419 from Embase, 62 from PsychINFO, and 203 from CCTR. Two systematic reviews and 15 randomized trials (4 on sleep, 5 on mood, 6 on both) met eligibility criteria. However, no studies specifically assessed the efficacy of cannabis on psychological symptoms as primary outcomes in cancer patients. The studies varied widely in terms of interventions, control, duration, and outcome measures. Six of 15 RCTs suggested benefits (five for sleep, one for mood).

CONCLUSION

There is no high-quality evidence to recommend the use of cannabis as an intervention for psychological symptoms in patients with cancer until more high-quality research demonstrates benefit.

Cannabidiol attenuates fear memory expression in female rats via hippocampal 5-HT1A but not CB1 or CB2 receptors

Growing evidence from male rodent and human studies suggests that cannabidiol (CBD) modulates the expression of aversive memories and anxiety-related responses. The limited data on whether and how CBD influences these aspects in females could have therapeutic implications given the increased susceptibility of women to anxiety- and stress-related disorders relative to men. Female studies are also essential to examine inherent aspects that potentially contribute to differences in responsiveness to CBD. Here we addressed these questions in adult female rats. Contextually fear-conditioned animals acutely treated with CBD (1.0-10 mg/kg) were tested 45 min later. In subsequent experiments, we investigated the estrous cycle effects and the contribution of dorsal hippocampus (DH) serotonin 1A (5-HT1A) and cannabinoid types 1 (CB1) and 2 (CB2) receptors to CBD-induced effects on memory retrieval/expression. The effects of pre-retrieval systemic or intra-DH CBD administration on subsequent fear extinction were also assessed. Lastly, we evaluated the open arms avoidance and stretched-attend postures in females exposed to the elevated plus-maze after systemic CBD treatment. CBD 3.0 and 10 mg/kg administered before conditioned context exposure reduced females' freezing. This action remained unchanged across the estrous cycle and involved DH 5-HT1A receptors activation. Pre-retrieval CBD impaired memory reconsolidation and lowered fear during early extinction. CBD applied directly to the DH was sufficient to reproduce the effects of systemic CBD treatment. CBD 3.0 and 10 mg/kg reduced anxiety-related responses scored in the elevated plus-maze. Our findings demonstrate that CBD attenuates the behavioral manifestation of learned fear and anxiety in female rats.

The NLRP3 Inflammasome in Stress Response: Another Target for the Promiscuous Cannabidiol

Many psychiatric patients do not respond to conventional therapy. There is a vast effort to investigate possible mechanisms involved in treatment resistance, trying to provide better treatment options, and several data points toward a possible involvement of inflammatory mechanisms. Microglia, glial, and resident immune cells are involved in complex responses in the brain, orchestrating homeostatic functions, such as synaptic pruning and maintaining neuronal activity. In contrast, microglia play a major role in neuroinflammation, neurodegeneration, and cell death. Increasing evidence implicate microglia dysfunction in neuropsychiatric disorders. The mechanisms are still unclear, but one pathway in microglia has received increased attention in the last 8 years, i.e., the NLRP3 inflammasome pathway. Stress response and inflammation, including microglia activation, can be attenuated by Cannabidiol (CBD). CBD has antidepressant, anti-stress, antipsychotic, anti-inflammatory, and other properties. CBD effects are mediated by direct or indirect modulation of many receptors, enzymes, and other targets. This review will highlight some findings for neuroinflammation and microglia involvement in stress-related psychiatric disorders, particularly addressing the NLRP3 inflammasome pathway. Moreover, we will discuss evidence and mechanisms for CBD effects in psychiatric disorders and animal models and address its potential effects on stress response via neuroinflammation and NLRP3 inflammasome modulation.

Improved Post-Traumatic Stress Disorder Symptoms and Related Sleep Disturbances after Initiation of Medical Marijuana Use: Evidence from a Prospective Single Arm Pilot Study

Introduction

Post-traumatic stress disorder (PTSD) is a debilitating disorder experienced by a subgroup of individuals following a life-threatening trauma. Several US states have passed laws permitting the medical use of marijuana (MMJ) by individuals with PTSD, despite very little scientific indication on the appropriateness of marijuana as a therapy for PTSD. This prospective pilot study of adults with confirmed PTSD in Florida (FL) investigated whether PTSD symptoms, sleep quality, affect, and general physical and mental health/well-being improved post-initiation of MMJ treatment.

Methods

Participants, N = 15, were recruited from two MMJ clinics in Gainesville and Jacksonville, FL. To be eligible, participants had to be 18 years of age or older, not currently on MMJ, and willing to abstain from recreational marijuana, if using any, until the State Medical Cannabis Card was obtained, screen positive for PTSD. Participants were assessed at baseline (pre-MMJ initiation) and 30 and 70 days post-MMJ initiation using the Pittsburgh Sleep Quality Index (PSQI), PTSD Checklist for DSM-5 (PCL-5), Positive and Negative Affect Schedule (PANAS), PROMIS Global Health V1.2, and semi-structured marijuana and other substance use assessment.

Results

PTSD symptom severity as measured by total PCL-5 score improved significantly at 30- and 70-day follow-ups. Similarly, statistically significant reductions in nightmares were reported at 30- and 70-day follow-ups. Corresponding improvements in sleep were noticed with participants reporting increased duration of sleep hours, sleep quality, sleep efficiency, and total PSQI score. Likewise, negative affect and global mental health improved significantly at follow-up. According to the post hoc analyses, the most statistically significant changes occurred between baseline and 30-day follow-up. The exception to this pattern was nightmares, which did not show significant improvement until day 70.

Conclusion

The findings of this study highlight the potential of MMJ in improving patient outcomes for those with PTSD, particularly concerning sleep disturbances, which often do not respond to currently available treatments.

Regulation of DNA Methylation by Cannabidiol and Its Implications for Psychiatry: New Insights from In Vivo and In Silico Models

Cannabidiol (CBD) is a non-psychotomimetic compound present in cannabis sativa. Many recent studies have indicated that CBD has a promising therapeutic profile for stress-related psychiatric disorders, such as anxiety, schizophrenia and depression. Such a diverse profile has been associated with its complex pharmacology, since CBD can target different neurotransmitter receptors, enzymes, transporters and ion channels. However, the precise contribution of each of those mechanisms for CBD effects is still not yet completely understood. Considering that epigenetic changes make the bridge between gene expression and environment interactions, we review and discuss herein how CBD affects one of the main epigenetic mechanisms associated with the development of stress-related psychiatric disorders: DNA methylation (DNAm). Evidence from in vivo and in silico studies indicate that CBD can regulate the activity of the enzymes responsible for DNAm, due to directly binding to the enzymes and/or by indirectly regulating their activities as a consequence of neurotransmitter-mediated signaling. The implications of this new potential pharmacological target for CBD are discussed in light of its therapeutic and neurodevelopmental effects.

Use of Cannabidiol (CBD) oil in the treatment of PTSD: Study design and rationale for a placebo-controlled randomized clinical trial

BACKGROUND

The burden of illness for PTSD is staggering and confers significant interference in work, social functioning, as well as increased risk for other physical and mental health problems. Recently, there's been considerable attention paid to the potential therapeutic use of cannabidiol (CBD) products in the treatment of a variety of physical and mental health problems. The endocannabinoid system (ECS) is a logical therapeutic target for combating PTSD and other fear-based disorders given that cannabinoid receptors and other molecular mediators crucial for ECS signaling are richly expressed in a variety of brain regions that govern the regulation of learned fear and defensive behavior.

METHODS

This is an 8-week single-site Phase II randomized double-blind placebo-controlled fixed dose clinical trial. Participants recruited throughout the United States (N = 150) meeting DSM-5 criteria for posttraumatic stress disorder are randomly assigned to one of three treatment arms: (a) 300 mg CBD Isolate; (b) 300 mg CBD Broad Spectrum; and (c) Placebo oil. The primary outcome is PTSD symptom severity as indexed by the PTSD Checklist for DSM-5 (PCL-5) assessed at post treatment (Week 9) and follow-up (Week 13). Secondary outcomes including patient-rated depression, overall disability, anxiety, quality of life, and alcohol use are assessed weekly throughout the trial. Safety and CBD adherence are assessed daily throughout the trial.

CONCLUSION

This is the first placebo-controlled clinical trial investigating (a) CBD for the treatment of PTSD; and (b) the first study to test the relative efficacy of CBD Isolate vs CBD Broad Spectrum. Trial registration ClinicalTrials.gov registered (12/12/2019), trial identifier NCT04197102.

PROTOCOL VERSION

issued 08/04/2022, protocol amendment number #2019-05-0123.

Hemp in Animal Diets—Cannabidiol

In recent years, interest in hemp use has grown owing to its chemical and medicinal properties. Several parts of this plant, such as seeds, leaves, flowers, and stems are used in medicine, industry, and environmental preservation. Although there were legal restrictions on hemp exploitation in some countries due to the trace presence of THC as a psychoactive element, many countries have legalized it in recent years. Cannabidiol or CBD is a non-psychoactive phytocannabinoid that can activate the endocannabinoid system and its receptors in the central and peripheral nervous system in bodies of different species. Cannabidiol has anti-inflammatory, antioxidative, analgesic, and anti-depressant effects. This review investigates various aspects of cannabidiol use and its potential in animals and humans.

Cannabidiol Prevents Spontaneous Fear Recovery after Extinction and Ameliorates Stress-Induced Extinction Resistance

Cannabidiol, the main non-psychotropic constituent of cannabis, has potential as a treatment for anxiety-related disorders since it reduces learned fear expression and enhances fear extinction. The return of fear over time after successful extinction and stress-induced extinction resistance are potential barriers to the treatment of these disorders with extinction-based psychological therapy. In two experiments using rats subjected to auditory fear conditioning, we determined the effects of systemic cannabidiol treatment on (1) delayed extinction and later spontaneous fear recovery, and (2) extinction resistance caused by immediate extinction (the immediate extinction deficit (IED)). In Experiment 1, cannabidiol was given before delayed extinction occurring 24 h after conditioning, with extinction recall and spontaneous fear recovery tested drug-free 1 and 21 days after extinction, respectively. We found that cannabidiol had no effect on extinction recall but it prevented spontaneous fear recovery. In Experiment 2, the IED procedure was first validated, with immediate extinction occurring 30 min after conditioning. We confirmed that immediate extinction impaired extinction recall, compared to delayed extinction. Next, cannabidiol was given before immediate or no extinction, with extinction recall tested drug-free the next day. We found that cannabidiol rescued the IED, which did not involve effects on fear memory consolidation. In summary, cannabidiol prevented spontaneous fear recovery after delayed extinction and ameliorated extinction resistance caused by immediate extinction. Although the pharmacological mechanisms underlying these effects remain to be determined, our results add to evidence indicating that cannabidiol might prove useful as an adjunct for potentiating the psychological treatment of anxiety-related disorders.

The Cannabis Constituent Cannabigerol Does Not Disrupt Fear Memory Processes or Stress-Induced Anxiety in Mice

Introduction: Medicinal cannabis has proliferated around the world and there is increasing interest in the therapeutic potential of individual plant-derived cannabinoids (phytocannabinoids). Preclinical evidence suggests the phytocannabinoid cannabigerol (CBG) could be useful in treating brain disorders, including stress and anxiety-related disorders. In this study, we aimed to explore whether CBG disrupts various contextually conditioned fear memory processes and trauma-induced anxiety-related behavior in a mouse model of post-traumatic stress disorder (PTSD). Materials and Methods: All mice underwent contextual fear conditioning. CBG was administered between 1 and 60 mg/kg intraperitoneally (i.p.). We first assessed the effects of repeated CBG exposure on long-term fear memories. We also examined whether acute CBG affected various fear memory processes, namely expression, acquisition, consolidation, and reconsolidation of conditioned fear. Finally, the effect of acute CBG administration on stress-induced anxiety in the light/dark test was assessed. Results: Repeated CBG exposure did not affect long-term conditioned fear that was observed 24 days after the conditioning session. Moreover, acute CBG administration did not influence the acquisition, consolidation, reconsolidation, or expression of contextually conditioned fear. Acute CBG treatment also did not affect stress-induced anxiety-related behaviors in the light/dark test. Conclusions: CBG was ineffective in disrupting long-term fear memories, various conditioned fear memory processes, or stress-induced anxiety-related behavior in mice. These preclinical data suggest CBG may have limited scope in the treatment of PTSD and stress-related anxiety.

Effects of cannabidiol on symptoms induced by the recall of traumatic events in patients with posttraumatic stress disorder

Studies with cannabidiol (CBD) suggest that this compound has anxiolytic properties and may mediate the reconsolidation and extinction of aversive memories. The objective of this study was to test whether the administration of CBD 300 mg before the recall of traumatic events attenuated symptoms usually induced by recall in subjects diagnosed with posttraumatic stress disorder (PTSD) and if its potential effects interfere with the reconsolidation of aversive memories. The double-blind trial included 33 participants of both sexes, aged between 18 and 60 years, diagnosed with PTSD according to the SCID-5 and randomly allocated to two groups treated with CBD (n = 17) and placebo (n = 16). In the first experimental section, participants were matched by sex, age, body mass index (BMI), and PTSD symptoms as assessed with the Posttraumatic Stress Disorder Checklist (PCL-5). On the same day, participants prepared the behavior test, recording accounts of their traumas in digital audio for a minute and a half and then imagining the trauma for 30 s. After 7 days, participants received CBD (300 mg) or placebo and performed the behavioral test, listening to the trauma account and imagining themselves in that situation. Before and after the behavioral test, subjective changes in mood and anxiety were recorded (Visual and Analogical Mood Scale - VAMS and STAI-state), along with physiological correlates of anxiety blood pressure (BP), heart rate (HR), and salivary cortisol (SC). Seven days later, participants underwent the same procedures as the previous session, but without the pharmacological intervention, to assess the effect on reconsolidation of traumatic memories. We found that CBD significantly attenuated the increase in the VAMS scale cognitive impairment factor scores, under the CBD's effect, with this effect remaining 1 week after drug administration. No significant differences between the effects of CBD and placebo on anxiety, alertness, and discomfort induced by the recall of the traumatic event during the pharmacological intervention and in the subsequent week, in the absence of it. There were no significant differences between the CBD and placebo groups regarding physiological data (BP, HR, and SC). The attenuation of cognitive impairments during trauma recall under the effect of CBD may have interfered with the reconsolidation of traumatic memories concerning its association with cognitive impairments.

A scoping review of the use of cannabidiol in psychiatric disorders

Cannabidiol (CBD) has become a fast-growing avenue for research in psychiatry, and clinicians are challenged with understanding the implications of CBD for treating mental health disorders. The goal of this review is to serve as a guide for mental health professionals by providing an overview of CBD and a synthesis the current evidence within major psychiatric disorders. PubMed and PsycINFO were searched for articles containing the terms "cannabidiol" in addition to major psychiatric disorders and symptoms, yielding 2952 articles. Only randomized controlled trials or within-subject studies investigating CBD as a treatment option for psychiatric disorders (N = 16) were included in the review. Studies were reviewed for psychotic disorders (n = 6), anxiety disorders (n = 3), substance use disorders (tobacco n = 3, cannabis n = 2, opioid n = 1), and insomnia (n = 1). There were no published studies that met inclusion criteria for alcohol or stimulant use disorder, PTSD, ADHD, autism spectrum disorder, or mood disorders. Synthesis of the CBD literature indicates it is generally safe and well tolerated. The most promising preliminary findings are related to the use of CBD in psychotic symptoms and anxiety. There is currently not enough high-quality evidence to suggest the clinical use of CBD for any psychiatric disorder.

Comparison of the Effectiveness and Tolerability of Nabiximols (THC:CBD) Oromucosal Spray versus Oral Dronabinol (THC) as Add-on Treatment for Severe Neuropathic Pain in Real-World Clinical Practice: Retrospective Analysis of the German Pain e-Registry

Purpose

To compare the effectiveness and tolerability of add-on treatment with nabiximols (NBX: delta-9-tetrahydrocannabinol: cannabidiol) oromucosal spray or oral dronabinol (DRO: synthetic tetrahydrocannabinol) in patients with severe neuropathic pain poorly responsive to established treatments.

Methods

An analysis was conducted of anonymized, propensity score-matched real-world data from the German Pain e-Registry, using a sequential non-inferiority superiority approach, for adult outpatients with neuropathic pain who had initiated treatment with NBX or DRO between 10 March 2017 and 31 December 2019. The primary effectiveness variable was percent change from baseline in a 9-factor aggregated symptom relief (ASR-9) score, a composite index of nine distinct pain- and health-related parameters assessed using validated patient-reported instruments. Safety was assessed by the incidence of physician-confirmed treatment-related adverse events (TRAEs), and TRAEs leading to discontinuation.

Results

Propensity score-matched data were analyzed for 337 patients treated with NBX and 337 patients treated with DRO. Mean (standard deviation) THC dose over the 24-week evaluation period was 16.6 (6.5) mg for NBX and 17.2 (7.6) mg for DRO (p<0.001). Median (standard error) improvement relative to baseline in the ASR-9 composite score was 55.4% (0.5) for NBX and 40.5% (0.5) for DRO (least squares mean difference, 14.0 (0.7), 95% confidence interval 12.6–15.4; p<0.001), and incidences of TRAEs (21.1 vs 35%) and TRAE-related discontinuations (5.9 vs 14.8%) were significantly lower with NBX than DRO (p<0.001 for both), collectively indicating pre-specified non-inferiority and superiority of NBX. More NBX- than DRO-treated patients discontinued non-cannabinoid background pain medications and rescue analgesics, especially opioid analgesics (p<0.001 for both).

Conclusion

Add-on treatment with cannabinoids is effective for treatment of severe neuropathic pain with inadequate response to established treatments. In daily practice, NBX had superior effectiveness and tolerability compared to DRO. The results emphasize the importance of combining CBD with THC in this patient population.

Resilience to the effects of social stress on vulnerability to developing drug addiction

We review the still scarce but growing literature on resilience to the effects of social stress on the rewarding properties of drugs of abuse. We define the concept of resilience and how it is applied to the field of drug addiction research. We also describe the internal and external protective factors associated with resilience, such as individual behavioral traits and social support. We then explain the physiological response to stress and how it is modulated by resilience factors. In the subsequent section, we describe the animal models commonly used in the study of resilience to social stress, and we focus on the effects of chronic social defeat (SD), a kind of stress induced by repeated experience of defeat in an agonistic encounter, on different animal behaviors (depression- and anxiety-like behavior, cognitive impairment and addiction-like symptoms). We then summarize the current knowledge on the neurobiological substrates of resilience derived from studies of resilience to the effects of chronic SD stress on depression- and anxiety-related behaviors in rodents. Finally, we focus on the limited studies carried out to explore resilience to the effects of SD stress on the rewarding properties of drugs of abuse, describing the current state of knowledge and suggesting future research directions.

Benefits, toxicity and current market of cannabidiol in edibles

The commercialization of products with cannabidiol (CBD) has undergone a significant increase. These products can be presented in different forms such as baked goods, gummies or beverages (such as kombucha, beer or teas, among others) using wide concentrations ranges. The use of CBD in edibles favors its consumption, for medicinal users, during the work week, avoid its possible social stigma and facilitates its transport. These products can be purchased on store shelves and online. There is a large number of specialized studies, in which the possible advantages of CBD consumption are described in the preclinical and clinical trials. It is also necessary to recognize the existence of other works revealing that the excessive consumption of CBD could have some repercussions on health. In this review, it is analyzed the composition and properties of Cannabis sativa L., the health benefits of cannabinoids (focusing on CBD), its consumption, its possible toxicological effects, a brief exposition of the extraction process, and a collection of different products that contain CBD in its composition.

[Anatomy and physiology of traumatic stress]

Facing a more or less intrusive stress, some individuals can cope as they are more resilient, while others get traumatized and further develop a Post Traumatic Stress Disorder (PTSD). Individuals are not equal facing traumatic stress for genetic/epigenetic or personal reasons. This review analyzes from animal models to human, the neurobiological changes detected when the stress switch from adaptable in everyday life to pathological leading to PTSD. Fear memories lead to the disruption of the anatomy/morphology of emotional-memory networks centered on the amygaloïd complex and hippocampal hub associated with the homeostatic unbalance of the body-brain exchanges of molecules such as hormones, neuromodulators or peptides. Persistent fear memories are hardly handled by the frontal ability for decision making towards action. But these fear memories can be revisited by different therapies recruiting cerebral plasticity and resilience. Current understanding of PTSD allowed to develop a series of efficient treatments associating precise medicine to diverse body-mind therapies.

Cannabidiol and the corticoraphe circuit in post-traumatic stress disorder

Post-Traumatic Stress Disorder (PTSD), characterized by re-experiencing, avoidance, negative affect, and impaired memory processing, may develop after traumatic events. PTSD is complicated by impaired plasticity and medial prefrontal cortex (mPFC) activity, hyperactivity of the amygdala, and impaired fear extinction. Cannabidiol (CBD) is a promising candidate for treatment due to its multimodal action that enhances plasticity and calms hyperexcitability. CBD’s mechanism in the mPFC of PTSD patients has been explored extensively, but literature on the mechanism in the dorsal raphe nucleus (DRN) is lacking. Following the PRISMA guidelines, we examined current literature regarding CBD in PTSD and overlapping symptomologies to propose a mechanism by which CBD treats PTSD via corticoraphe circuit. Acute CBD inhibits excess 5-HT release from DRN to amygdala and releases anandamide (AEA) onto amygdala inputs. By first reducing amygdala and DRN hyperactivity, CBD begins to ameliorate activity disparity between mPFC and amygdala. Chronic CBD recruits the mPFC, creating harmonious corticoraphe signaling. DRN releases enough 5-HT to ameliorate mPFC hypoactivity, while the mPFC continuously excites DRN 5-HT neurons via glutamate. Meanwhile, AEA regulates corticoraphe activity to stabilize signaling. AEA prevents DRN GABAergic interneurons from inhibiting 5-HT release so the DRN can assist the mPFC in overcoming its hypoactivity. DRN-mediated restoration of mPFC activity underlies CBD’s mechanism on fear extinction and learning of stress coping.

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CBD reduces PTSD symptoms via the DRN and corticoraphe circuit.

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Acute effects of CBD reduce DRN-amygdala excitatory signaling to lessen the activity disparity between amygdala and mPFC.

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Chronic CBD officially resolves mPFC hypoactivity by facilitating 5-HT release from DRN to mPFC.

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CBD-facilitated endocannabinoid signaling stabilizes DRN activity and restores mPFC inhibitory control.

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Chronically administered CBD acts via the corticoraphe circuit to favor fear extinction over fear memory reconsolidation.

Cannabidiol-based natural health products for companion animals: Recent advances in the management of anxiety, pain, and inflammation

Recent advances in cannabidiol (CBD) use in canines and felines for anxiety management, pain management, and anti-inflammatory effects were reviewed using a literature search conducted with the following keywords: CBD, anxiety, inflammation, pain, dogs, cats, and companion animals. For decades, research on CBD has been hindered due to the status of cannabis (C. sativa L.) as an illicit drug. Limited safety data show that CBD is well-tolerated in dogs, with insufficient information on the safety profile of CBD in cats. Upon oral supplementation of CBD, elevation in liver enzymes was observed for both dogs and cats, and pharmacokinetics of CBD are different in the two species. There is a significant gap in the literature on the therapeutic use of CBD in cats, with no feline data on anxiety, pain, and inflammation management. There is evidence that chronic osteoarthritic pain in dogs can be reduced by supplementation with CBD. Furthermore, experiments are required to better understand whether CBD has an influence on noise-induced fear and anxiolytic response. Preliminary evidence exists to support the analgesic properties of CBD in treating chronic canine osteoarthritis; however, there are inter- and intra-species differences in pharmacokinetics, tolerance, dosage, and safety of CBD. Therefore, to validate the anxiety management, pain management, and anti-inflammatory efficacy of CBD, it is essential to conduct systematic, randomized, and controlled trials. Further, the safety and efficacious dose of CBD in companion animals warrants investigation.

Cannabinoids, the endocannabinoid system, and pain: a review of preclinical studies

ABSTRACT

This narrative review represents an output from the International Association for the Study of Pain's global task force on the use of cannabis, cannabinoids, and cannabis-based medicines for pain management, informed by our companion systematic review and meta-analysis of preclinical studies in this area. Our aims in this review are (1) to describe the value of studying cannabinoids and endogenous cannabinoid (endocannabinoid) system modulators in preclinical/animal models of pain; (2) to discuss both pain-related efficacy and additional pain-relevant effects (adverse and beneficial) of cannabinoids and endocannabinoid system modulators as they pertain to animal models of pathological or injury-related persistent pain; and (3) to identify important directions for future research. In service of these goals, this review (1) provides an overview of the endocannabinoid system and the pharmacology of cannabinoids and endocannabinoid system modulators, with specific relevance to animal models of pathological or injury-related persistent pain; (2) describes pharmacokinetics of cannabinoids in rodents and humans; and (3) highlights differences and discrepancies between preclinical and clinical studies in this area. Preclinical (rodent) models have advanced our understanding of the underlying sites and mechanisms of action of cannabinoids and the endocannabinoid system in suppressing nociceptive signaling and behaviors. We conclude that substantial evidence from animal models supports the contention that cannabinoids and endocannabinoid system modulators hold considerable promise for analgesic drug development, although the challenge of translating this knowledge into clinically useful medicines is not to be underestimated.

Cannabidiol and Sertraline Regulate Behavioral and Brain Gene Expression Alterations in an Animal Model of PTSD

This study evaluated the effects of cannabidiol (CBD) and/or sertraline (STR) on behavioral and gene expression alterations induced by a new chronic animal model of post-traumatic stress disorder (PTSD). C57BL/6J male mice were repeatedly exposed to physical and psychogenic alternate stressful stimuli. Fear-related memory and anxiety-like behaviors were evaluated. The effects of the administration of CBD (20 mg/kg, i.p.) and/or STR (10 mg/kg, p.o.) were analyzed on behavioral and gene expression changes induced by the model of PTSD. Gene expression alterations of targets related with stress regulation, endocannabinoid and serotonergic systems were analyzed by real-time PCR. The results revealed an increased and long-lasting fear-related memory and anxiety-like behaviors in mice exposed to the animal model of PTSD. Treatment with CBD improved these behaviors in PTSD animals, effects that were significantly potentiated when combined with STR. Gene expression analyses revealed a long-term increase of corticotropin releasing factor (Crf) that was significantly normalized with the combination CBD plus STR. Cannabinoid receptors (Cnr1 and Cnr2) were up regulated in PTSD mice whereas the serotonin transporter (Slc6a4) was reduced. Interestingly, CBD and STR alone or combined induced a significant and marked increase of Slc6a4 gene expression. These results point out the cooperative action of the combination CBD plus STR to enhance fear extinction and reduce anxiety-like behaviors, normalizing gene expression alterations in this animal model of PTSD and suggesting that the combination of CBD with STR deserves to be further explored for the treatment of patients with PTSD.

Advances in the pharmacotherapeutic management of post-traumatic stress disorder

Introduction: Post-traumatic stress disorder (PTSD), a mental disorder, is associated with anxiety, depression, and social awkwardness resulting from past traumatic episodes like natural disasters, accidents, terrorist attacks, war, rape, and sexual violence. It affects primarily the amygdala, cortex, and hippocampus where neurochemical changes result in altered behavior. PTSD patients display impaired fear extinction, and past events keep haunting them. The topic presents relevant sections like PTSD pharmacotherapy, associated challenges, and the novel targets and drugs for future research and therapy.Areas covered: The authors discuss the current pharmacotherapy like SSRIs, NDRIs, SNRIs, anticonvulsants, antidepressants, and benzodiazepines, used to attenuate the associated symptoms. However, the primary focus being the novel and potential targets which can be explored better to understand possible future research and advanced therapy in PTSD. For the same, an account of both preclinical and clinical studies has been covered.Expert opinion: Excessive adverse effects, limited efficacy, and lower patient compliance are some of the major challenges with conventional drugs. Moreover, they correct only fewer symptoms without halting the disease progression. Several agents are investigated in different preclinical and clinical phases, which can potentially overcome the pitfalls and limitations associated with conventional therapies.

Fear extinction learning and anandamide: an fMRI study in healthy humans

Anxiety- and trauma-related disorders are severe illnesses with high prevalence. Current treatment options leave room for improvement and the endocannabinoid system (ECS) has become a key target in psychopharmacological research. Rodent models suggest an anxiolytic effect of endocannabinoids and demonstrated that the ECS is involved in the modulation of fear learning and aversive memory consolidation. So far, one prominent target was inhibition of fatty acid amino hydrolase (FAAH), the degrading enzyme of the endocannabinoid anandamide (AEA). Research in humans remains scarce, but genetic studies have found that the single-nucleotide polymorphism (SNP) FAAH C385A (rs324420) is associated with lower catabolic performance of FAAH and increased levels of AEA. Translational research on the ECS in fear learning processes is rare, yet crucial to understand the mechanisms involved. To address this lack of research, we designed a fear conditioning, extinction learning paradigm with 51 healthy, male humans who underwent functional magnetic resonance imaging (fMRI) before analysing baseline and task-related changes of AEA, as well as the FAAH polymorphism (rs324420). The results indicate higher AEA levels in AC-heterozygotes than in CC-individuals (SNP rs324420), but no difference between the groups during extinction learning. However, neural activation of the anterior cingulate cortex and anterior insular cortex during extinction learning correlated positively with AEA baseline levels, and task-related changes in AEA were found particularly during fear extinction, with a modulatory effect on neural activation related to extinction learning. Results indicate a putative role for AEA in fear extinction learning. Pre-treatment with AEA-enhancing drugs could promote extinction learning during psychotherapeutic interventions.

Endocannabinoid System as Therapeutic Target of PTSD: A Systematic Review

Post-Traumatic Stress Disorder (PTSD) is a complex disorder involving dysregulation of stress-related hormones and neurotransmitter systems. Research focused on the endocannabinoid system (eCBS) for anxiety and stress regulation, cognitive and emotional responses modulation and aversive memories extinction, leading to the hypothesis that it could represent a possible alternative treatment target for PTSD. In this systematic review, we summarize evidence about the efficacy and safety of medicinal cannabidiol (CBD), Δ⁹-tetrahydrocannabinol (Δ⁹-THC), and nabilone in PTSD treatment. The PRISMA statement guidelines were followed. A systematic literature search was conducted in MEDLINE/PubMed, Scopus and Web of Science by two independent researchers, who also performed data extraction and quality assessment. Among the initial 495 papers, 234 were screened for eligibility and 10 were included. Studies suggested that different medicinal cannabinoids at distinct doses and formulations could represent promising treatment strategies for the improvement of overall PTSD symptomatology as well as specific symptom domains (e.g., sleep disorders, arousal disturbances, suicidal thoughts), also influencing quality of life, pain and social impact. Although there is a robust rationale for treatment with drugs that target the eCBS and the results are promising, further studies are needed to investigate the safety and efficacy profile of their prolonged use.

miR-132 downregulation alleviates behavioral impairment of rats exposed to single prolonged stress, reduces the level of apoptosis in PFC, and upregulates the expression of MeCP2 and BDNF

Post-traumatic stress disorder (PTSD) is usually accompanied by anxiety symptoms and decreased expression of brain-derived neurotrophic factor (BDNF), which played an important role in promoting neuronal proliferation and survival. Methyl CpG-binding protein 2 (MeCP2) is a positive mediator of BDNF and is regulated by miR-132-3p. In the present study, we explored the possible molecular mechanism of miR-132, focusing on the involvement of MeCP2 and BDNF in the formation of anxiety-like symptoms of PTSD. Single prolonged stress (SPS) was used to establish a model of PTSD in adult rats and the anxiety-like behavior was tested by the elevated plus-maze (EPM). The level of miR-132 in the prefrontal cortex (PFC) was increased and intraventricular injection of anti-miR-132 could significantly improve the anxiety-like behavior of rats exposed to SPS through MeCP2 and the subsequent upregulation of BDNF levels. Then tropomyosin-related kinase B (TrkB) and downstream signals, including MAP kinase ERK1/2 and phosphoinositol 3-kinase (PI3K)/Akt pathways, were activated by BDNF upregulation, and might participate in regulating dendritic complexity and the expression of postsynaptic density-95 (PSD95) and synapsin I in the PFC of SPS rats. Furthermore, we found that the apoptosis of cells in PFC induced by SPS procedure could be alleviated by miR-132 inhibition. Our results suggest that miR-132 might be involved in the formation of anxiety-like symptoms of adult rat PTSD models by targeting MeCP2, and this effect is related to BDNF/TrkB and its downstream ERK and Akt signaling pathways.

From an Alternative Medicine to a New Treatment for Refractory Epilepsies: Can Cannabidiol Follow the Same Path to Treat Neuropsychiatric Disorders?

Although cannabis has been known for ages as an "alternative medicine" to provide relief from seizures, pain, anxiety, and inflammation, there had always been a limited scientific review to prove and establish its use in clinics. Early studies carried out by Carlini's group in Brazil suggested that cannabidiol (CBD), a non-psychotropic phytocannabinoid present in Cannabis sativa, has anticonvulsant properties in animal models and reduced seizure frequency in limited human trials. Over the past few years, the potential use of cannabis extract in refractory epilepsy, including childhood epilepsies such as Dravet's syndrome and Lennox-Gastaut Syndrome, has opened a new era of treating epileptic patients. Thus, a considerable number of pre-clinical and clinical studies have provided strong evidence that phytocannabinoids has anticonvulsant properties, as well as being promising in the treatment of different neuropsychiatric disorders, such as depression, anxiety, post-traumatic stress disorder (PTSD), addiction, neurodegenerative disorders and autism spectrum disorder (ASD). Given the advances of cannabinoids, especially CBD, in the treatment of epilepsy, would the same expectation regarding the treatment of other neuropsychiatric disorders be possible? The present review highlights some contributions from Brazilian researchers and other studies reported elsewhere on the history, pre-clinical and clinical data underlying the use of cannabinoids for the already widespread treatment of refractory epilepsies and the possibility of use in the treatment of some neuropsychiatric disorders.

Glial Cells and Their Contribution to the Mechanisms of Action of Cannabidiol in Neuropsychiatric Disorders

Cannabidiol (CBD) is a phytocannabinoid with a broad-range of therapeutic potential in several conditions, including neurological (epilepsy, neurodegenerative diseases, traumatic and ischemic brain injuries) and psychiatric disorders (schizophrenia, addiction, major depressive disorder, and anxiety). The pharmacological mechanisms responsible for these effects are still unclear, and more than 60 potential molecular targets have been described. Regarding neuropsychiatric disorders, most studies investigating these mechanisms have focused on neuronal cells. However, glial cells (astrocytes, oligodendrocytes, microglia) also play a crucial role in keeping the homeostasis of the central nervous system. Changes in glial functions have been associated with neuropathological conditions, including those for which CBD is proposed to be useful. Mostly in vitro studies have indicated that CBD modulate the activation of proinflammatory pathways, energy metabolism, calcium homeostasis, and the proliferative rate of glial cells. Likewise, some of the molecular targets proposed for CBD actions are f expressed in glial cells, including pharmacological receptors such as CB1, CB2, PPAR-γ, and 5-HT1A. In the present review, we discuss the currently available evidence suggesting that part of the CBD effects are mediated by interference with glial cell function. We also propose additional studies that need to be performed to unveil the contribution of glial cells to CBD effects in neuropsychiatric disorders.

Effects of Cannabinoids on Sleep and their Therapeutic Potential for Sleep Disorders

The recent trend for legalization of medicinal cannabis and cannabinoid-containing products, together with their soporific effects, has led to a surge of interest of their potential therapeutic role in the management of some common sleep disorders, such as insomnia, sleep disordered breathing, and restless legs syndrome, and less common disorders such as narcolepsy and parasomnias. Although much of the pre-clinical and clinical data were derived from studies with relatively small sample sizes and limited by biases in assessment, and in clinical trials lack of allocation concealment, as a whole, the results indicate a potential therapeutic role for cannabinoids in the management of some sleep disorders. Clinical trials are underway for insomnia and obstructive sleep apnea management, but there remains a substantial need for rigorous large multi-center studies to assess the dose, efficacy, and safety of the various types of cannabinoids on sleep disorders. This review aims to summarize the modulatory effects of cannabinoids on sleep physiology and provide a critical evaluation of the research on their potential therapeutic benefit in various sleep disorders.

Industrial Hemp (Cannabis sativa subsp. sativa) as an Emerging Source for Value-Added Functional Food Ingredients and Nutraceuticals

Industrial hemp (Cannabis sativa L., Cannabaceae) is an ancient cultivated plant originating from Central Asia and historically has been a multi-use crop valued for its fiber, food, and medicinal uses. Various oriental and Asian cultures kept records of its production and numerous uses. Due to the similarities between industrial hemp (fiber and grain) and the narcotic/medical type of Cannabis, the production of industrial hemp was prohibited in most countries, wiping out centuries of learning and genetic resources. In the past two decades, most countries have legalized industrial hemp production, prompting a significant amount of research on the health benefits of hemp and hemp products. Current research is yet to verify the various health claims of the numerous commercially available hemp products. Hence, this review aims to compile recent advances in the science of industrial hemp, with respect to its use as value-added functional food ingredients/nutraceuticals and health benefits, while also highlighting gaps in our current knowledge and avenues of future research on this high-value multi-use plant for the global food chain.

The effects of acute cannabidiol on cerebral blood flow and its relationship to memory: An arterial spin labelling magnetic resonance imaging study

BACKGROUND

Cannabidiol (CBD) is being investigated as a potential treatment for several medical indications, many of which are characterised by altered memory processing. However, the mechanisms underlying these effects are unclear.

AIMS

Our primary aim was to investigate how CBD influences cerebral blood flow (CBF) in regions involved in memory processing. Our secondary aim was to determine if the effects of CBD on CBF were associated with differences in working and episodic memory task performance.

METHODS

We used a randomised, crossover, double-blind design in which 15 healthy participants were administered 600 mg oral CBD or placebo on separate days. We measured regional CBF at rest using arterial spin labelling 3 h after drug ingestion. We assessed working memory with the digit span (forward, backward) and n-back (0-back, 1-back, 2-back) tasks, and we used a prose recall task (immediate and delayed) to assess episodic memory.

RESULTS

CBD increased CBF in the hippocampus (mean (95% confidence intervals) = 15.00 (5.78-24.21) mL/100 g/min, t₁₄ = 3.489, Cohen's d = 0.75, p = 0.004). There were no differences in memory task performance, but there was a significant correlation whereby greater CBD-induced increases in orbitofrontal CBF were associated with reduced reaction time on the 2-back working memory task ( r= -0.73, p = 0.005).

CONCLUSIONS

These findings suggest that CBD increases CBF to key regions involved in memory processing, particularly the hippocampus. These results identify potential mechanisms of CBD for a range of conditions associated with altered memory processing, including Alzheimer's disease, schizophrenia, post-traumatic stress disorder and cannabis-use disorders.

Effects of Chronic Cannabidiol Treatment in the Rat Chronic Unpredictable Mild Stress Model of Depression

Several neuropharmacological actions of cannabidiol (CBD) due to the modulation of the endocannabinoid system as well as direct serotonergic and gamma-aminobutyric acidergic actions have recently been identified. The current study aimed to reveal the effect of a long-term CBD treatment in the chronic unpredictable mild stress (CUMS) model of depression. Adult male Wistar rats (n = 24) were exposed to various stressors on a daily basis in order to induce anhedonia and anxiety-like behaviors. CBD (10 mg/kg body weight) was administered by daily intraperitoneal injections for 28 days (n = 12). The effects of the treatment were assessed on body weight, sucrose preference, and exploratory and anxiety-related behavior in the open field (OF) and elevated plus maze (EPM) tests. Hair corticosterone was also assayed by liquid chromatography-mass spectrometry. At the end of the experiment, CBD-treated rats showed a higher rate of body weight gain (5.94% vs. 0.67%) and sucrose preference compared to controls. A significant increase in vertical exploration and a trend of increase in distance traveled in the OF test were observed in the CBD-treated group compared to the vehicle-treated group. The EPM test did not reveal any differences between the groups. Hair corticosterone levels increased in the CBD-treated group, while they decreased in controls compared to baseline (+36.01% vs. -45.91%). In conclusion, CBD exerted a prohedonic effect in rats subjected to CUMS, demonstrated by the increased sucrose preference after three weeks of treatment. The reversal of the effect of CUMS on hair corticosterone concentrations might also point toward an anxiolytic or antidepressant-like effect of CBD, but this needs further confirmation.

The role of catecholamines in modulating responses to stress: Sex-specific patterns, implications, and therapeutic potential for post-traumatic stress disorder and opiate withdrawal

Emotional arousal is one of several factors that determine the strength of a memory and how efficiently it may be retrieved. The systems at play are multifaceted; on one hand, the dopaminergic mesocorticolimbic system evaluates the rewarding or reinforcing potential of a stimulus, while on the other, the noradrenergic stress response system evaluates the risk of threat, commanding attention, and engaging emotional and physical behavioral responses. Sex-specific patterns in the anatomy and function of the arousal system suggest that sexually divergent therapeutic approaches may be advantageous for neurological disorders involving arousal, learning, and memory. From the lens of the triple network model of psychopathology, we argue that post-traumatic stress disorder and opiate substance use disorder arise from maladaptive learning responses that are perpetuated by hyperarousal of the salience network. We present evidence that catecholamine-modulated learning and stress-responsive circuitry exerts substantial influence over the salience network and its dysfunction in stress-related psychiatric disorders, and between the sexes. We discuss the therapeutic potential of targeting the endogenous cannabinoid system; a ubiquitous neuromodulator that influences learning, memory, and responsivity to stress by influencing catecholamine, excitatory, and inhibitory synaptic transmission. Relevant preclinical data in male and female rodents are integrated with clinical data in men and women in an effort to understand how ideal treatment modalities between the sexes may be different.

Developmental differences in the effects of CB1/2R agonist WIN55212-2 on extinction of learned fear

Adolescence is characterised by substantial changes in emotion regulation and, in particular, impaired extinction consolidation and retention. In this study, we replicated the well-established finding that increasing the activation of cannabinoid receptor 1 (CB1R) via the agonist WIN55212-2 improves fear extinction in adult rodents before examining whether this adjunct would also rescue the extinction retention deficit seen in adolescent rodents. Contrary to the effects in adults, we found that WIN55212-2 impaired within-session acquisition of extinction in adolescent rats with no effect on extinction retention. The same effects of WIN55212-2 were observed for juvenile rats, and did not vary as a function of drug dose. Increased fear expression observed during extinction training was not a result of altered locomotor or anxiety-like behaviour in adolescent rats, as assessed by the open field test. Lastly, we observed a linear decrease in CB1R protein expression across age (i.e., from juveniles, to adolescents, and adults) in both the medial prefrontal cortex and amygdala, two regions implicated in fear expression and extinction, suggesting that there is continued refinement of the endocannabinoid system across development in two regions involved in extinction. Our findings suggest that the expression and extinction of fear in developing rats is differentially affected by CB1R agonism due to an immature endocannabinoid system.

Cannabinoids as therapeutics for PTSD

Post-traumatic stress disorder (PTSD) is a complex disorder that involves dysregulation of multiple neurobiological systems. The traumatic stressor plays a causal role in producing psychological dysfunction and the pattern of findings suggests that the hypothalamic-pituitary-adrenal (HPA) axis, which is instrumental for stress adaptation, is critically dysfunctional in PTSD. Given the lack of understanding of the basic mechanisms and underlying pathways that cause the disorder and its heterogeneity, PTSD poses challenges for treatment. Targeting the endocannabinoid (ECB) system to treat mental disorders, and PTSD in particular, has been the focus of research and interest in recent years. The ECB system modulates multiple functions, and drugs enhancing ECB signaling have shown promise as potential therapeutic agents in stress effects and other psychiatric and medical conditions. In this review, we focus on the interaction between the ECB-HPA systems in animal models for PTSD and in patients with PTSD. We summarize evidence supporting the use of cannabinoids in preventing and treating PTSD in preclinical and clinical studies. As the HPA system plays a key role in the mediation of the stress response and the pathophysiology of PTSD, we describe preclinical studies suggesting that enhancing ECB signaling is consistent with decreasing PTSD symptoms and dysfunction of the HPA axis. Overall, we suggest that a pharmacological treatment targeted at one system (e.g., HPA) may not be very effective because of the heterogeneity of the disorder. There are abnormalities across different neurotransmitter systems in the pathophysiology of PTSD and none of these systems function uniformly among all patients with PTSD. Hence, conceptually, enhancing ECB signaling may be a more effective avenue for pharmacological treatment.

Cannabidiol-from Plant to Human Body: A Promising Bioactive Molecule with Multi-Target Effects in Cancer

Cannabis sativa L. is a plant long used for its textile fibers, seed oil, and oleoresin with medicinal and psychoactive properties. It is the main source of phytocannabinoids, with over 100 compounds detected so far. In recent years, a lot of attention has been given to the main phytochemicals present in Cannabis sativa L., namely, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC). Compared to THC, CBD has non-psychoactive effects, an advantage for clinical applications of anti-tumor benefits. The review is designed to provide an update regarding the multi-target effects of CBD in different types of cancer. The main focus is on the latest in vitro and in vivo studies that present data regarding the anti-proliferative, pro-apoptotic, cytotoxic, anti-invasive, anti-antiangiogenic, anti-inflammatory, and immunomodulatory properties of CBD together with their mechanisms of action. The latest clinical evidence of the anticancer effects of CBD is also outlined. Moreover, the main aspects of the pharmacological and toxicological profiles are given.

Translating Molecular and Neuroendocrine Findings in Posttraumatic Stress Disorder and Resilience to Novel Therapies

Many biological systems are altered in association with posttraumatic stress disorder (PTSD) and resilience. However, there are only few approved pharmacological treatments for PTSD, and no approved medications to enhance resilience. This article provides a critical review of select neurobiological findings in PTSD and resilience, and also of pharmacologic approaches that have emerged from this work. The medications summarized involve engagement with targets in the adrenergic, hypothalamic-pituitary-adrenal axis, and neuropeptide Y systems. Other highlighted approaches involve the use of ketamine and 3,4-methylenedioxymethamphetamine-assisted psychotherapy, which recently surfaced as promising strategies for PTSD, though the neurobiological mechanisms underlying their actions, including for promoting resilience, are not yet fully understood. The former approaches fall within the broad concept of "rational pharmacotherapy," in that they attempt to directly target dysregulated systems known to be associated with posttraumatic symptoms. To the extent that use of ketamine and 3,4-methylenedioxymethamphetamine promotes symptom improvement and resilience in PTSD, this provides an opportunity for reverse translation and identification of relevant targets and mechanisms of action through careful study of biological changes resulting from these interventions. Promoting resilience in trauma-exposed individuals may involve more than pharmacologically manipulating dysregulated molecules and pathways associated with developing and sustaining PTSD symptom severity, but also producing a substantial change in mental state that increases the ability to engage with traumatic material in psychotherapy. Neurobiological examination in the context of treatment studies may yield novel targets and promote a greater understanding of mechanisms of recovery from trauma.

Use of Medicinal Cannabis and Synthetic Cannabinoids in Post-Traumatic Stress Disorder (PTSD): A Systematic Review

Background and Objectives: Post-traumatic stress disorder (PTSD) is a common psychiatric disorder resulting from a traumatic event, is manifested through hyperarousal, anxiety, depressive symptoms, and sleep disturbances. Despite several therapeutic approaches being available, both pharmacological and psychological, recently a growing interest has developed in using cannabis and synthetic cannabinoids stems from their consideration as more efficient and better tolerated alternatives for the treatment of this condition. The present paper aims to evaluate the clinical and therapeutic potentials of medical cannabis and synthetic cannabinoids in treating PTSD patients. Methods: A systematic electronic search was performed, including all papers published up to May 2019, using the following keywords (((cannabis[Title/Abstract]) OR (synthetic cannabinoids [Title/Abstract])) AND ((PTSD[Title/Abstract]) OR (Posttraumatic stress disorder[Title/Abstract]))) for the topics ‘Cannabis’, ‘Synthetic Cannabinoids’, ‘PTSD’, and MESH terms, on the PubMed, Cochrane Library, and Web of Science online databases. For data gathering purposes, PRISMA guidelines were followed. Results were organized into two groups, considering cannabis and synthetic cannabinoids as different therapeutic approaches for PTSD. Results: Present data show that cannabis and synthetic cannabinoids, both acting on the endocannabinoids system, may have a potential therapeutic use for improving PTSD symptoms, e.g., reducing anxiety, modulating memory-related processes, and improving sleep. Conclusions: Even though the current literature suggests that cannabis and synthetic cannabinoids may have a role in the treatment of PTSD, there is currently limited evidence regarding their safety and efficacy. Therefore, additional research is needed in order to better understand the effectiveness and therapeutic usage of these drug classes and monitor their safety.

Cannabidiol (CBD) use in psychiatric disorders: A systematic review

Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) are the most represented phytocannabinoids in Cannabis sativa plants. However, CBD may present with a different activity compared with the psychotomimetic THC. Most typically, CBD is reported to be used in some medical conditions, including chronic pain. Conversely, the main aim of this systematic review is to assess and summarise the available body of evidence relating to both efficacy and safety of CBD as a treatment for psychiatric disorders, alone and/or in combination with other treatments. Eligible studies included randomized controlled trials (RCT) assessing the effect of CBD in a range of psychopathological conditions, such as substance use; psychosis, anxiety, mood disturbances, and other psychiatric (e.g., cognitive impairment; sleep; personality; eating; obsessive-compulsive; post-traumatic stress/PTSD; dissociative; and somatic) disorders. For data gathering purposes, the PRISMA guidelines were followed. The initial search strategy identified some n = 1301 papers; n = 190 studies were included after the abstract's screening and n = 27 articles met the inclusion criteria. There is currently limited evidence regarding the safety and efficacy of CBD for the treatment of psychiatric disorders. However, available trials reported potential therapeutic effects for specific psychopathological conditions, such as substance use disorders, chronic psychosis, and anxiety. Further large-scale RCTs are required to better evaluate the efficacy of CBD in both acute and chronic illnesses, special categories, as well as to exclude any possible abuse liability.