Endocannabinoid System and Exogenous Cannabinoids in Depression and Anxiety: A Review

Co-treatment with cannabidiol and escitalopram in ineffective doses induces antidepressant effect in maternally separated male adolescent rats

Due to low efficacy and delayed therapeutic effect of drugs currently used in the therapy of depression in adolescent population, a lot of effort has been put into finding new substances using alternative target points that could support treatment with traditional antidepressive drugs. Cannabidiol, compound derived from Cannabis sativa may have therapeutic potential in depressive disorders. This study aimed to investigate whether combined administration of escitalopram with cannabidiol in ineffective doses, will provide better or similar effects in behavioral tests compared to escitalopram in an effective dose in adolescent maternally separated rats. Maternal separation has been used as a form of early life adversity. The pups were separated from their dams for 360 min daily from postnatal day (PND) 2 until PND 15. Later, escitalopram (15 or 5 mg/kg) or vehicle were administered ip. in a subacute manner in mid-adolescent male rats. Cannabidiol (15 mg/kg) or vehicle were injected ip. in a single dose about 1 h prior to behavioral assessment. Three standard behavioral tests were performed: the elevated plus maze and the open field test on PND 42 and the forced swimming test on PND 43-44 on the subsequent groups of rats. The combined treatment with escitalopram and cannabidiol in ineffective doses did not induce anxiolytic-like effects but successfully relieved despair behavior in the forced swimming test showing similar efficacy as treatment with escitalopram in effective dose. This result might be the basis for future research and the development of new therapeutic strategies for treatment of adolescent depression.

Phytocannabinoids restore seizure-induced alterations in emotional behaviour in male rats

Epilepsy often presents with severe emotional comorbidities including anxiety and abnormal fear responses which impose a significant burden on, and reduce, quality of life in people living with the disease. Our lab has recently shown that kindled seizures lead to changes in emotional processing resulting from the downregulation of anandamide signalling within the amygdala. Phytocannabinoids derived from the Cannabis sativa plant have attracted a lot of interest as a new class of drugs with potential anticonvulsant effects. Among the wide number of compounds occurring in Cannabis sativa, Δ9- tetrahydrocannabinol (THC), the one responsible for its main psychoactive effects, and the nonpsychoactive cannabidiol (CBD) have been extensively examined under pre-clinical and clinical contexts to control seizures, however, neither have been assessed in the context of the management of emotional comorbidities associated with seizure activity. We used two behavioural procedures to assess anxiety- and fear-like responding in adult male Long-Evans rats: elevated plus maze and auditory fear conditioning. In agreement with previous reports, we found seizure-induced increases in anxiety- and fear-like responding. These effects were reversed by either CBD (vaporized) or THC (oral). We also found that antagonism of serotonin 1 A receptors prior to CBD exposure prevented its protective effects. Phytocannabinoids offer a novel and reliable opportunity to treat seizure induced comorbid emotional alterations.

The role of cannabinoid-mediated signaling pathways and mechanisms in brain disorders

Cannabinoids play significant roles in the central nervous system (CNS), but cannabinoid-mediated physiopathological functions are not elaborated. Cannabinoid receptors (CBRs) mediate functions that include the regulation of neuroinflammation, oxidative stress, apoptosis, autophagy, and neurogenesis. Microglia are the primary immune cells responsible for mediating neuroinflammation in the CNS. Therefore, this article primarily focuses on microglia to summarize the inflammatory pathways mediated by cannabinoids in the CNS, including nuclear factor-κB (NF-κB), NOD-like receptor protein 3 (NLRP3) inflammasome, mitogen-activated protein kinase (MAPK), protein kinase B (Akt), and cAMP-dependent protein kinase (PKA) signaling pathways. Additionally, we provide a table summarizing the role of cannabinoids in various brain diseases. Medical use of cannabinoids has protective effects in preventing and treating brain diseases; however, excessive and repeated use can be detrimental to the CNS. We propose that cannabinoids hold significant potential for preventing and treating brain diseases, including ferroptosis, lactate metabolism, and mitophagy, providing new insights for further research on cannabinoids.

Cannabis use and sleep problems among young adults by mental health status: A prospective cohort study

BACKGROUND AND AIMS

Young adult cannabis use is common; while cannabis is often marketed as a product that can improve sleep, evidence supporting these claims is limited, and effects may differ for individuals with underlying mental health issues. This study measured the association between cannabis use and sleep problems among young adults and determined whether associations differ by mental health status.

DESIGN, SETTING AND PARTICIPANTS

Using two waves of a young adult cohort study (baseline: March-September 2020; follow-up: January-June 2021), we measured the association of cannabis use frequency with subsequent sleep problems overall and stratified by baseline sleep quality and mental health status in separate moderation analyses. This study was conducted in Southern California, USA, and included 1926 participants aged 20-23 years (mean age = 21; 61% female, 46% Hispanic).

MEASUREMENTS

Exposure was baseline cannabis use frequency (never use, prior use, 1-5 days/month, 6-19 days/month, ≥ 20 days/month). The outcome was sleep problems at follow-up (range = 4-24, higher score indicating worse sleep). Models were adjusted for socio-demographic factors, baseline sleep problems, mental health symptoms (depression and/or anxiety versus neither) and past 30-day nicotine or alcohol use. In moderation analyses, models were additionally stratified by mental health symptoms and baseline sleep quality (excellent versus imperfect sleep).

FINDINGS

Among the young adult sample, 11% used cannabis ≥ 20 days/month at baseline. For participants without baseline anxiety or depression symptoms, using cannabis ≥ 20 days/month (versus never use) was associated with greater sleep problems at follow-up [mean difference (MD) = 1.66, 95% confidence interval (CI) = 0.59-2.74]. Among participants with anxiety and/or depression and pre-existing sleep problems at baseline, using cannabis ≥ 20 days/month (versus never use) was associated with fewer sleep problems at follow-up (MD = -1.42, 95% CI = -2.81 to -0.02).

CONCLUSIONS

The effects of cannabis use on sleep appear to differ by underlying mental health symptoms. Frequent cannabis use may improve sleep for young adults with depression and/or anxiety who have pre-existing sleep problems, but worsen sleep for young adults without depression and/or anxiety.

Early oral administration of THC:CBD formulations prevent pain-related behaviors without exacerbating paclitaxel-induced changes in weight, locomotion, and anxiety in a rat model of chemotherapy-induced neuropathy

RATIONALE

Paclitaxel-induced neuropathy stands out as the primary, dose-limiting side effect of this extensively used chemotherapy agent. Prolonged hypersensitivity and pain represent the most severe clinical manifestations. Effective preventive and therapeutic strategies are currently lacking.

OBJECTIVES

Our study aimed to assess the impact of early oral administration of pharmaceutical-grade formulations containing the phytocannabinoids THC and CBD in a rat model of paclitaxel-induced neuropathy.

METHODS

The experimental design involved the co-administration of paclitaxel and cannabinoid formulations with different THC to CBD ratios (THC:CBD 1:1 and THC:CBD 1:20) to adult male rats. Mechanical and thermal sensitivity, locomotor activity, vertical exploratory behaviors, anxiety-related parameters, weight gain, food and water consumption, and liver functionality were assessed.

RESULTS

Daily administration of THC:CBD 1:1 successfully prevented paclitaxel-induced cold allodynia, while THC:CBD 1:20 effectively prevented both thermal and mechanical hypersensitivities. Additionally, THC:CBD 1:1 formulation restored rearing behavior, significantly reduced by paclitaxel. Conversely, neither cannabinoid formulation was able to counteract paclitaxel-induced hypo-locomotion, reduced vertical exploratory activity, increased anxiety-like behaviors, attenuated weight gain, or decreased food and water intakes. However, the formulations employed did not induce further alterations or toxicity in animals receiving paclitaxel, and no signs of liver damage were detected.

CONCLUSIONS

Our results suggest a differential therapeutic effect of two THC:CBD formulations on pain-related behaviors and spontaneous activities, particularly in the context of peripheral neuropathy. These formulations represent a promising therapeutic strategy not only to managing pain but also for enhancing daily activities and improving the quality of life for cancer patients.

Advances in cannabinoid receptors pharmacology: from receptor structural insights to ligand discovery

The medicinal and recreational uses of Cannabis sativa have been recognized for thousands of years. Today, cannabis-derived medicines are used to treat a variety of conditions, including chronic pain, epilepsy, multiple sclerosis, and chemotherapy-induced nausea. However, cannabis use disorder (CUD) has become the third most prevalent substance use disorder globally. Cannabinoid receptors are the primary targets that mediate the effects of cannabis and its analogs. Despite their importance, the mechanisms of modulation and the full therapeutic potential of cannabinoid receptors remain unclear, hindering the development of the next generation of cannabinoid-based drugs. This review summarizes the discovery and medicinal potential of phytocannabinoids and explores the distribution, signaling pathways, and functional roles of cannabinoid receptors. It also discusses classical cannabinoid drugs, as well as agonists, antagonists, and inverse agonists, which serve as key therapeutic agents. Recent advancements in the development of allosteric drugs are highlighted, with a focus on positive and negative allosteric modulators (PAMs and NAMs) that target CB1 and CB2 receptors. The identification of multiple allosteric sites on the CB1 receptor and the structural basis for allosteric modulation are emphasized, along with the structure-based discovery of ago-BAMs for CB1. This review concludes by examining the future potential of allosteric modulators in cannabinoid drug development, noting that ongoing progress in cannabinoid-derived drugs continues to open new avenues for therapeutic use and paves the way for future research into their full medicinal potential.

Gastrodin Ameliorates Post-Stroke Depressive-Like Behaviors Through Cannabinoid-1 Receptor-Dependent PKA/RhoA Signaling Pathway

Post-stroke depression (PSD) is a significant complication in stroke patients, increases long-term mortality, and exaggerates ischemia-induced brain injury. However, the underlying molecular mechanisms and effective therapeutic targets related to PSD have remained elusive. Here, we employed an animal behavioral model of PSD by combining the use of middle cerebral artery occlusion (MCAO) followed by spatial restraint stress to study the molecular underpinnings and potential therapies of PSD. Interestingly, we found that sub-chronic application of gastrodin (Gas), a traditional Chinese medicinal herb Gastrodia elata extraction, relieved depression-related behavioral deficits, increased the impaired expression of synaptic transmission-associated proteins, and restored the altered spine density in hippocampal CA1 of PSD animals. Furthermore, our results indicated that the anti-PSD effect of Gas was dependent on membrane cannabinoid-1 receptor (CB1R) expression. The contents of phosphorated protein kinase A (p-PKA) and phosphorated Ras homolog gene family member A (p(ser188)-RhoA) were decreased in the hippocampus of PSD-mice, which was reversed by Gas treatment, and CB1R depletion caused a diminished efficacy of Gas on p-PKA and p-RhoA expression. In addition, the anti-PSD effect of Gas was partially blocked by PKA inhibition or RhoA activation, indicating that the anti-PSD effect of Gas is associated with the CB1R-mediated PKA/RhoA signaling pathway. Together, our findings revealed that Gas treatment possesses protective effects against the post-stroke depressive-like state; the CB1R-involved PKA/RhoA signaling pathway is critical in mediating Gas's anti-PSD potency, suggesting that Gas application may be beneficial in the prevention and adjunctive treatment of PSD.

Cannabinoids and the male reproductive system: Implications of endocannabinoid signaling pathways

The escalating use and legalization of cannabis (marijuana) in the United States reflect shifting societal attitudes and growing awareness of its potential therapeutic benefits. Historically viewed as a harmful psychoactive substance, contemporary research has shown the intricate pharmacology of cannabis, with its diverse array of cannabinoids and their interactions with the endocannabinoid system. Among these cannabinoids, Δ9-tetrahydrocannabinol is the primary psychoactive component, characterized by its activation of cannabinoid receptors. The discovery of endocannabinoids, including anandamide and 2-arachidonoylglycerol, illuminated the body's innate cannabinoid signaling pathways and their involvement in several physiological processes. Endocannabinoids exert both positive and negative effects on the male reproductive system. They facilitate erectile function by modulating neurotransmission and vasodilation, offering potential therapeutic avenues for conditions like erectile dysfunction and prostatitis. However, chronic exogenous cannabinoid use, mainly of tetrahydrocannabinol, poses risks to male reproductive health by disrupting spermatogenesis, causing hormonal imbalances, and potentially influencing cancer cell proliferation. Understanding endocannabinoid signaling in the male reproductive system is essential to fully comprehend both the therapeutic benefits and potential drawbacks of cannabis use. Further research is required on these mechanisms, to provide insights that can guide clinical practice and policy-making regarding cannabis use. In this narrative review, we highlight the need for additional research into how cannabinoids affect male reproductive health, particularly with prolonged use. Investigating cannabinoids' impacts on spermatogenesis, hormonal balance, and cancer cell proliferation can provide valuable insights for healthcare professionals.

Genome-wide meta-analyses of non-response to antidepressants identify novel loci and potential drugs

Antidepressants exhibit a considerable variation in efficacy, and increasing evidence suggests that individual genetics contribute to antidepressant treatment response. Here, we combined data on antidepressant non-response measured using rating scales for depressive symptoms, questionnaires of treatment effect, and data from electronic health records, to increase statistical power to detect genomic loci associated with non-response to antidepressants in a total sample of 135,471 individuals prescribed antidepressants (25,255 non-responders and 110,216 responders). We performed genome-wide association meta-analyses, genetic correlation analyses, leave-one-out polygenic prediction, and bioinformatics analyses for genetically informed drug prioritization. We identified two novel loci (rs1106260 and rs60847828) associated with non-response to antidepressants and showed significant polygenic prediction in independent samples. Genetic correlation analyses show positive associations between non-response to antidepressants and most psychiatric traits, and negative associations with cognitive traits and subjective well-being. In addition, we investigated drugs that target proteins likely involved in mechanisms underlying antidepressant non-response, and shortlisted drugs that warrant further replication and validation of their potential to reduce depressive symptoms in individuals who do not respond to first-line antidepressant medications. These results suggest that meta-analyses of GWAS utilizing real-world measures of treatment outcomes can increase sample sizes to improve the discovery of variants associated with non-response to antidepressants.

UK Medical Cannabis Registry: a cohort study of patients prescribed cannabis-based oils and dried flower for generalised anxiety disorder

BACKGROUND

Generalized anxiety disorder (GAD) is a common mental health condition. The endocannabinoid system has become a focus for new therapies, increasing interest in cannabis-based medicinal products (CBMPs). This study uses data from the UK Medical Cannabis Registry (UKMCR) to investigate real-world outcomes and safety of different CBMP formulations in GAD patients.

METHODS

This study analyzed patient-reported outcomes from 302 GAD patients prescribed CBMPs (oil-based, dried flower, or a combination). Anxiety (GAD-7), sleep quality (SQS), and quality of life (EQ-5D-5 L) were assessed at 1, 3, 6, and 12 months. Adverse events were recorded.

RESULTS

All CBMP formulations were associated with improvements in anxiety, sleep, and quality of life over 12 months (p < 0.050). At 12 months, there were no significant differences in outcomes between formulations (p > 0.050). The majority of reported adverse events (n = 707) were mild (n = 343) or moderate (n = 285) in severity, with no life-threatening events observed.

CONCLUSION

This study provides real-world evidence supporting the potential of CBMPs for improving GAD symptoms. Patients prescribed both oil-based and dried flower formulations have similar outcomes over 12 months. Further research is needed to determine the optimal CBMP formulation and long-term effects.

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.

Endocannabinoid System and Metabolism: The Influences of Sex

The endocannabinoid system (ECS) is a lipid signaling system involved in numerous physiological processes, such as endocrine homeostasis, appetite control, energy balance, and metabolism. The ECS comprises endocannabinoids, their cognate receptors, and the enzymatic machinery that tightly regulates their levels within tissues. This system has been identified in various organs, including the brain and liver, in multiple mammalian and non-mammalian species. However, information regarding the sex-specific regulation of the ECS remains limited, even though increasing evidence suggests that interactions between sex steroid hormones and the ECS may ultimately modulate hepatic metabolism and energy homeostasis. Within this framework, we will review the sexual dimorphism of the ECS in various animal models, providing evidence of the crosstalk between endocannabinoids and sex hormones via different metabolic pathways. Additionally, we will underscore the importance of understanding how endocrine-disrupting chemicals and exogenous cannabinoids influence ECS-dependent metabolic pathways in a sex-specific manner.

Association between cannabis use and physical activity in the United States based on legalization and health status

BACKGROUND

Studies investigating the association between cannabis use and physical activity have had mixed results. This study provided a population-based assessment while determining how the relationship is affected by variables such as cannabis legalization status and chronic medical conditions.

METHODS

Behavior Risk Factor Surveillance System (BRFSS) data were used to evaluate the association between cannabis use and physical activity among adults ages 18 years and older in several states and territories of the U.S. during 2016-2022. Adjusted odds ratios (ORs) measuring the relationship between physical activity in the past 30 days (yes vs. no) and cannabis use in the past 30 days (yes vs. no) based on legalization and health status were estimated using logistic regression.

RESULTS

Physical activity increased from 73.16% in 2016 to 75.72% in 2022 (3.5% increase) and current cannabis use increased from 7.48% in 2016 to 14.71% in 2022 (96.7% increase). Current cannabis use was 6.5% higher in areas of legalized recreational cannabis (vs. not legal) and 0.7% higher in areas of legalized medical cannabis (vs. not legal). For the combined years, the OR measuring the association between cannabis use and physical activity was 1.24 (95% CI 1.10-1.41), after adjusting for age, sex, race/ethnicity, marital status, employment status, education, smoking status, weight classification, legal status, and chronic medical condition. The adjusted OR was 1.47 (95% CI 1.34-1.62) in areas with legalized recreational and medical cannabis (vs. illegal) and 1.05 (95% CI 0.98-1.12) in areas with legalized medical cannabis only (vs. illegal). Having a medical condition was significantly associated with lower prevalence of physical activity in the adjusted models (overall adjusted OR = 0.79, 95% CI 0.73-0.85). However, this significantly lower odds ratio was insignificant for current cannabis users.

CONCLUSIONS

Public policy and personal health behaviors may improve with the findings that legal medical cannabis promotes greater physical activity in those experiencing chronic medical conditions and legal recreational cannabis promotes (even more so) greater physical activity in those not experiencing chronic medical conditions.

The Interplay of Exogenous Cannabinoid Use on Anandamide and 2-Arachidonoylglycerol in Anxiety: Results from a Quasi-Experimental Ad Libitum Study

The public is increasingly reporting using cannabis for anxiety relief. Both cannabis use and the endocannabinoid system have been connected with anxiety relief/anxiolytic properties, but these relationships are complex, and the underlying mechanisms for them are unclear. Background/Objectives: Work is needed to understand how the endocannabinoid system, including the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG), may be impacted by the main constituents of cannabis, Δ9-tetrahydrocannabinol (THC), and cannabidiol (CBD). Methods: The current study examined how the ab libitum use of products differing in THC and CBD affected AEA and 2-AG among 292 individuals randomly assigned to THC-dominant use (N = 92), CBD-dominant use (N = 97), THC + CBD use (N = 74), or non-use (N = 29). Results: The findings suggest that AEA levels do not change differently based on 4 weeks of cannabis use or by cannabinoid content, as AEA similarly increased across all conditions from study weeks 2 to 4. In contrast, AEA decreased at an acute administration session with product conditions containing any THC having greater AEA levels on average than the non-use condition. With regard to 2-AG, its levels appeared to primarily be affected by THC-dominant use, both acutely and over 4 weeks, when controlling for baseline cannabis use and examining study product use frequency among use conditions. Conclusions: Overall, the results continue to shed light on the complicated relationship between cannabinoid content and endocannabinoid production, and highlight the need for continued research on their interplay in human subjects.

CBD-Loaded Nanostructured Lipid Carriers: Optimization, Characterization, and Stability

Cannabidiol (CBD) has demonstrated its potential to enhance depression treatment through various biological pathways. However, the application potential of CBD is significantly impeded by its polymorphic nature, limited water solubility, and hepatic first-pass metabolism. To improve chemical stability and water solubility, nanostructured lipid carriers loaded with CBD (CBD-NLCs) were developed using a hot-melt emulsification method and optimized by response surface methodology (RSM). The process parameters were optimized using a four-factor and three-level Box-Behnken experimental design consisting of 29 experiments. The CBD-NLCs were formulated and characterized, demonstrating desirable properties, including a mean particle size of 54.33 nm, a PDI value of 0.118, a zeta potential of -29.7 mV, and an impressive encapsulation efficiency rate of 87.58%. The nanoparticles were found to possess an approximately spherical shape, as revealed by scanning and transmission electron microscopy. The stability studies have demonstrated that CBD-NLCs effectively mitigated the photodegradation of CBD and exhibited a stable behavior for 42 days when stored. The CBD-NLCs displayed a biphasic release profile characterized by an initial burst release (over 50% of CBD released within 20 min) followed by a subsequent gradual and sustained release, aligned with first-order kinetics and Fickian diffusion. These findings demonstrate the potential suitability of this formulation as a carrier for CBD in food fortification and pharmaceutical applications.

Role of T and B lymphocyte cannabinoid type 1 and 2 receptors in major depression and suicidal behaviours

Early flow cytometry studies revealed T cell activation in major depressive disorder (MDD). MDD is characterised by activation of the immune-inflammatory response system (IRS) and the compensatory immunoregulatory system (CIRS), including deficits in T regulatory (Treg) cells. This study examines the number of cannabinoid type 1 (CB1) and type 2 (CB2) receptor-bearing T/B lymphocytes in MDD, and the effects of in vitro cannabidiol (CBD) administration on CB1/CB2-bearing immunocytes. Using flow cytometry, we determined the percentage of CD20+CB2+, CD3+CB2+, CD4+CB2+, CD8+CB2+ and FoxP3+CB1+ cells in 19 healthy controls and 29 MDD patients in 5 conditions: baseline, stimulation with anti-CD3/CD28 with or without 0.1 µg/mL, 1.0 µg/mL, or 10.0 µg/mL CBD. CB2+ was significantly higher in CD20+ than CD3+ and CD4+ and CD 8+ cells. Stimulation with anti-CD3/CD8 increases the number of CB2-bearing CD3+, CD4+ and CD8+ cells, as well as CB1-bearing FoxP3+ cells. There was an inverse association between the number of reduced CD4+ CB2+ and IRS profiles, including M1 macrophage, T helper-(Th)-1 and Th-17 phenotypes. MDD is characterised by lowered basal FoxP3+ CB1+% and higher CD20+ CB2+%. 33.2% of the variance in the depression phenome (including severity of depression, anxiety and current suicidal behaviours) is explained by CD20+ CB2+ % (positively) and CD3+ CB2+% (inversely). All five immune cell populations were significantly increased by 10 µg/mL of CBD administration. Reductions in FoxP3+ CB1+% and CD3+ /CD4+ CB2+% contribute to deficits in immune homoeostasis in MDD, while increased CD20+CB2+% may contribute to the pathophysiology of MDD by activating T-independent humoral immunity.

Peripheral endocannabinoids in major depressive disorder and alcohol use disorder: a systematic review

BACKGROUND

Major Depressive Disorder (MDD) and Alcohol Use Disorder (AUD) are two high-prevalent conditions where the Endocannabinoid system (ECS) is believed to play an important role. The ECS regulates how different neurotransmitters interact in both disorders, which is crucial for controlling emotions and responses to stress and reward stimuli. Measuring peripheral endocannabinoids (eCBs) in human serum and plasma can help overcome the limitations of detecting endocannabinoid levels in the brain. This systematic review aims to identify levels of peripheral eCBs in patients with MDD and/or AUD and find eCBs to use as diagnostic, prognostic biomarkers, and potential therapeutic targets.

METHODS

We conducted a systematic literature search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines from the earliest manuscript until October 22, 2023, in three electronic databases. We included studies of human adults who had a current diagnosis of AUD and/or MDD and evaluated plasma or serum endocannabinoids. We carefully considered known variables that may affect endocannabinoid levels.

RESULTS

We included 17 articles in this systematic review, which measured peripheral eCBs in 170 AUD and 359 MDD patients. Stressors increase peripheral 2-arachidonyl-glycerol (2-AG) concentrations, and 2-AG may be a particular feature of depression severity and chronicity. Anxiety symptoms are negatively correlated with anandamide (AEA) concentrations, and AEA significantly increases during early abstinence in AUD. Studies suggest a negative correlation between Oleoylethanolamide (OEA) and length of abstinence in AUD patients. They also show a significant negative correlation between peripheral levels of AEA and OEA and fatty acid amide hydrolase (FAAH) activity. Eicosapentaenoylethanolamide (EPEA) is correlated to clinical remission rates in depression. Included studies show known variables such as gender, chronicity, symptom severity, comorbid psychiatric symptoms, length of abstinence in the case of AUD, and stress-inducibility that can affect peripheral eCBs.

CONCLUSIONS

This systematic review highlights the important role that the ECS plays in MDD and AUD. Peripheral eCBs appear to be useful biomarkers for these disorders, and further research may identify potential therapeutic targets. Using accessible biological samples such as blood in well-designed clinical studies is crucial to develop novel therapies for these disorders.

Therapeutic potential of cannabidiol in depression

Major depressive disorder (MDD) is a widespread and debilitating condition affecting a significant portion of the global population. Traditional treatment for MDD has primarily involved drugs that increase brain monoamines by inhibiting their uptake or metabolism, which is the basis for the monoaminergic hypothesis of depression. However, these treatments are only partially effective, with many patients experiencing delayed responses, residual symptoms, or complete non-response, rendering the current view of the hypothesis as reductionist. Cannabidiol (CBD) has shown promising results in preclinical models and human studies. Its mechanism is not well-understood, but may involve monoamine and endocannabinoid signaling, control of neuroinflammation and enhanced neuroplasticity. This chapter will explore CBD's effects in preclinical and clinical studies, its molecular mechanisms, and its potential as a treatment for MDD.

Immunomodulatory effects of cannabinoids against viral infections: a review of its potential use in SARS-CoV2 infection

The COVID-19 pandemic is a global health crisis affecting millions of people worldwide. Along with vaccine development, there is also a priority to discover new drugs and treatments. One approach involves modulating the immune system to manage inflammation and cytokine storms. Patients with a high severity of complications exhibit a high level of inflammatory cytokines, particularly IL-6, in the airways and other infected tissues. Several studies have reported the function of the endocannabinoid system in regulating inflammation and different immune responses. Cannabinoids are a class of natural chemicals found in the Cannabis plant. Recently, the anti-inflammatory properties of cannabinoids and their mediatory immunosuppression mechanisms through the endocannabinoid system have engrossed scientists in the health field for infectious conditions. Research suggests that the immune system can regulate cytokine activation through cannabinoid receptors, particularly with Cannabidiol (CBD), the second most prevalent compound in cannabis. While CBD has been deemed safe by the World Health Organization and shows no signs of abuse potential, excessive CBD use may lead to respiratory depression. CBD shows promise in reducing immune cell recruitment and cytokine storms in organs affected by SARS-CoV2. However, before clinical use, it's crucial to evaluate cannabinoid-based medications' active ingredient concentrations and potential interactions with other drugs, along with associated side effects. Indication-based dosing, consistent formulations, and ensuring purity and potency are essential. This review highlights cannabinoids' effects on COVID-19 management and prognosis, drawing from preclinical and clinical studies.

The Use of Compounds Derived from Cannabis sativa in the Treatment of Epilepsy, Painful Conditions, and Neuropsychiatric and Neurodegenerative Disorders

Neurological disorders present a wide range of symptoms and challenges in diagnosis and treatment. Cannabis sativa, with its diverse chemical composition, offers potential therapeutic benefits due to its anticonvulsive, analgesic, anti-inflammatory, and neuroprotective properties. Beyond cannabinoids, cannabis contains terpenes and polyphenols, which synergistically enhance its pharmacological effects. Various administration routes, including vaporization, oral ingestion, sublingual, and rectal, provide flexibility in treatment delivery. This review shows the therapeutic efficacy of cannabis in managing neurological disorders such as epilepsy, neurodegenerative diseases, neurodevelopmental disorders, psychiatric disorders, and painful pathologies. Drawing from surveys, patient studies, and clinical trials, it highlights the potential of cannabis in alleviating symptoms, slowing disease progression, and improving overall quality of life for patients. Understanding the diverse therapeutic mechanisms of cannabis can open up possibilities for using this plant for individual patient needs.

Cannabis Science and Therapeutics: An Overview for Clinicians

Cannabis-based therapeutics have garnered increasing attention in recent years as patients seek alternative treatments for various medical conditions. This narrative review provides a comprehensive overview of the science behind the medical use of cannabis, focusing on the medical evidence for commonly treated conditions. In addition, the review addresses the practical considerations of using cannabis as a therapeutic agent, offering insights into dosing strategies, variations in cannabinoid formulation, and individual patient responses. Precautions, adverse consequences, and drug interactions are also discussed, with a focus on patient safety and the potential risks associated with cannabis use.

Therapeutic use of medical Cannabis in neurological diseases: a clinical update

The use of medical Cannabis has increased in recent years due to changing legal circumstances in many countries. Approval exists only for a few neurological conditions such as rare forms of epilepsy or spasticity in multiple sclerosis. Beyond that, however, medical Cannabis is used for a wide range of neurological conditions and symptoms. In Germany, in parallel with new legislation that has simplified the prescription of medical Cannabis, an accompanying survey has been implemented for which initial data are now available. In this context, our review provides an overview of the evidence for the therapeutic use of medical Cannabis in neurology, the potential benefits, and side effects.

Pharmacovigilance of unlicensed cannabidiol in European countries

Cannabidiol (CBD) is a multitarget agent possessing anti-inflammatory and antioxidant properties. Unlicensed CBD gained public favor for the care of general health and well-being as well as to get comfort from inflammatory complaints, pain, anxiety, mood, and sleep disorders. Safety profile of unlicensed CBD has been not sufficiently described. For this reason, suspected adverse reactions (SARs) to CBD unlicensed products were analyzed. Serious SARs to unlicensed CBD products in EudraVigilance, a system purchased by the European Medicines Agency, were analyzed for age, sex of the patient, adverse reactions, indication for use, and concomitant drugs. Serious SARs were 18.9% of all adverse events to unlicensed CBD; they were more frequent in men and adult people and, to a less extent, in children (3-11 years). About sex, in EudraVigilance serious Individual Cases Safety Reports of SARs to CBD in men are in the largest number (58.8%) with respect to women. Unlicensed CBD was used in the 38.8% of cases for treatment of epilepsy; more frequent adverse effects were: mental disorders, hepatic disorders, and aggravation of pre-existing epilepsy. Drugs or substances more frequently associated with SARs were the antiepileptics clobazam and valproic acid, followed by cannabis. Results suggest that precautions and appropriate surveillance of adverse effects should be taken when unlicensed CBD is used.

Deciphering the mechanisms of reciprocal regulation or interdependence at the cannabinoid CB1 receptors and cyclooxygenase-2 level: Effects on mood, cognitive implications, and synaptic signaling

The lipid endocannabinoid system refers to endogenous cannabinoids (eCBs), the enzymes involved in their synthesis and metabolism, and the G protein-coupled cannabinoid receptors (GPCRs), CB1, and CB2. CB1 receptors (CB1Rs) are distributed in the brain at presynaptic terminals. Their activation induces inhibition of neurotransmitter release, which are gamma-aminobutyric acid (GABA), glutamate (Glu), dopamine, norepinephrine, serotonin, and acetylcholine. Postsynaptically localized CB1Rs regulate the activity of selected ion channels and N-methyl-D-aspartate receptors (NMDARs). CB2Rs are mainly peripheral and will not be considered here. Anandamide metabolism, mediated by cyclooxygenase-2 (COX-2), generates anandamide-derived prostanoids. In addition, COX-2 regulates the formation of CB1 ligands, which reduce excitatory transmission in the hippocampus (HC). The role of CB1Rs and COX-2 has been described in anxiety, depression, and cognition, among other central nervous system (CNS) disorders, affecting neurotransmission and behavior of the synapses. This review will analyze common pathways, mechanisms, and behavioral effects of manipulation at the CB1Rs/COX-2 level.

[Interest and mechanisms of action of ketamine in alcohol addiction- A review of clinical and preclinical studies]

Alcohol Use Disorder (AUD) is a psychiatric condition characterized by chronic and excessive drinking despite negative consequences on overall health and social or occupational functioning. There are currently limited treatment options available for AUD, and the effects size and the response rates to these treatments are often low to moderate. The World Health Organization has identified the development of medications to treat AUD as one of its 24 priorities. This past decade was marked by a renewed interest in psychedelic use in psychiatry. At the centre of this renaissance, ketamine, an atypical psychedelic already used in the treatment of major depression, is an NMDA receptor antagonist that exists as a racemic compound made of two enantiomers, S-ketamine, and R-ketamine. Each form can be metabolized into different metabolites, some of which having antidepressant properties. In this article, we review both clinical and preclinical studies on ketamine and its metabolites in the treatment of AUD. Preclinical as well as clinical studies have revealed that ketamine is effective in reducing withdrawal symptoms and alcohol craving. Convergent data showed that antidepressant properties of ketamine largely contribute to the decreased likelihood of alcohol relapse, especially in patients undergoing ketamine-assisted psychotherapies. Its effectiveness is believed to be linked with its ability to regulate the glutamatergic pathway, enhance neuroplasticity, rewire brain resting state network functional connectivity and decrease depressive-like states. However, it remains to further investigate (i) why strong differences exist between male and female responses in preclinical studies and (ii) the respective roles of each of the metabolites in the ketamine effects in both genders. Interestingly, current studies are also focusing on ketamine addiction and the comorbidity between alcohol addiction and depression occurring more frequently in females.

A Prospective Comparison of Bipolar I and II Subjects with and without Comorbid Cannabis Use Disorders from the COGA Dataset

OBJECTIVE

The comorbidity of alcohol and substance use disorders among persons with bipolar disorder is elevated, as indicated by epidemiological and clinical studies. Following alcohol use, cannabis is the most frequently used and abused illicit substance among bipolar individuals, and such use may lead to comorbid cannabis use disorders (CUD). Previous research indicated that CUDs were related to a more severe course of bipolar disorder and higher rates of other comorbid alcohol and substance use disorders. Few studies, however, have conducted longitudinal research on this comorbidity. The aim of this study is to investigate the influence of CUD on the course of bipolar I and II individuals during a 5-year follow-up.

METHODS

The characteristics of bipolar disorder, cannabis use disorders, and other alcohol and substance use disorders, as well as comorbid mental disorders, were assessed using a standardized semi-structured interview (SSAGA) at both baseline and the 5-year follow-up. N = 180 bipolar I and II patients were subdivided into groups of with and without comorbid cannabis use disorders (CUD).

RESULTS

Of the 77 bipolar I and 103 bipolar II patients, n = 65 (36.1%) had a comorbid diagnosis of any CUD (DSM-IV cannabis abuse or dependence). Comorbid bipolar patients with CUD had higher rates of other substance use disorders and posttraumatic stress disorders, more affective symptoms, and less psychosocial functioning at baseline and at 5-year follow-up. In contrast to previously reported findings, higher rates of anxiety disorders and bipolar disorder complications (e.g., mixed episodes, rapid cycling, and manic or hypomanic episodes) were not found. The effect of CUD on other substance use disorders was confirmed using moderation analyses.

CONCLUSIONS

A 5-year prospective evaluation of bipolar patients with and without CUD confirmed previous investigations, suggesting that the risk of other substance use disorders is significantly increased in comorbid individuals. CUD has a moderation effect, while no effect was found for other mental disorders. Findings from this study and previous research may be due to the examination of different phenotypes (Cannabis use vs. CUD) and sample variation (family study vs. clinical and epidemiological populations).

Psychological Interventions for Cannabis Use among Adolescents and Young Adults: A Systematic Review

Regular cannabis use during adolescence can lead to cognitive, psychological, and social consequences, causing significant distress. Although psychological interventions are the mainstay type of treatment for cannabis use disorder, the results remain mixed among youths. The objective of this review is twofold: to identify the existing psychological interventions for cannabis use among youths, and to assess the evidence regarding the effectiveness of those interventions. Randomized controlled trials focused exclusively on cannabis use among adolescents and young adults were included. Three databases-Embase, PsycInfo, and PubMed-were searched to identify relevant peer-reviewed manuscripts published before February 2022 in English and French. The risk of bias was assessed using the Cochrane Collaboration's tool. Twenty-five randomized controlled trials were included. Fourteen studies reported a significant outcome related to cannabis use. These were mainly non-intensive, online interventions that aimed to improve the patients' relationships and emotion regulation. This review highlights the need to conduct additional randomized control trials that target cannabis use disorder specifically among adolescents. These randomized control trials should also aim to reduce the risk of bias related to psychiatric comorbidities as well as detection and attrition problems.

Challenges and considerations for treating PTSD with medicinal cannabis: the Australian clinician's perspective

INTRODUCTION

Preclinical and experimental research have provided promising evidence that medicinal cannabis may be efficacious in the treatment of posttraumatic stress disorder (PTSD). However, implementation of medicinal cannabis into routine clinical therapies may not be straightforward.

AREAS COVERED

In this review, we describe some of the clinical, practical, and safety challenges that must be addressed for cannabis-based treatment of PTSD to be feasible in a real-world setting. These issues are especially prevalent if medicinal cannabis is to be combined with trauma-focused psychotherapy.

EXPERT OPINION

Future consideration of the clinical and practical considerations of cannabis use in PTSD therapy will be essential to both the efficacy and safety of the treatment protocols that are being developed. These issues include dose timing and titration, potential for addiction, product formulation, windows of intervention, and route of administration. In particular, exposure therapy for PTSD involves recall of intense emotions, and the interaction between cannabis use and reliving of trauma memories must be explored in terms of patient safety and impact on therapeutic outcomes.