Therapeutic Potential of Cannabidiol, Cannabidiolic Acid, and Cannabidiolic Acid Methyl Ester as Treatments for Nausea and Vomiting

Minor Cannabinoid Profile of Unregulated Cannabidiol Products

Background: Although the majority of cannabinoid research has focused on delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD), there is increasing interest in the therapeutic effects of other phytocannabinoid compounds (i.e., minor cannabinoids), as there is little known about their effects or interaction with CBD. The current study objective was to determine the concentrations of 15 minor cannabinoids in unregulated, over-the-counter CBD products. Methods: A cross-section sample of 80 local and national brands of hemp-derived oil products was purchased both online and in local retail outlets in central Kentucky. Epidiolex® was included as a regulated control. Samples from each product were extracted by solvent extraction and quantified by liquid-chromatography tandem mass-spectrometry. The targeted cannabinoids were: cannabidiolic acid (CBDA), cannabidivarin (CBDV), cannabidivarinic acid, Δ9-tetrahydrocannabivarin, Δ9-tetrahydrocannabivarinic acid, Δ9-tetrahydrocannabinolic acid-A, Δ8-tetrahydrocannabinol (Δ8-THC), cannabigerol (CBG), cannabigerolic acid, cannabinol (CBN), cannabinolic acid, cannabicyclol (CBL), cannabicyclolic acid, cannabichromene (CBC) and cannabichromenic acid. Results: Among the unregulated products included in this analysis, the most frequently detected minor cannabinoids were CBDV (100% of samples tested), CBG (77%), CBC (72%), CBN (67%), CBL (67%), and CBDA (51%). Δ8-THC was not detected in any of the products tested. Concentrations of these cannabinoids varied widely from trace concentrations to several mg/mL (e.g., CBDA: 0.006-12.258 mg/mL). Conclusions: These data indicate CBD products often contain minor cannabinoids, although the array and concentrations of these cannabinoids vary widely across products. The concentrations of these minor cannabinoids are largely absent from product labels, leaving consumers uninformed about product contents.

The Pharmacokinetics and Pharmacodynamics of a Hemp-Derived "Full-Spectrum" Oral Cannabinoid Product with a 1:1 Ratio of Cannabidiol to Cannabidiolic Acid and Delta-9-Tetrahydrocannabinol to Delta-9-Tetrahydrocannabinolic Acid: A Double-Blind, Placebo-Controlled, Within-Subjects Human Laboratory Study

Aim: To examine the acute pharmacokinetics (PK) and pharmacodynamics (PD) of a patented oral cannabinoid product containing a botanical hemp-derived "full-spectrum" extract with an approximate 1:1 ratio of cannabidiol (CBD) to cannabidiolic acid (CBDA) and delta-9-tetrahydrocannabinol (THC) to delta-9-tetrahydrocannabinolic acid (THCA). Methods: Healthy adults (n = 15) ingested soft gels containing 0 (placebo), and approximately 1, 2, and 4 mg/kg of total cannabinoids (combination of CBD, CBDA, THC, THCA, and other minor cannabinoids) in an ascending-dose order in four experimental sessions separated by ≥1 week (the placebo condition occurred randomly within the dose sequence). Mean doses (mg) of primary cannabinoids in the active drug conditions were: 1 mg/kg condition (CBD = 41.1, CBDA = 43.7, THC = 2.2, THCA = 1.6), 2 mg/kg condition (CBD = 73.4, CBDA = 77.9, THC = 3.9, THCA = 2.9), and 4 mg/kg condition (CBD = 134.5, CBDA = 142.8, THC = 7.2, THCA = 5.3). PD outcomes (subjective, cognitive, and physiological effects) were measured before and repeatedly for 8 h after dosing. Plasma specimens were collected throughout the 8-h sessions and at 24- and 48-h post-dosing. PK outcomes included peak plasma concentration (Cmax) and time to maximum concentration (Tmax). Results: For PD outcomes, few differences were observed between 1 mg/kg and placebo. However, relative to placebo, 2 mg/kg and 4 mg/kg produced small to moderate increases in subjective drug effects, including abuse liability items (e.g., "like"), and 4 mg/kg also impaired working memory performance. Generally, PD effects peaked 3-5 h post-dosing and returned to baseline by 8 h. Dose-orderly increases in Cmax were observed for CBD, CBDA, THC, THCA, and their respective metabolites (e.g., 7-COOH-CBD, THCCOOH), which were often detectable 48 h post-dosing. Across all doses, Cmax for CBDA and THCA was 19-25-fold higher and Tmax was up to 2-fold earlier compared with CBD and THC, respectively. Conclusions: Acute administration of a "full-spectrum" hemp-derived cannabinoid product produced dose-orderly effects; the highest dose elicited several adverse events and produced moderate cognitive impairment and subjective intoxication, despite containing a relatively low dose of THC (mean: 7.2 mg). Carboxylated cannabinoids (e.g., CBDA) exhibited substantially greater bioavailability and faster absorption compared with decarboxylated cannabinoids (e.g., CBD). Additional systematic research is needed to characterize how constituent profile impacts the effects of cannabinoid products, and more studies directly comparing carboxylated and decarboxylated compounds appear warranted.

Semi-Synthesis of Dimeric Cannabidiol Derivatives and Evaluation of their Affinity at Neurological Targets

Cannabidiol (CBD) is a natural product associated with a wide range of biological and therapeutic activities. Despite the widespread cultural acceptance of CBD as a medicinal agent, much remains to be determined regarding its precise mechanism(s) of action in treating multiple conditions. CBD has been shown to promiscuously interact with several neurological targets with varying affinities. To expand the chemical space of phytocannabinoids and develop novel chemical compounds, we have designed and synthesized a series of CBD and Δ8-THC homodimers, and CBD/Δ8-THC heterodimers. The capacity of the dimers to interact with a panel of CNS targets was explored along with the capacity to activate CB1 receptors, as measured by a GIRK channel activation assay. In the panel screen, the dimers were shown to be generally more active toward 5-HT2B and sigma 2 receptors with a range of Ki values from 0.6 to 8.7 μM. These findings provide early evidence that this new class of dimers can serve as novel chemical entities to explore receptor function and the potential for these dimers to have bivalent, bitopic, or dual mechanisms of action.

Therapeutic potential of cannabidiol polypharmacology in neuropsychiatric disorders

Cannabidiol (CBD), the primary non-intoxicating compound in cannabis, is currently approved for treating rare, treatment-resistant seizures. Recent preclinical research suggests that CBD's multifaceted mechanisms of action in the brain, which involve multiple molecular targets, underlie its neuroprotective, anti-inflammatory, anxiolytic, and antipsychotic effects. Clinical trials are also exploring CBD's therapeutic potential beyond its current uses. This review focuses on CBD's polypharmacological profile and discusses the latest preclinical and clinical findings regarding its efficacy in neuropsychiatric disorders. Existing evidence suggests that CBD's ability to modulate multiple signaling pathways may benefit neuropsychiatric disorders, and we propose further research areas to clarify its mechanisms, address data gaps, and refine its therapeutic indications.

A sleepy cannabis constituent: cannabinol and its active metabolite influence sleep architecture in rats

Medicinal cannabis is being used worldwide and there is increasing use of novel cannabis products in the community. Cannabis contains the major cannabinoids, Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD), but also an array of minor cannabinoids that have undergone much less pharmacological characterization. Cannabinol (CBN) is a minor cannabinoid used in the community in "isolate' products and is claimed to have pro-sleep effects comparable to conventional sleep medications. However, no study has yet examined whether it impacts sleep architecture using objective sleep measures. The effects of CBN on sleep in rats using polysomnography were therefore examined. CBN increased total sleep time, although there was evidence of biphasic effects with initial sleep suppression before a dramatic increase in sleep. CBN increased both non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. The magnitude of the effect of CBN on NREM was comparable to the sleep aid zolpidem, although, unlike CBN, zolpidem did not influence REM sleep. Following CBN dosing, 11-hydroxy-CBN, a primary metabolite of CBN surprisingly attained equivalently high brain concentrations to CBN. 11-hydroxy-CBN was active at cannabinoid CB1 receptors with comparable potency and efficacy to Δ9-THC, however, CBN had much lower activity. We then discovered that the metabolite 11-hydroxy-CBN also influenced sleep architecture, albeit with some subtle differences from CBN itself. This study shows CBN affects sleep using objective sleep measures and suggests an active metabolite may contribute to its hypnotic action.

Cannabinoid hyperemesis syndrome: genetic susceptibility to toxic exposure

Cannabinoid hyperemesis syndrome presents as a complex of symptoms and signs encompassing nausea, vomiting, abdominal pain, and hot water bathing behavior, most typically in a heavy cannabis user. Its presentation is frequently associated with hypothalamic-pituitary-adrenal axis activation with stress and weight loss. Recent investigation has identified five statistically significant mutations in patients distinct from those of frequent cannabis users who lack the symptoms, affecting the TRPV1 receptor, two dopamine genes, the cytochrome P450 2C9 enzyme that metabolizes tetrahydrocannabinol, and the adenosine triphosphate-binding cassette transporter. The syndrome is associated with escalating intake of high potency cannabis, or alternatively, other agonists of the cannabinoid-1 receptor including synthetic cannabinoids. Some patients develop environmental triggers in scents or foods that suggest classical conditioned responses. Various alternative "causes" are addressed and refuted in the text, including exposure to pesticides, neem oil or azadirachtin. Nosological confusion of cannabinoid hyperemesis syndrome has arisen with cyclic vomiting syndrome, whose presentation and pathophysiology are clearly distinct. The possible utilization of non-intoxicating antiemetic cannabis components in cannabis for treatment of cannabinoid hyperemesis syndrome is addressed, along with future research suggestions in relation to its genetic foundation and possible metabolomic signatures.

Unleashing the therapeutic role of cannabidiol in dentistry

Cannabidiol (CBD) found in Cannabis sativa is a non-psychoactive compound which is capable of binding to CB1 and CB2 receptors. CBD has recently gained interest in dentistry although it has not been explored sufficiently yet. The therapeutic effects of CBD include anti-inflammatory, analgesic, antioxidant, biological and osteoinductive properties. The aim of this review is to highlight these effects with respect to various oral conditions and shed light on the current limitations and prospects for the use of CBD in maintaining oral health.

Unraveling the molecular basis of cannabidiolic acid methyl Ester's anti-depressive effects in a rat model of treatment-resistant depression

Major depressive disorder (MDD) stands as a significant cause of disability globally. Cannabidiolic Acid-Methyl Ester (CBDA-ME) (EPM-301, HU-580), a derivative of Cannabidiol, demonstrates immediate antidepressant-like effects, yet it has undergone only minimal evaluation in psychopharmacology. Our goal was to investigate the behavioral and potential molecular mechanisms associated with the chronic oral administration of this compound in the Wistar Kyoto (WKY) genetic model of treatment-resistant depression. Male WKY rats were subjected to behavioral assessments before and after receiving chronic (14-day) oral doses of CBDA-ME (0.5 mg/kg), 15 mg/kg of imipramine or vehicle. At the end of the study, plasma corticosterone levels and mRNA expression of various genes in the medial Prefrontal Cortex and Hippocampus were measured. Behavioral outcomes from CBDA-ME treatment indicated an antidepressant-like effect similar to imipramine, as oral ingestion reduced immobility and increased swimming duration in the Forced Swim Test. Neither treatment influenced locomotion in the Open Field Test nor preference in the Saccharin Preference Test. The behavioral impact in WKY rats coincided with reduced corticosterone serum levels, upregulated mRNA expression of Cannabinoid receptor 1, Fatty Acid Amide Hydrolase, and Corticotropin-Releasing Hormone Receptor 1, alongside downregulation of the Serotonin Transporter in the hippocampus. Additionally, there was an upregulation of CB1 mRNA expression and downregulation of Brain-Derived Neurotrophic Factor in the mPFC. These findings contribute to our limited understanding of the antidepressant effects of CBDA-ME and shed light on its potential psychopharmacological mechanisms. This discovery opens up possibilities for utilizing cannabinoids in the treatment of major depressive disorder and related conditions.

Cannabidiol and Intestinal Motility: a Systematic Review

Cannabidiol (CBD) is a non-intoxicating cannabinoid extracted from the cannabis plant that is used for medicinal purposes. Ingestion of CBD is claimed to address several pathologies, including gastrointestinal disorders, although limited evidence has been generated thus far to substantiate many of its health claims. Nevertheless, CBD usage as an over-the-counter treatment for gastrointestinal disorders is likely to expand in response to increasing commercial availability, permissive legal status, and acceptance by consumers. This systematic review critically evaluates the knowledge boundaries of the published research on CBD, intestinal motility, and intestinal motility disorders. Research on CBD and intestinal motility is currently limited but does support the safety and efficacy of CBD for several therapeutic applications, including seizure disorders, inflammatory responses, and upper gastrointestinal dysfunction (i.e., nausea and vomiting). CBD, therefore, may have therapeutic potential for addressing functional gastrointestinal disorders. The results of this review show promising in vitro and preclinical data supporting a role of CBD in intestinal motility. This includes improved gastrointestinal-related outcomes in murine models of colitis. These studies, however, vary by dose, delivery method, and CBD-extract composition. Clinical trials have yet to find a conclusive benefit of CBD on intestinal motility disorders, but these trials have been limited in scope. In addition, critical factors such as CBD dosing parameters have not yet been established. Further research will establish the efficacy of CBD in applications to address intestinal motility.

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

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

Fetal cannabidiol (CBD) exposure alters thermal pain sensitivity, problem-solving, and prefrontal cortex excitability

Thousands of people suffer from nausea with pregnancy each year. Nausea can be alleviated with cannabidiol (CBD), a primary component of cannabis that is widely available. However, it is unknown how fetal CBD exposure affects embryonic development and postnatal outcomes. CBD binds and activates receptors that are expressed in the fetal brain and are important for brain development, including serotonin receptors (5HT1A), voltage-gated potassium (Kv)7 receptors, and the transient potential vanilloid 1 receptor (TRPV1). Excessive activation of each of these receptors can disrupt neurodevelopment. Here, we test the hypothesis that fetal CBD exposure in mice alters offspring neurodevelopment and postnatal behavior. We administered 50 mg/kg CBD in sunflower oil or sunflower oil alone to pregnant mice from embryonic day 5 through birth. We show that fetal CBD exposure sensitizes adult male offspring to thermal pain through TRPV1. We show that fetal CBD exposure decreases problem-solving behaviors in female CBD-exposed offspring. We demonstrate that fetal CBD exposure increases the minimum current required to elicit action potentials and decreases the number of action potentials in female offspring layer 2/3 prefrontal cortex (PFC) pyramidal neurons. Fetal CBD exposure reduces the amplitude of glutamate uncaging-evoked excitatory post-synaptic currents, consistent with CBD-exposed female problem-solving behavior deficits. Combined, these data show that fetal CBD exposure disrupts neurodevelopment and postnatal behavior in a sex specific manner.

Cannabidiol for Oral Health: A New Promising Therapeutical Tool in Dentistry

The medical use of cannabis has a very long history. Although many substances called cannabinoids are present in cannabis, Δ9tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD) and cannabinol (CBN) are the three main cannabinoids that are most present and described. CBD itself is not responsible for the psychotropic effects of cannabis, since it does not produce the typical behavioral effects associated with the consumption of this drug. CBD has recently gained growing attention in modern society and seems to be increasingly explored in dentistry. Several subjective findings suggest some therapeutic effects of CBD that are strongly supported by research evidence. However, there is a plethora of data regarding CBD's mechanism of action and therapeutic potential, which are in many cases contradictory. We will first provide an overview of the scientific evidence on the molecular mechanism of CBD's action. Furthermore, we will map the recent developments regarding the possible oral benefits of CBD. In summary, we will highlight CBD's promising biological features for its application in dentistry, despite exiting patents that suggest the current compositions for oral care as the main interest of the industry.

Cannabinoid Receptor 2 Blockade Prevents Anti-Depressive-like Effect of Cannabidiol Acid Methyl Ester in Female WKY Rats

The pathophysiology of major depressive disorder (MDD) is diverse and multi-factorial, yet treatment strategies remain limited. While women are twice as likely to develop the disorder as men, many animal model studies of antidepressant response rely solely on male subjects. The endocannabinoid system has been linked to depression in clinical and pre-clinical studies. Cannabidiolic Acid-Methyl Ester (CBDA-ME, EPM-301) demonstrated anti-depressive-like effects in male rats. Here, we explored acute effects of CBDA-ME and some possible mediating mechanisms, using a depressive-like genetic animal model, the Wistar-Kyoto (WKY) rat. In Experiment 1, Female WKY rats underwent the Forced swim test (FST) following acute CBDA-ME oral ingestion (1/5/10 mg/kg). In Experiment 2, Male and female WKY rats underwent the FST after injection of CB1 (AM-251) and CB2 (AM-630) receptor antagonists 30 min before acute CBDA-ME ingestion (1 mg/kg, males; 5 mg/kg, females). Serum levels of Brain-Derived Neurotrophic Factor (BDNF), numerous endocannabinoids and hippocampal Fatty Acid Amide Hydrolase (FAAH) levels were assessed. Results indicate that females required higher doses of CBDA-ME (5 and 10 mg/kg) to induce an anti-depressive-like effect in the FST. AM-630 blocked the antidepressant-like effect in females, but not in males. The effect of CBDA-ME in females was accompanied by elevated serum BDNF and some endocannabinoids and low hippocampal expression of FAAH. This study shows a sexually diverse behavioral anti-depressive response to CBDA-ME and possible underlying mechanisms in females, supporting its potential use for treating MDD and related disorders.

Targeting the endocannabinoid system for the treatment of abdominal pain in irritable bowel syndrome

The management of visceral pain in patients with disorders of gut-brain interaction, notably irritable bowel syndrome, presents a considerable clinical challenge, with few available treatment options. Patients are increasingly using cannabis and cannabinoids to control abdominal pain. Cannabis acts on receptors of the endocannabinoid system, an endogenous system of lipid mediators that regulates gastrointestinal function and pain processing pathways in health and disease. The endocannabinoid system represents a logical molecular therapeutic target for the treatment of pain in irritable bowel syndrome. Here, we review the physiological and pathophysiological functions of the endocannabinoid system with a focus on the peripheral and central regulation of gastrointestinal function and visceral nociception. We address the use of cannabinoids in pain management, comparing them to other treatment modalities, including opioids and neuromodulators. Finally, we discuss emerging therapeutic candidates targeting the endocannabinoid system for the treatment of pain in irritable bowel syndrome.

Cannabinoids as Immune System Modulators: Cannabidiol Potential Therapeutic Approaches and Limitations

Introduction: Cannabidiol (CBD) is the second most abundant Phytocannabinoid in Cannabis extracts. CBD has a binding affinity for several cannabinoid and cannabinoid-associated receptors. Epidiolex (oral CBD solution) has been lately licensed by the Food and Drug Administration (FDA) for the treatment of pediatric epileptic seizures. Methods: In this review, we discussed the most promising applications of CBD for chronic inflammatory conditions, namely CBD's anti-inflammatory effects during inflammatory bowel disease, coronavirus disease (antiviral effect), brain pathologies (neuroprotective and anti-inflammatory properties), as well as CBD immunomodulatory and antitumoral activities in the tumor microenvironment. Special focus was shed on the main therapeutic mechanisms of action of CBD, particularly in the control of the immune system and the endocannabinoid system. Results: Findings suggest that CBD is a potent immunomodulatory drug as it has manifested immunosuppressive properties in the context of sterile inflammation (e.g., inflammatory bowel disease, rheumatoid arthritis, and neurodegenerative diseases), and immunoprotective effects during viral infections (e.g. COVID-19) Similarly, CBD has exhibited a selective response toward cancer types by engaging different targets and signaling pathways. These results are in favor of the primary function of the endocannabinoid system which is homeostatic maintenance. Conclusion: The presented evidence suggests that the endocannabinoid system is a prominent target for the treatment of inflammatory and autoimmune diseases, rheumatoid diseases, viral infections, neurological and psychological pathologies, and cancer. Moreover, the antitumoral activities of CBD have been suggested to be potentially used in combination with chemo- or immunotherapy during cancer. However, clinical results are still lacking, which raises a challenge to apply translational cannabis research to the human immune system.

Cannabinoid drugs against chemotherapy-induced adverse effects: focus on nausea/vomiting, peripheral neuropathy and chemofog in animal models

Although new drugs are being developed for cancer treatment, classical chemotherapeutic agents are still front-line therapies, despite their frequent association with severe side effects that can hamper their use. Cannabinoids may prevent or palliate some of these side effects. The aim of the present study is to review the basic research which has been conducted evaluating the effects of cannabinoid drugs in the treatment of three important side effects induced by classical chemotherapeutic agents: nausea and vomiting, neuropathic pain and cognitive impairment. Several published studies have demonstrated that cannabinoids are useful in preventing and reducing the nausea, vomits and neuropathy induced by different chemotherapy regimens, though other side effects can occur, such as a reduction of gastrointestinal motility, along with psychotropic effects when using centrally-acting cannabinoids. Thus, peripherally-acting cannabinoids and new pharmacological options are being investigated, such as allosteric or biased agonists. Additionally, due to the increase in the survival of cancer patients, there are emerging data that demonstrate an important cognitive deterioration due to chemotherapy, and because the cannabinoid drugs have a neuroprotective effect, they could be useful in preventing chemotherapy-induced cognitive impairment (as demonstrated through studies in other neurological disorders), but this has not yet been tested. Thus, although cannabinoids seem a promising therapeutic approach in the treatment of different side effects induced by chemotherapeutic agents, future research will be necessary to find pharmacological options with a safer profile. Moreover, a new line of research awaits to be opened to elucidate their possible usefulness in preventing cognitive impairment.

Anti-Microbial Activity of Phytocannabinoids and Endocannabinoids in the Light of Their Physiological and Pathophysiological Roles

Antibiotic resistance has become an increasing challenge in the treatment of various infectious diseases, especially those associated with biofilm formation on biotic and abiotic materials. There is an urgent need for new treatment protocols that can also target biofilm-embedded bacteria. Many secondary metabolites of plants possess anti-bacterial activities, and especially the phytocannabinoids of the Cannabis sativa L. varieties have reached a renaissance and attracted much attention for their anti-microbial and anti-biofilm activities at concentrations below the cytotoxic threshold on normal mammalian cells. Accordingly, many synthetic cannabinoids have been designed with the intention to increase the specificity and selectivity of the compounds. The structurally unrelated endocannabinoids have also been found to have anti-microbial and anti-biofilm activities. Recent data suggest for a mutual communication between the endocannabinoid system and the gut microbiota. The present review focuses on the anti-microbial activities of phytocannabinoids and endocannabinoids integrated with some selected issues of their many physiological and pharmacological activities.

Stimulants and Depressor Drugs in the Sleep-Wake Cycle Modulation: The case of alcohol and cannabinoids

A complex neurobiological network drives the sleep-wake cycle. In addition, external stimuli, including stimulants or depressor drugs, also influence the control of sleep. Here we review the recent advances that contribute to the comprehensive understanding of the actions of stimulants and depressor compounds, such as alcohol and cannabis, in sleep regulation. The objective of this review is to highlight the neurobiological mechanism engaged by alcohol and cannabis in sleep control.