The safety and efficacy of low oral doses of cannabidiol: An evaluation of the evidence

“Global interest in the non-intoxicating cannabis constituent, cannabidiol (CBD), is increasing with claims of therapeutic effects across a diversity of health conditions. At present, there is sufficient clinical trial evidence to support the use of high oral doses of CBD (e.g., 10-50 mg/kg) in treating intractable childhood epilepsies. However, a question remains as to whether “low-dose” CBD products confer any therapeutic benefits. This is an important question to answer, as low-dose CBD products are widely available in many countries, often as nutraceutical formulations. The present review therefore evaluated the efficacy and safety of low oral doses of CBD. The review includes interventional studies that measured the clinical efficacy in any health condition and/or safety and tolerability of oral CBD dosed at less than or equal to 400 mg per day in adult populations (i.e., ≥18 years of age). Studies were excluded if the product administered had a Δ9 -tetrahydrocannabinol content greater than 2.0%.

Therapeutic benefits of CBD became more clearly evident at doses greater than or equal to 300 mg. Increased dosing from 60 to 400 mg/day did not appear to be associated with an increased frequency of adverse effects. At doses of 300-400 mg, there is evidence of efficacy with respect to reduced anxiety, as well as anti-addiction effects in drug-dependent individuals. More marginal and less consistent therapeutic effects on insomnia, neurological disorders, and chronic pain were also apparent. Larger more robust clinical trials are needed to confirm the therapeutic potential of lower (i.e., <300 mg/day) oral doses of CBD.”

https://pubmed.ncbi.nlm.nih.gov/36259271/

https://ascpt.onlinelibrary.wiley.com/doi/10.1111/cts.13425

Cannabidiol as a personalized treatment for anxiety: clinical cases in Mexico

Drugs in Context

“Anxiety-related disorders are one of the most common mental health issues worldwide. Mexico has reported an increase in the prevalence of these ailments secondary to the confinement derived from the COVID-19 pandemic. Given the limitations of commonly used treatments for these disorders, a need arises to develop new pharmacological treatments for these patients. This paper has the primary objective of evaluating the efficacy and safety of cannabidiol isolate in drug compounding used as a personalized treatment in patients with anxiety disorders through the presentation of four clinical cases.”

https://pubmed.ncbi.nlm.nih.gov/36188636/

Social stress under binge-like alcohol withdrawal in adolescence: evidence of cannabidiol effect on maladaptive plasticity in rats

Psychological Medicine

“Background: Alcohol binge drinking may compromise the functioning of the nucleus accumbens (NAc), i.e. the neural hub for processing reward and aversive responses.

Methods: As socially stressful events pose particular challenges at developmental stages, this research applied the resident-intruder paradigm as a model of social stress, to highlight behavioural neuroendocrine and molecular maladaptive plasticity in rats at withdrawal from binge-like alcohol exposure in adolescence. In search of a rescue agent, cannabidiol (CBD) was selected due to its favourable effects on alcohol- and stress-related harms.

Results: Binge-like alcohol exposed intruder rats displayed a compromised defensive behaviour against the resident and a blunted response of the stress system, in addition to indexes of abnormal dopamine (DA)/glutamate plasticity and dysfunctional spine dynamics in the NAc. CBD administration (60 mg/kg) was able to: (1) increase social exploration in the binge-like alcohol exposed intruder rats, at the expenses of freezing time, and in control rats, which received less aggressive attacks from the resident; (2) reduce corticosterone levels independently on alcohol previous exposure; (3) restore DA transmission and (4) facilitate excitatory postsynaptic strength and remodelling.

Conclusions: Overall, the maladaptive behavioural and synaptic plasticity promoted by the intersection between binge-like alcohol withdrawal and exposure to adverse social stress can be rescued by a CBD détente effect that results in a successful defensive strategy, supported by a functional endocrine and synaptic plasticity. The current data highlight CBD’s relevant therapeutic potential in alcohol- and stress-related harms, and prompt further investigation on its molecular targets.”

https://pubmed.ncbi.nlm.nih.gov/36065905/

https://www.cambridge.org/core/journals/psychological-medicine/article/abs/social-stress-under-bingelike-alcohol-withdrawal-in-adolescence-evidence-of-cannabidiol-effect-on-maladaptive-plasticity-in-rats/0A68E4159FDCAF5592BD10DEC4DAC9F8

Cannabidiol impairs fear memory reconsolidation in female rats through dorsal hippocampus CB1 but not CB2 receptor interaction

European Neuropsychopharmacology

“Women present increased susceptibility to anxiety- and stress-related disorders compared to men. A potentially promising pharmacological-based strategy to regulate abnormal aversive memories disrupts their reconsolidation stage after reactivation and destabilization.

Male rodent findings indicate that cannabidiol (CBD), a relatively safe and effective treatment for several mental health conditions, can impair the reconsolidation of aversive memories. However, whether and how CBD influences it in females is still unknown.

The present study addressed this question in contextually fear-conditioned female rats.

We report that systemically administered CBD impaired their reconsolidation, reducing freezing expression for over a week. This action was restricted to a time when the reconsolidation presumably lasted (< six hours post-retrieval) and depended on memory reactivation/destabilization. Moreover, the impairing effects of CBD on memory reconsolidation relied on the activation of cannabinoid type-1 but not type-2 receptors located in the CA1 subregion of the dorsal hippocampus.

CBD applied directly to this brain area was sufficient to reproduce the effects of systemic CBD treatment. Contextual fear memories attenuated by CBD did not show reinstatement, an extinction-related feature. By demonstrating that destabilized fear memories are sensitive to CBD and how it hinders mechanisms in the DH CA1 that may restabilize them in female rats, the present findings concur that reconsolidation blockers are viable and could be effective in disrupting abnormally persistent and distressing aversive memories such as those related to posttraumatic stress disorder.”

https://pubmed.ncbi.nlm.nih.gov/36049316/

https://www.sciencedirect.com/science/article/abs/pii/S0924977X22008367?via%3Dihub

Cannabidiol ameliorates the anxiogenic and compulsive-like behaviors induced by chronic consumption of a high-carbohydrate diet in male mice

SpringerLink

“The excessive consumption of ultra-processed foods and the development of obesity has been associated with several comorbidities, including psychiatric disorders. Excess fat tissue promotes a low-intensity inflammatory state, mainly in the white tissue, which is essential in developing metabolic alterations and influences brain homeostasis.

In this scenario, Cannabidiol (CBD), a compound from Cannabis sativa, has presented anxiolytic and anti-inflammatory effects in murine models.

This study verified whether CBD treatment would ameliorate the compulsive-like and anxiety-like behaviors observed after mice’s chronic consumption of a high-refined carbohydrate (HC) diet.

BALB/c male mice received a control or HC diet for 12 weeks followed by vehicle and CBD (30 mg/Kg, i.p.) administration, and their behavior was evaluated in the Marble Burying test (MB) and Novel Suppressing Feeding test (NSF).

The sub-chronic, but not acute, treatment with CBD attenuated the compulsive-like and anxiogenic-like behavior induced by the HC diet.

Our data reinforced the harmful effects of the HC diet’s chronic consumption on compulsive and anxious behaviors and the potential of CBD as a drug treatment for psychiatric disorders associated with obesity.”

https://pubmed.ncbi.nlm.nih.gov/36040711/

https://link.springer.com/article/10.1007/s11011-022-01071-9

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

ijms-logo

“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.”

https://pubmed.ncbi.nlm.nih.gov/36012600/

https://www.mdpi.com/1422-0067/23/16/9333/htm

Broad-spectrum cannabis oil ameliorates reserpine-induced fibromyalgia model in mice

Biomedicine & Pharmacotherapy

“Fibromyalgia (FM) is an idiopathic disorder characterized by generalized pain and associated symptoms such as depression and anxiety.

Cannabis sativa shows different pharmacological activities, such as analgesic, anti-inflammatory, neuroprotective, and immunomodulatory. Associated with this, the use of an oil with low concentrations of THC can reduce the psychomimetic adverse effects of the plant. Therefore, the present study aimed to evaluate the analgesic effect of broad-spectrum cannabis oil with low THC concentration in an experimental model of FM.

Mechanical hyperalgesia, thermal allodynia, depressive- and anxious-related behavior, and locomotor activity were evaluated after reserpine (0.25 mg/kg; injected subcutaneously (s.c.) once daily for three consecutive days) administration.

Our results showed that oral administration of broad-spectrum cannabis oil (0.1, 1, and 3 mg/kg, p.o.) in a single dose on the 4th day inhibited mechanical hyperalgesia and thermal allodynia induced by reserpine. Relevantly, treatment during four days with broad-spectrum cannabis oil (0.1 mg/kg, p.o.) reduced mechanical hyperalgesia 1 h after reserpine administration.

Intraplantar treatment with cannabis oil significantly reversed mechanical and heat thermal nociception induced by reserpine injection. Interestingly, spinal and supraspinal administration of broad-spectrum cannabis oil completely inhibited mechanical hyperalgesia and thermal sensitivity induced by reserpine. The repeated cannabis oil administration, given daily for 14 days, markedly mitigated the mechanical and thermal sensitivity during the FM model, and its reduced depressive-like behavior induced by reserpine.

In summary, broad-spectrum cannabis oil is an effective alternative to reverse the reserpine-induced fibromyalgia model.”

https://pubmed.ncbi.nlm.nih.gov/35988425/

“In the present study, it was possible to observe that, regardless of the route of administration, broad-spectrum cannabis oil proved to be effective in reversing the mechanical hyperalgesia effects of the reserpine-induced fibromyalgia model. Furthermore, chronic treatment with broad-spectrum cannabis oil showed analgesic effects on mechanical hyperalgesia and heat allodynia and mitigated reserpine-induced passive stress-coping behavior and lower-self-care behavior in mice. Conjointly, our results point to broad-spectrum cannabis oil as a therapeutic alternative for the disorders caused by FM.”

https://www.sciencedirect.com/science/article/pii/S0753332222009416?via%3Dihub

Tetrahydrocannabinol and cannabidiol medicines for chronic pain and mental health conditions

SpringerLink

“Combination tetrahydrocannabinol (THC)/cannabidiol (CBD) medicines or CBD-only medicines are prospective treatments for chronic pain, stress, anxiety, depression, and insomnia. THC and CBD increase signaling from cannabinoid receptors, which reduces synaptic transmission in parts of the central and peripheral nervous systems and reduces the secretion of inflammatory factors from immune and glial cells.

The overall effect of adding CBD to THC medicines is to enhance the analgesic effect but counteract some of the adverse effects. There is substantial evidence for the effectiveness of THC/CBD combination medicines for chronic pain, especially neuropathic and nociplastic pain or pain with an inflammatory component. For CBD-only medication, there is substantial evidence for stress, moderate evidence for anxiety and insomnia, and minimal evidence for depression and pain.

THC/CBD combination medicines have a good tolerability and safety profile relative to opioid analgesics and have negligible dependence and abuse potential; however, should be avoided in patients predisposed to depression, psychosis and suicide as these conditions appear to be exacerbated. Non-serious adverse events are usually dose-proportional, subject to tachyphylaxis and are rarely dose limiting when patients are commenced on a low dose with gradual up-titration. THC and CBD inhibit several Phase I and II metabolism enzymes, which increases the exposure to a wide range of drugs and appropriate care needs to be taken. Low-dose CBD that appears effective for chronic pain and mental health has good tolerability and safety, with few adverse effects and is appropriate as an initial treatment.”

https://pubmed.ncbi.nlm.nih.gov/35796920/

“Tetrahydrocannabinol (THC) and cannabidiol (CBD) combination medicines and CBD-only medicines are prospective new treatments for chronic pain, stress, anxiety, depression, and insomnia, which are all medical conditions in need of better therapeutics. Both THC/CBD combination and CBD-only medicines could provide effective new treatment options for pain and mental health, respectively, and both have good safety and tolerability profiles relative to the current treatments.

THC and CBD combination medicines have a good safety and tolerability profile that is appropriate for opioid stage (stage 2–3) treatment of chronic pain. Low-dose CBD could be used as an initial treatment for chronic pain and for stress, anxiety, depression, and insomnia. High quality efficacy evidence is best for THC/CBD combination medicines for chronic pain and CBD-only medicines for stress and anxiety. “

https://link.springer.com/article/10.1007/s10787-022-01020-z

Cannabis: Chemistry, extraction and therapeutic applications

Chemosphere

“Cannabis, a genus of perennial indigenous plants is well known for its recreational and medicinal activities. Cannabis and its derivatives have potential therapeutic activities to treat epilepsy, anxiety, depression, tumors, cancer, Alzheimer’s disease, Parkinson’s disease, to name a few.

This article reviews some recent literature on the bioactive constituents of Cannabis, commonly known as phytocannabinoids, their interactions with the different cannabinoids and non-cannabinoid receptors as well as the significances of these interactions in treating various diseases and syndromes.

The biochemistry of some notable cannabinoids such as tetrahydrocannabinol, cannabidiol, cannabinol, cannabigerol, cannabichromene and their carboxylic acid derivatives is explained in the context of therapeutic activities.

The medicinal features of Cannabis-derived terpenes are elucidated for treating several neuro and non-neuro disorders. Different extraction techniques to recover cannabinoids are systematically discussed. Besides the medicinal activities, the traditional and recreational utilities of Cannabis and its derivatives are presented. A brief note on the legalization of Cannabis-derived products is provided.

This review provides comprehensive knowledge about the medicinal properties, recreational usage, extraction techniques, legalization and some prospects of cannabinoids and terpenes extracted from Cannabis.”

https://pubmed.ncbi.nlm.nih.gov/34838836/

“Cannabinoids have therapeutic effects against various health disorders.•

Medicinal effects are due to the interactions of cannabinoids with bio-receptors.•

Cannabinoids can be extracted from Cannabis plant products by eco-friendly extraction methods.”

https://www.sciencedirect.com/science/article/abs/pii/S0045653521034846?via%3Dihub

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The antidepressant and anxiolytic effects of cannabinoids in chronic unpredictable stress: a preclinical systematic review and meta-analysis

Translational Psychiatry

“Neuroscience research presents contradictory evidence in support of both the protective and destructive effects of cannabinoids in depression. Therefore, this systematic review and meta-analysis summarizes the existing preclinical literature on the effects of cannabinoid administration in the chronic unpredictable stress model of depression in order to evaluate the effects of cannabinoids and identify gaps in the literature. After protocol registration (PROSPERO #CRD42020219986), we systematically searched Scopus, Embase, Psychology & Behavioral Sciences Collection, APA PsychINFO, PubMed, CINAHL Complete, and ProQuest Dissertations & Theses Global from the earliest record of the databases, February 1964, to November 2020 for articles that met inclusion criteria (e.g., rodent subjects and administration of a cannabinoid. A total of 26 articles were included representing a sample size estimate of 1132 rodents with the majority of articles administering daily intraperitoneal injections during chronic unpredictable stress. These articles were evaluated using a modified SYRCLE’s risk-of-bias tool. For each continuous behavioral measure, the standardized mean difference was calculated between cannabinoid and vehicle groups in rodents subjected to chronic unpredictable stress. The effects of cannabinoids on depressive-like behavior was evaluated using a multilevel mixed-effects model with effect size weights nested within control groups. Cannabinoid administration moderately improved the pooled negative effects of chronic unpredictable stress on anhedonia, learned helplessness, novelty suppressed feeding, time in the anxiogenic context, and entries into the anxiogenic context. Although the interpretations are limited, these findings suggest that with further investigation, cannabinoids may be a viable long-term treatment for stress-related psychopathologies such as depression.”

https://pubmed.ncbi.nlm.nih.gov/35641487/

https://www.nature.com/articles/s41398-022-01967-1