Does cannabidiol have a role in the treatment of schizophrenia?

“Schizophrenia is a debilitating psychiatric disorder which places a significant emotional and economic strain on the individual and society-at-large. Unfortunately, currently available therapeutic strategies do not provide adequate relief and some patients are treatment-resistant.

In this regard, cannabidiol (CBD), a non-psychoactive constituent of Cannabis sativa, has shown significant promise as a potential antipsychotic for the treatment of schizophrenia.

However, there is still considerable uncertainty about the mechanism of action of CBD as well as the brain regions which are thought to mediate its putative antipsychotic effects. We argue that further research on CBD is required to fast-track its progress to the clinic and in doing so, we may generate novel insights into the neurobiology of schizophrenia.”

http://www.ncbi.nlm.nih.gov/pubmed/27374322

Identification of Psychoactive Degradants of Cannabidiol in Simulated Gastric and Physiological Fluid

“The flowering plants of the genus Cannabis, which mainly comprises the sativa and indica species, have been recognized for medical treatment for millennia.

Although Cannabis contains nearly 500 compounds from 18 chemical classes, its physiological effects derive mainly from a family of naturally occurring compounds known as plant cannabinoids or phytocannabinoids. Of the more than 100 phytocannabinoids that have been identified in Cannabis, among the most important and widely studied are its main psychoactive constituent, Δ9-tetrahydrocannabinol (Δ9-THC), and the most important nonpsychoactive component, cannabidiol (CBD). Other biologically active phytocannabinoids that have been isolated in Cannabis include Δ8-THC, cannabinol, Δ9-tetrahydrocannabivarin, and cannabidivarin.

In recent research, orally administered cannabidiol (CBD) showed a relatively high incidence of somnolence in a pediatric population. Previous work has suggested that when CBD is exposed to an acidic environment, it degrades to Δ9-tetrahydrocannabinol (THC) and other psychoactive cannabinoids. To gain a better understanding of quantitative exposure, we completed an in vitro study by evaluating the formation of psychoactive cannabinoids when CBD is exposed to simulated gastric fluid (SGF).

SGF converts CBD into the psychoactive components Δ9-THC and Δ8-THC. The first-order kinetics observed in this study allowed estimated levels to be calculated and indicated that the acidic environment during normal gastrointestinal transit can expose orally CBD-treated patients to levels of THC and other psychoactive cannabinoids that may exceed the threshold for a physiological response. Delivery methods that decrease the potential for formation of psychoactive cannabinoids should be explored.

Despite persistent challenges with dosing and administration, CBD-based therapies have a good safety profile and a potential for efficacy in the treatment of a variety of medical conditions. The rapidly evolving sciences of drug delivery and cannabinoid pharmacology may soon lead to breakthroughs that will improve access to the benefits of this pharmacological class of agents. In addition, current technologies, such as transdermal-based therapy, may be able to eliminate the potential for psychotropic effects due to this acid-catalyzed cyclization by delivering CBD through the skin and into the neutral, nonreactive environment of the systemic circulation.”

http://online.liebertpub.com/doi/10.1089/can.2015.0004

Report of a parent survey of cannabidiol-enriched cannabis use in pediatric treatment-resistant epilepsy

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“Severe childhood epilepsies are characterized by frequent seizures, neurodevelopmental delays and impaired quality of life. In these treatment-resistant epilepsies, families often seek alternative treatments.

This survey explored the use of cannabidiol-enriched cannabis in children with treatment-resistant epilepsy. The survey was presented to parents belonging to a Facebook group dedicated to sharing information about the use of cannabidiol-enriched cannabis to treat their child’s seizures.

Nineteen responses met the inclusion criteria for the study: a diagnosis of epilepsy and current use of cannabidiol-enriched cannabis. Thirteen children had Dravet syndrome, four had Doose syndrome, and one each had Lennox-Gastaut syndrome and idiopathic epilepsy.

The average number of anti-epileptic drugs (AEDs) tried before using cannabidiol-enriched cannabis was 12. Sixteen (84%) of the 19 parents reported a reduction in their child’s seizure frequency while taking cannabidiol-enriched cannabis. Of these, two (11%) reported complete seizure freedom, eight (42%) reported a greater than 80% reduction in seizure frequency, and six (32%) reported a 25-60% seizure reduction.

Other beneficial effects included increased alertness, better mood and improved sleep. Side effects included drowsiness and fatigue.

Our survey shows that parents are using cannabidiol-enriched cannabis as a treatment for children with treatment-resistant epilepsy. Because of the increasing number of states that allow access to medical cannabis, its use will likely be a growing concern for the epilepsy community. Safety and tolerability data for cannabidiol-enriched cannabis use among children is not available. Objective measurements of a standardized preparation of pure cannabidiol are needed to determine whether it is safe, well tolerated and efficacious at controlling seizures in this difficult-to-treat pediatric population.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4157067/

Cannabidiol monotherapy for treatment-resistant schizophrenia

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“Cannabidiol (CBD), one of the major products of the marijuana plant, is devoid of marijuana’s typical psychological effects. In contrast, potential antipsychotic efficacy has been suggested based on preclinical and clinical data.

In this report, we further investigated the efficacy and safety of CBD monotherapy in three patients with treatment-resistant schizophrenia (TRS).

Efficacy, tolerability and side effects were assessed.

All patients tolerated CBD very well and no side effects were reported.

These preliminary data suggest that CBD monotherapy may not be effective for TRS.”

http://jop.sagepub.com/content/20/5/683.short

Cannabidiol Modulates Fear Memory Formation through Interactions with Serotonergic Transmission in the Mesolimbic System.

“Emerging evidence suggests that the largest phytochemical component of cannabis, cannabidiol (CBD), may possess pharmacotherapeutic properties in the treatment of neuropsychiatric disorders.

CBD has been reported to functionally interact with both the mesolimbic dopamine (DA) and serotonergic (5-HT) receptor systems.

Our findings demonstrate a novel NAcVTA circuit responsible for the behavioral and neuronal effects of CBD within the mesolimbic system via functional interactions with serotonergic 5-HT1A receptor signalling.”

http://www.ncbi.nlm.nih.gov/pubmed/27296152

Treatment of Dravet Syndrome.

“Dravet syndrome is among the most challenging electroclinical syndromes. There is a high likelihood of recurrent status epilepticus; seizures are medically refractory; and patients have multiple co-morbidities, including intellectual disability, behaviour and sleep problems, and crouch gait. Additionally, they are at significant risk of sudden unexplained death.

This review will focus predominantly on the prophylactic medical management of seizures, addressing both first-line therapies (valproate and clobazam) as well as second-line (stiripentol, topiramate, ketogenic diet) or later options (levetiracetam, bromides, vagus nerve stimulation). Sodium channel agents-including carbamazepine, oxcarbazepine, phenytoin and lamotrigine-should be avoided, as they typically exacerbate seizures.

Several agents in development may show promise, specifically fenfluramine and cannabidiol, but they need further evaluation in randomized, controlled trials.

In addition to prophylactic treatment, all patients need home-rescue medication and a status epilepticus protocol that can be carried out in their local hospital. Families must be counselled on non-pharmacologic strategies to reduce seizure risk, including avoidance of triggers that commonly induce seizures (including hyperthermia, flashing lights and patterns).

In addition to addressing seizures, holistic care for a patient with Dravet syndrome must involve a multidisciplinary team that includes specialists in physical, occupational and speech therapy, neuropsychology, social work and physical medicine.”

http://www.ncbi.nlm.nih.gov/pubmed/27264138

http://www.thctotalhealthcare.com/category/dravet-syndome/

Current Status and Prospects for Cannabidiol Preparations as New Therapeutic Agents.

“There is growing pressure for states and the federal government to legalize the use of cannabis products for medical purposes in the United States.

Sixteen states have legalized (or decriminalized possession of) products high in cannabidiol (CBD) and with restricted Δ9 -tetrahydrocannabinol (Δ9 -THC) content. In most of these states, the intent is for use in refractory epileptic seizures in children, but in a few states, the indications are broader.

The objectives of this review are to provide an overview of the pharmacology and toxicology of CBD; to summarize some of the regulatory, safety, and cultural issues relevant to the further exploitation of its antiepileptic or other pharmacologic activities; and to assess the current status and prospects for clinical development of CBD and CBD-rich preparations for medical use in the United States.

Unlike Δ9 -THC, CBD elicits its pharmacologic effects without exerting any significant intrinsic activity on the cannabinoid receptors (CB1 and CB2 ), whose activation results in the psychotropic effects characteristic of Δ9 -THC, and CBD possesses several pharmacologic activities that give it a high potential for therapeutic use.

CBD exhibits antiepileptic, anxiolytic, antipsychotic, and antiinflammatory properties.

In combination with Δ9 -THC, CBD has received regulatory approvals in several European countries and is currently under study in U.S. Food and Drug Administration-registered trials in the United States.

A number of states have passed legislation to allow for the use of CBD-rich, limited Δ9 -THC-content preparations of cannabis for certain pathologic conditions. CBD is currently being studied in several clinical trials and is at different stages of clinical development for various medical indications.

Judging from clinical findings reported so far, CBD and CBD-enriched preparations have great potential utility, but uncertainties regarding sourcing, long-term safety, abuse potential, and regulatory dilemmas remain.”

http://www.ncbi.nlm.nih.gov/pubmed/27285147

Aberrant epilepsy-associated mutant Nav1.6 sodium channel activity can be targeted with cannabidiol.

“Mutations in brain isoforms of voltage-gated sodium channels have been identified in patients with distinct epileptic phenotypes. Clinically, these patients often do not respond well to classic anti-epileptics and many remain refractory to treatment.

Exogenous as well as endogenous cannabinoids have been shown to target voltage-gated sodium channels and cannabidiol has recently received attention for its potential efficacy in the treatment of childhood epilepsies.

In this study, we further investigated the ability of cannabinoids to modulate sodium currents from wild-type and epilepsy-associated mutant voltage-gated sodium channels.

These findings suggest that cannabidiol could be exerting its anticonvulsant effects, at least in part, through its actions on voltage-gated sodium channels, and resurgent current may be a promising therapeutic target for the treatment of epilepsy syndromes.”

http://www.ncbi.nlm.nih.gov/pubmed/27267376

Could cannabidiol be used as an alternative to antipsychotics?

“Schizophrenia is a mental disorder that affects close to 1% of the population. Individuals with this disorder often present signs such as hallucination, anxiety, reduced attention, and social withdrawal. Although antipsychotic drugs remain the cornerstone of schizophrenia treatment, they are associated with severe side effects.

Recently, the endocannabinoid system (ECS) has emerged as a potential therapeutic target for pharmacotherapy that is involved in a wide range of disorders, including schizophrenia.

Since its discovery, a lot of effort has been devoted to the study of compounds that can modulate its activity for therapeutic purposes.

Among them, cannabidiol (CBD), a non-psychoactive component of cannabis, shows great promise for the treatment of psychosis, and is associated with fewer extrapyramidal side effects than conventional antipsychotic drugs.

The overarching goal of this review is to provide current available knowledge on the role of the dopamine system and the ECS in schizophrenia, and to discuss key findings from animal studies and clinical trials investigating the antipsychotic potential of CBD.”

http://www.ncbi.nlm.nih.gov/pubmed/27267317

Sativex Associated With Behavioral-Relapse Prevention Strategy as Treatment for Cannabis Dependence: A Case Series.

“The current lack of pharmacological treatments for cannabis dependence warrants the use of novel approaches and further investigation of promising pharmacotherapy.

In this case series, we assessed the use of self-titrated dosages of Sativex (1:1, Δ-tetrahydrocannabinol [THC]/cannabidiol [CBD] combination) and motivational enhancement therapy and cognitive behavioral therapy (MET/CBT) for the treatment of cannabis dependence among 5 treatment-seeking community-recruited cannabis-dependent subjects.

THC/CBD metabolite concentration indicated reduced cannabis use and compliance with medication.

CONCLUSIONS:

In summary, this pilot study found that with Sativex in combination with MET/CBT reduced cannabis use while preventing increases in craving and withdrawal in the 4 participants completing the study. Further systematic exploration of Sativex as a pharmacological treatment option for cannabis dependence should be performed.”

http://www.ncbi.nlm.nih.gov/pubmed/27261670