Nabilone pharmacotherapy for cannabis dependence: A randomized, controlled pilot study

Feasibility and Tolerability of Nabilone for the Treatment of Obesity: A Randomized Controlled Pilot Trial

Introduction: In epidemiological studies, people who use cannabis have a lower prevalence of obesity. Furthermore, the endocannabinoid system is recognized as a potential target for obesity treatment and partial agonism of the cannabinoid type-1 (CB1) receptor may reduce body weight. We thus hypothesized that 12 weeks of pharmacotherapy with the partial CB1 receptor agonist nabilone would reduce body weight, relative to placebo, in adults with obesity. Methods: We conducted a randomized, double-blind, placebo-controlled pilot clinical trial that investigated the feasibility, tolerability, and efficacy of 12 weeks of treatment with nabilone compared with placebo in adults with obesity. Otherwise healthy adults aged 25-45 years with obesity were randomized in a 1:1:1 ratio to one of three parallel treatment arms: high-dose nabilone (6 mg/day), low-dose nabilone (2 mg/day), or placebo. Safety and feasibility outcomes included adverse events (AEs), number of dropouts, and medication adherence per treatment arm. Efficacy outcomes included body weight, body mass index (BMI), and waist circumference. Secondary outcomes included gut microbiome changes, blood biomarkers (e.g., glucose and insulin levels), and mood. Results: Overall, 18 participants were randomized and 15 participants received at least one dose of drug (4 high-dose arm, 5 low-dose arm, 6 placebo). The trial was terminated early due to poor tolerability of the medication (e.g., all four participants allocated to high-dose nabilone withdrew due to AEs). Only eight participants completed per protocol (four in the low-dose arm and four in the placebo arm). Using data from completers only (n = 8), we saw a significant treatment effect on body weight (p < 0.001) and BMI (p < 0.001) that appeared to be driven by greater decreases in the low-dose arm (n = 4) relative to placebo (n = 4). Based on the Bray-Curtis dissimilarity, the low-dose arm showed a greater change in the overall fecal microbiome composition compared with the placebo arm (p < 0.05). Discussion: This pilot trial found poor tolerability of nabilone pharmacotherapy (especially at 6 mg/day) for adults with obesity who had not used any cannabinoid drugs for 6 months prior to enrolment. Preliminary results suggest a possible impact of nabilone on the gut microbiome.

The differential effects of medicinal cannabis on mental health: A systematic review

The use of medicinal cannabis to improve mental health is increasing globally, both in clinical settings and through self-medication. This involves a variety of products containing ∆9-tetrahydrocannabinol (THC), cannabidiol (CBD), THC + CBD combinations, or derivatives. This review provides an up-to-date overview of the positive and negative effects of medicinal cannabis on mental health diagnoses and related symptoms of the Diagnostic and Statistical Manual of Mental Disorders 5th Edition. Searches in PubMed, PsycInfo, Embase, and the Cochrane Library (October 2023 and July 2024) identified 18,341 studies, of which 49 controlled studies from 15 different countries were included. All studies focused on treatment-seeking participants using medicinal cannabis for (symptoms of) their mental health diagnosis. Included diagnoses were anxiety disorders, tic disorders, autism spectrum disorder, attention-deficit hyperactivity disorder, obsessive-compulsive disorders, anorexia nervosa, schizophrenia, psychosis, substance use disorders, insomnia, and bipolar disorders. Varying product compositions showed different effects. Most consistently, high doses of CBD were followed by some acute relief in anxiety, while CBD + THC combinations alleviated withdrawal in cannabis use disorder and improved sleep. In clinical trials, THC was associated most with dose-dependent adverse events and, in some cases, deterioration of primary study outcomes, e.g., in psychosis. In naturalistic studies, participants who used THC reported symptom improvement following usage. Risks of bias across studies were prevalent, and no study found long-lasting medicinal effects or improvement. Overall, medicinal cannabis may provide short-term relief for certain symptoms but is not a cure or without mental health risks.

Exploring Novel Pharmacotherapy Candidates for Cannabis Use Disorder: Uncovering Promising Agents on the Horizon by Mechanism of Action

With rapid expansion of cannabis legalization worldwide, rates of cannabis use and cannabis use disorder (CUD) are increasing; the need for safe and effective medications to treat CUD is urgent. This narrative review evaluates evidence for promising pharmacotherapies to treat CUD from randomized, placebo-controlled trials. Pharmacotherapies for CUD are categorized based on compound targets (e.g., cannabinoid receptor 1 [CB1] agonists such as nabilone, serotonergic compounds such as bupropion, GABAergic compounds such as zolpidem) and outcomes are organized by predetermined withdrawal symptoms, cannabis craving, and cannabis relapse/use. Most promising pharmacotherapies for CUD are drugs that act on the endocannabinoid system and specifically at the CB1 receptor. Priority populations such as females, certain racial/ethnic groups, and age groups experience a different course of CUD progression, symptoms, and drug effects that are important to consider when evaluating outcomes related to CUD. Possible explanations for these disparities are explored, along with the clinical trials that explore these demographics in treating CUD with pharmacotherapies.

Unravelling the landscape of Cannabis craving pharmacological treatments: a PRISMA-guided review of evidence

Currently, few treatments are available for craving in general, and none of them have received approval for cannabis craving. The objective of this review is to evaluate existing studies analysing treatments for cannabis craving and explore novel treatment possibilities for these patients. The study followed PRISMA guidelines and conducted an extensive database search. Inclusion criteria included human randomised controlled trials examining drug effects on craving symptoms. Exclusion criteria involved studies unrelated to craving, non-pharmacological treatments, duplicates, and non-English/Spanish/Portuguese articles. Our included 22 studies that investigated a wide range of compounds used for cravings related to other drugs, as well as interventions based on healthcare professionals' empirical knowledge. The current pharmacological treatments largely involve off-label drug use and the utilisation of cannabinoid-based medications, such as combinations of THC and lofexidine, oxytocin, progesterone, and N-acetylcysteine. These emerging treatments show promise and have the potential to revolutionise current clinical practices, but further investigation is needed to establish their efficacy. In this context, it is essential to consider non-pharmacological interventions, such as psychotherapy and behavioural treatments. These approaches play a crucial role in complementing pharmacological interventions and addressing the complex nature of the disorder.

Beyond monoamines: II. Novel applications for PET imaging in psychiatric disorders

Early applications of positron emission tomography (PET) in psychiatry sought to identify derangements of cerebral blood flow and metabolism. The need for more specific neurochemical imaging probes was soon evident, and these probes initially targeted the sites of action of neuroleptic (dopamine D₂ receptors) and psychoactive (serotonin receptors) drugs. For nearly 30 years, the centrality of monoamine dysfunction in psychiatric disorders drove the development of an armamentarium of monoaminergic PET radiopharmaceuticals and imaging methodologies. However, continued investments in monoamine-enhancing drug development realized only modest gains in efficacy and tolerability. As patent protection for many widely prescribed and profitable psychiatric drugs lapsed, drug development pipelines shifted away from monoamines in search of novel targets with the promises of improved efficacy, or abandoned altogether. Over this period, PET radiopharmaceutical development activities closely parallelled drug development priorities, resulting in the development of new PET imaging agents for non-monoamine targets. In part two of this review, we survey clinical research studies using the novel targets and radiotracers described in part one across major psychiatric application areas such as substance use disorders, anxiety disorders, eating disorders, personality disorders, mood disorders, and schizophrenia. Important limitations of the studies described are discussed, as well as key methodologic issues, challenges to the field, and the status of clinical trials seeking to exploit these targets for novel therapeutics.

Review: Cannabinoids as Medicinals

PURPOSE OF REVIEW

There have been many debates, discussions, and published writings about the therapeutic value of cannabis plant and the hundreds of cannabinoids it contains. Many states and countries have attempted, are attempting, or have already passed bills to allow legal use of cannabinoids, especially cannabidiol (CBD), as medicines to treat a wide range of clinical conditions without having been approved by a regulatory body. Therefore, by using PubMed and Google Scholar databases, we have reviewed published papers during the past 30 years on cannabinoids as medicines and comment on whether there is sufficient clinical evidence from well-designed clinical studies and trials to support the use of CBD or any other cannabinoids as medicines.

RECENT FINDINGS

Current research shows that CBD and other cannabinoids currently are not ready for formal indications as medicines to treat a wide range of clinical conditions as promoted except for several exceptions including limited use of CBD for treating two rare forms of epilepsy in young children and CBD in combination with THC for treating multiple-sclerosis-associated spasticity.

SUMMARY

Research indicates that CBD and several other cannabinoids have potential to treat multiple clinical conditions, but more preclinical, and clinical studies and clinical trials, which follow regulatory guidelines, are needed to formally recommend CBD and other cannabinoids as medicines.

Review: Cannabinoids as Medicinals

Purpose of review

There have been many debates, discussions, and published writings about the therapeutic value of cannabis plant and the hundreds of cannabinoids it contains. Many states and countries have attempted, are attempting, or have already passed bills to allow legal use of cannabinoids, especially cannabidiol (CBD), as medicines to treat a wide range of clinical conditions without having been approved by a regulatory body. Therefore, by using PubMed and Google Scholar databases, we have reviewed published papers during the past 30 years on cannabinoids as medicines and comment on whether there is sufficient clinical evidence from well-designed clinical studies and trials to support the use of CBD or any other cannabinoids as medicines.

Recent findings

Current research shows that CBD and other cannabinoids currently are not ready for formal indications as medicines to treat a wide range of clinical conditions as promoted except for several exceptions including limited use of CBD for treating two rare forms of epilepsy in young children and CBD in combination with THC for treating multiple-sclerosis-associated spasticity.

Summary

Research indicates that CBD and several other cannabinoids have potential to treat multiple clinical conditions, but more preclinical, and clinical studies and clinical trials, which follow regulatory guidelines, are needed to formally recommend CBD and other cannabinoids as medicines.

Medical cannabinoids: a pharmacology-based systematic review and meta-analysis for all relevant medical indications

BACKGROUND

Medical cannabinoids differ in their pharmacology and may have different treatment effects. We aimed to conduct a pharmacology-based systematic review (SR) and meta-analyses of medical cannabinoids for efficacy, retention and adverse events.

METHODS

We systematically reviewed (registered at PROSPERO: CRD42021229932) eight databases for randomized controlled trials (RCTs) of dronabinol, nabilone, cannabidiol and nabiximols for chronic pain, spasticity, nausea /vomiting, appetite, ALS, irritable bowel syndrome, MS, Chorea Huntington, epilepsy, dystonia, Parkinsonism, glaucoma, ADHD, anorexia nervosa, anxiety, dementia, depression, schizophrenia, PTSD, sleeping disorders, SUD and Tourette. Main outcomes and measures included patient-relevant/disease-specific outcomes, retention and adverse events. Data were calculated as standardized mean difference (SMD) and ORs with confidence intervals (CI) via random effects. Evidence quality was assessed by the Cochrane Risk of Bias and GRADE tools.

RESULTS

In total, 152 RCTs (12,123 participants) were analysed according to the type of the cannabinoid, outcome and comparator used, resulting in 84 comparisons. Significant therapeutic effects of medical cannabinoids show a large variability in the grade of evidence that depends on the type of cannabinoid. CBD has a significant therapeutic effect for epilepsy (SMD - 0.5[CI - 0.62, - 0.38] high grade) and Parkinsonism (- 0.41[CI - 0.75, - 0.08] moderate grade). There is moderate evidence for dronabinol for chronic pain (- 0.31[CI - 0.46, - 0.15]), appetite (- 0.51[CI - 0.87, - 0.15]) and Tourette (- 1.01[CI - 1.58, - 0.44]) and moderate evidence for nabiximols on chronic pain (- 0.25[- 0.37, - 0.14]), spasticity (- 0.36[CI - 0.54, - 0.19]), sleep (- 0.24[CI - 0.35, - 0.14]) and SUDs (- 0.48[CI - 0.92, - 0.04]). All other significant therapeutic effects have either low, very low, or even no grade of evidence. Cannabinoids produce different adverse events, and there is low to moderate grade of evidence for this conclusion depending on the type of cannabinoid.

CONCLUSIONS

Cannabinoids are effective therapeutics for several medical indications if their specific pharmacological properties are considered. We suggest that future systematic studies in the cannabinoid field should be based upon their specific pharmacology.

Helpful or Harmful? The Therapeutic Potential of Medications with Varying Degrees of Abuse Liability in the Treatment of Substance Use Disorders

Purpose of Review

This review summarizes recent clinical trial research on pharmacological treatments for substance use disorders, with a specific focus on agents with potential abuse liability.

Recent Findings

Pharmacological treatments for substance use disorders may include gabapentinoids, baclofen, modafinil, ketamine, cannabinoids, gamma-hydroxybutyrate, and psychedelics. Gabapentinoids may decrease negative subjective effects of withdrawal in alcohol and cannabis use disorders. Cannabinoids similarly appear to decrease use and withdrawal symptoms in cannabis use disorder, while research shows stimulant medications may reduce cravings and increase abstinence in cocaine use disorder. Ketamine and psychedelics may help treat multiple substance use disorders. Ketamine may reduce withdrawal symptoms, promote abstinence, and diminish cravings in alcohol and cocaine use disorders and psychedelics may promote remission, decrease use, and reduce cravings in alcohol and opioid use disorders.

Summary

Regardless of current regulatory approval statuses and potentials for abuse, multiple agents should not be dismissed prematurely as possible treatments for substance use disorders. However, further clinical research is needed before effective implementation can begin in practice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40429-022-00432-9.

Clinical management of cannabis withdrawal

BACKGROUND AND AIMS

Cannabis withdrawal is a well-characterized phenomenon that occurs in approximately half of regular and dependent cannabis users after abrupt cessation or significant reductions in cannabis products that contain Δ⁹ -tetrahydrocannabinol (THC). This review describes the diagnosis, prevalence, course and management of cannabis withdrawal and highlights opportunities for future clinical research.

METHODS

Narrative review of literature.

RESULTS

Symptom onset typically occurs 24-48 hours after cessation and most symptoms generally peak at days 2-6, with some symptoms lasting up to 3 weeks or more in heavy cannabis users. The most common features of cannabis withdrawal are anxiety, irritability, anger or aggression, disturbed sleep/dreaming, depressed mood and loss of appetite. Less common physical symptoms include chills, headaches, physical tension, sweating and stomach pain. Despite limited empirical evidence, supportive counselling and psychoeducation are the first-line approaches in the management of cannabis withdrawal. There are no medications currently approved specifically for medically assisted withdrawal (MAW). Medications have been used to manage short-term symptoms (e.g. anxiety, sleep, nausea). A number of promising pharmacological agents have been examined in controlled trials, but these have been underpowered and positive findings not reliably replicated. Some (e.g. cannabis agonists) are used 'off-label' in clinical practice. Inpatient admission for MAW may be clinically indicated for patients who have significant comorbid mental health disorders and polysubstance use to avoid severe complications.

CONCLUSIONS

The clinical significance of cannabis withdrawal is that its symptoms may precipitate relapse to cannabis use. Complicated withdrawal may occur in people with concurrent mental health and polysubstance use.

Eye Tracking in Patients with Parkinson's Disease Treated with Nabilone-Results of a Phase II, Placebo-Controlled, Double-Blind, Parallel-Group Pilot Study

The topic of the therapeutic use of cannabinoids in Parkinson's disease (PD) is broadly discussed and frequently comes up in the outpatient clinic. So far, there are only a few randomized clinical trials assessing the effects of cannabinoids in PD. We are able to demonstrate a reduction in non-motor symptom (NMS) burden after the administration of nabilone. As impairment of attention and working memory have been described earlier as possible side effects, we assess cognitive performance using saccadic paradigms measured by an eye tracker. We do not observe a significant difference in any of the saccadic paradigms between PD patients on placebo versus those treated with nabilone. We, therefore, conclude that top-down inhibitory control is not affected by the tetrahydrocannabinol analogue. Nabilone did not significantly worsen cognitive performance and appears to be safe to use in selected PD patients who suffer from disabling NMS.

Risks and Benefits of Cannabis and Cannabinoids in Psychiatry

OBJECTIVE

The United States is in the midst of rapidly changing laws regarding cannabis. The increasing availability of cannabis for recreational and medical use requires that mental health clinicians be knowledgeable about evidence to be considered when counseling both patients and colleagues. In this review, the authors outline the evidence from randomized double-blind placebo-controlled trials for therapeutic use of cannabinoids for specific medical conditions and the potential side effects associated with acute and chronic cannabis use.

METHODS

Searches of PubMed and PsycInfo were conducted for articles published through July 2021 reporting on "cannabis" or "cannabinoids" or "medicinal cannabis." Additional articles were identified from the reference lists of published reviews. Articles that did not contain the terms "clinical trial" or "therapy" in the title or abstract were not reviewed. A total of 4,431 articles were screened, and 841 articles that met criteria for inclusion were reviewed by two or more authors.

RESULTS

There are currently no psychiatric indications approved by the U.S. Food and Drug Administration (FDA) for cannabinoids, and there is limited evidence supporting the therapeutic use of cannabinoids for treatment of psychiatric disorders. To date, evidence supporting cannabinoid prescription beyond the FDA indications is strongest for the management of pain and spasticity.

CONCLUSIONS

As cannabinoids become more available, the need for an evidence base adequately evaluating their safety and efficacy is increasingly important. There is considerable evidence that cannabinoids have a potential for harm in vulnerable populations such as adolescents and those with psychotic disorders. The current evidence base is insufficient to support the prescription of cannabinoids for the treatment of psychiatric disorders.

Cannabinoids in the Treatment of Cannabis Use Disorder: Systematic Review of Randomized Controlled Trials

BACKGROUND

The prevalence of cannabis use and cannabis use disorders (CUD) has significantly increased over time. However, there are no approved pharmacological treatments for CUD. The aim of this study was to determine the efficacy and safety of various medical cannabinoids in the treatment of CUD.

METHODS

We conducted a systematic review of randomized controlled trials which evaluated the therapeutic potential of medical cannabinoids in individuals with CUD and summarized the main study outcomes in terms of cannabis use, abstinence, withdrawal symptoms, craving, retention in treatment and adverse events.

RESULTS

We identified eight trials with a total of 667 study participants. Dronabinol reduced cannabis withdrawal symptoms whereas nabiximols, cannabidiol and PF-04457845, a fatty acid amide inhibitor, also reduced cannabis use and improved abstinence, compared to placebo. Nabilone failed to demonstrate efficacy in the treatment of CUD. All medications were well-tolerated.

CONCLUSIONS

Cannabinoid receptor agonists, i.e., dronabinol and nabilone, showed only limited or no therapeutic potential in the treatment of CUD. In contrast, modulators of endocannabinoid activity, i.e., nabiximols, cannabidiol and PF-04457845, demonstrated broader efficacy which covered almost all aspects of CUD. Endocannabinoid modulation appears to be a promising treatment approach in CUD, but the evidence to support this strategy is still small and future research in this direction is needed.

Cannabinoids for the treatment of cannabis use disorder: New avenues for reaching and helping youth?

Cannabis use peaks during adolescence and emerging adulthood, and cannabis use disorder (CUD) is associated with a wide range of adverse outcomes. This is particularly pertinent in youth, because the developing brain may be more vulnerable to adverse effects of frequent cannabis use. Combining evidence-based psychosocial interventions with safe and effective pharmacotherapy is a potential avenue to improve youth outcomes, but we lack approved CUD pharmacotherapies. Here, we review new potential avenues for helping youth with CUD, with a particular focus on cannabinoid-based treatments. Evidence from placebo-controlled RCTs suggests synthetic delta-9-tetrahydrocannabinol (THC) decreases withdrawal symptoms, but not cannabis use, in adults with daily cannabis use/CUD, while findings regarding formulations containing THC combined with cannabidiol (CBD) are mixed. Preliminary evidence from two placebo-controlled RCTs in adults with CUD suggests that both Fatty Acid Amide Hydrolase inhibitors and CBD can reduce cannabis use. However, larger trials are needed to strengthen the evidence. Findings from adults point to cannabinoid-based treatments as a potential strategy that should be examined in youth with CUD.

Pharmacotherapies for cannabis use disorder: A systematic review and network meta-analysis

OBJECTIVE

This study aimed to determine the efficacy and acceptability of pharmacotherapies for cannabis use disorder (CUD).

METHODS

We conducted a systematic review and frequentist network meta-analysis, searching five electronic databases for randomized placebo-controlled trials of individuals diagnosed with CUD receiving pharmacotherapy with or without concomitant psychotherapy. Primary outcomes were the reduction in cannabis use and retention in treatment. Secondary outcomes were adverse events, discontinuation due to adverse events, total abstinence, withdrawal symptoms, cravings, and CUD severity. We applied a frequentist, random-effects Network Meta-Analysis model to pool effect sizes across trials using standardized mean differences (SMD, g) and rate ratios (RR) with their 95% confidence intervals.

RESULTS

We identified a total of 24 trials (n=1912, 74.9% male, mean age 30.2 years). Nabilone (d=-4.47 [-8.15; -0.79]), topiramate (d=-3.80 [-7.06; -0.54]), and fatty-acid amyl hydroxylase inhibitors (d=-2.30 [-4.75; 0.15]) reduced cannabis use relative to placebo. Dronabinol improved retention in treatment (RR=1.27 [1.02; 1.57]), while topiramate worsened treatment retention (RR=0.62 [0.42; 0.91]). Gabapentin reduced cannabis cravings (d=-2.42 [-3.53; -1.32], while vilazodone worsened craving severity (d=1.69 [0.71; 2.66]. Buspirone (RR=1.14 [1.00; 1.29]), venlafaxine (RR=1.78 [1.40; 2.26]), and topiramate (RR=9.10 [1.27; 65.11]) caused more adverse events, while topiramate caused more dropouts due to adverse events.

CONCLUSIONS

Based on this review, some medications appeared to show promise for treating individual aspects of CUD. However, there is a lack of robust evidence to support any particular pharmacological treatment. There is a need for additional studies to expand the evidence base for CUD pharmacotherapy. While medication strategies may become an integral component for CUD treatment one day, psychosocial interventions should remain the first line given the limitations in the available evidence.

The synthetic CB1 cannabinoid receptor selective agonists: Putative medical uses and their legalization

More than 500 molecules have been identified as components of Cannabis sativa (C. sativa), of which the most studied is Δ⁹-tetrahydrocannabinol (Δ⁹-THC). Several studies have suggested that Δ⁹-THC exerts diverse biological effects, ranging from fragmentation of DNA to behavioral disruptions. Currently, it is accepted that most of the pharmacological properties of Δ⁹-THC engage the activation of the cannabinoid receptors, named CB₁ and CB₂. Interestingly, multiple pieces of evidence have suggested that the cannabinoid receptors play an active role in the modulation of several diseases leading to the design of synthetic cannabinoid-like compounds. Advances in the development of synthetic CB₁ cannabinoid receptor selective agonists as therapeutical approaches are, however, limited. This review focuses on available evidence searched in PubMed regarding the synthetic CB₁ cannabinoid receptor selective agonists such as AM-1235, arachidonyl-2' chloroethylamide (ACEA), CP 50,556-1 (Levonantradol), CP-55,940, HU-210, JWH-007, JWH-018, JWH-200 (WIN 55,225), methanandamide, nabilone, O-1812, UR-144, WIN 55,212-2, nabiximols, and dronabinol. Indeed, it would be ambitious to describe all available evidence related to the synthetic CB₁ cannabinoid receptor selective agonists. However, and despite the positive evidence on the positive results of using these compounds in experimental models of health disturbances and preclinical trials, we discuss evidence in regards some concerns due to side effects.

Potential therapeutic benefits of cannabinoid products in adult psychiatric disorders: A systematic review and meta-analysis of randomised controlled trials

The utility of cannabinoids and cannabinoid-based products (CBPs) as a pharmacological aid to treat psychiatric disorders in adulthood is still poorly understood despite a number of comprehensive general reviews discussing the topic. With a focus on randomized controlled trial (RCT) data, this review and meta-analysis aimed to aggregate and evaluate all current high-quality (Level-1) research that specifically assessed the effectiveness of a CBP on a diagnosed adult psychiatric disorder. The following databases, from their inception to September 2020, were included in the search: Academic Search Premier, PubMed, Ovid MEDLINE®, Web of Science™, PsycARTICLES, PsycINFO, CINAHL (Nursing and Allied Health), and Scopus. Risk of bias for each study was individually assessed using the revised Cochrane tool. Of the 2397 papers identified, thirty-one RCTs met criteria for inclusion: ten trials focused on treating cannabis use disorder, six on schizophrenia, five on opioid/tobacco use disorder, three on anxiety disorders, two on Tourette's disorder, two on anorexia nervosa, and one trial each for attention-deficit/hyperactivity disorder, posttraumatic stress disorder, and obsessive compulsive disorder. This review finds limited evidence for the effectiveness of CBPs to acutely treat a narrow range of psychiatric symptoms. We report no evidence supporting the mid- to long-range effectiveness of any currently available CBP. In general, quality of the evidence was assessed as low- to moderate. Importantly, none of the studies discussed in this review presently endorse the use of cannabis flower as a method of treatment for any recognized psychiatric disorder. Larger, hypothesis driven RCTs are required prior to making further therapeutic recommendations.

Untapped endocannabinoid pharmacological targets: Pipe dream or pipeline?

It has been established that the endogenous cannabinoid (endocannabinoid) system plays key modulatory roles in a wide variety of pathological conditions. The endocannabinoid system comprises both cannabinoid receptors, their endogenous ligands including 2-arachidonoylglycerol (2-AG), N-arachidonylethanolamine (anandamide, AEA), and enzymes that regulate the synthesis and degradation of endogenous ligands which include diacylglycerol lipase alpha (DAGL-α), diacylglycerol lipase beta (DAGL-β), fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL), α/β hydrolase domain 6 (ABHD6). As the endocannabinoid system exerts considerable involvement in the regulation of homeostasis and disease, much effort has been made towards understanding endocannabinoid-related mechanisms of action at cellular, physiological, and pathological levels as well as harnessing the various components of the endocannabinoid system to produce novel therapeutics. However, drug discovery efforts within the cannabinoid field have been slower than anticipated to reach satisfactory clinical endpoints and raises an important question into the validity of developing novel ligands that therapeutically target the endocannabinoid system. To answer this, we will first examine evidence that supports the existence of an endocannabinoid system role within inflammatory diseases, neurodegeneration, pain, substance use disorders, mood disorders, as well as metabolic diseases. Next, this review will discuss recent clinical studies, within the last 5 years, of cannabinoid compounds in context to these diseases. We will also address some of the challenges and considerations within the cannabinoid field that may be important in the advancement of therapeutics into the clinic.

Evidence for the Endocannabinoid System as a Therapeutic Target in the Treatment of Cannabis Use Disorder

Purpose of Review

Cannabis use disorder (CUD) is highly prevalent. Psychotherapy alone is not adequately effective, with few individuals achieving abstinence. Pharmacotherapeutic supplementation may improve efficacy, and the endocannabinoid system presents a target specifically dysregulated by heavy cannabis use. This review compiles current literature evaluating endocannabinoid modulation as a treatment strategy for CUD, with implications for future research.

Recent Findings

Cannabinoid receptor agonists have been found to reduce cannabis withdrawal symptoms without a notable effect on relapse, and antagonists can produce severe psychiatric symptoms. Fatty acid amide hydrolase inhibitors and cannabidiol demonstrate the most promising efficacy in treating CUD thus far, but research with these compounds is still preliminary.

Summary

Components of the endocannabinoid system may serve as unique treatment targets with differential efficacy for the treatment of cannabis use disorder as a whole. Further research is needed exploring novel methods for targeting endocannabinoid dysfunction in CUD.

Cannabis use and cannabis use disorder

Cannabis use disorder (CUD) is an underappreciated risk of using cannabis that affects ~10% of the 193 million cannabis users worldwide. The individual and public health burdens are less than those of other forms of drug use, but CUD accounts for a substantial proportion of persons seeking treatment for drug use disorders owing to the high global prevalence of cannabis use. Cognitive behavioural therapy, motivational enhancement therapy and contingency management can substantially reduce cannabis use and cannabis-related problems, but enduring abstinence is not a common outcome. No pharmacotherapies have been approved for cannabis use or CUD, although a number of drug classes (such as cannabinoid agonists) have shown promise and require more rigorous evaluation. Treatment of cannabis use and CUD is often complicated by comorbid mental health and other substance use disorders. The legalization of non-medical cannabis use in some high-income countries may increase the prevalence of CUD by making more potent cannabis products more readily available at a lower price. States that legalize medical and non-medical cannabis use should inform users about the risks of CUD and provide information on how to obtain assistance if they develop cannabis-related mental and/or physical health problems.

Are There Therapeutic Benefits of Cannabinoid Products in Adult Mental Illness?

A position statement developed by the Canadian Psychiatric Association's (CPA) Research Committee and approved by the CPA's Board of Directors on May 13, 2020.

Care of the Patient Using Cannabis

The past 2 decades have seen a revolution in legal access to cannabis, driven largely by activists and business interests. As a result, the population of cannabis users nationwide-especially daily users-has grown significantly. An estimated 4.5-7 million persons in the United States now meet criteria for cannabis use disorder annually. This article focuses on the effects of cannabis use, intoxication, and withdrawal while also reviewing the developmental pathways of cannabis use disorder as well as evidence-based pharmacologic and psychosocial treatments.

The state of clinical outcome assessments for cannabis use disorder clinical trials: A review and research agenda

There is considerable variability in the use of outcome measures in clinical trials for cannabis use disorder (CUD), and a lack of consensus regarding optimal outcomes may have hindered development and approval of new pharmacotherapies. The goal of this paper is to summarize an evaluation of assessment measures and clinical endpoints for CUD clinical trials, and propose a research agenda and priorities to improve CUD clinical outcome assessments. The primary recommendation is that sustained abstinence from cannabis should not be considered the primary outcome for all CUD clinical trials as it has multiple limitations. However, there are multiple challenges to the development of a reliable and valid indicator of cannabis reduction, including the lack of a standard unit of measure for the various forms of cannabis and products and the limitations of currently available biological and self-report assessments. Development of a core toolkit of assessments is needed to both allow flexibility for study design, while facilitating interpretation of outcomes across trials. Four primary agenda items for future research are identified to expedite development of improved clinical outcome assessments for this toolkit: (1) determine whether minimally invasive biologic assays could identify an acute level of cannabis use associated with psychomotor impairment or other cannabis-related harms; (2) create an indicator of quantity of cannabis use that is consistent across product types; (3) examine the presence of cannabis-specific functional outcomes; and (4) identify an optimal duration to assess changes in CUD diagnostic criteria.

Pharmacotherapy for the Treatment of Cannabis Use Disorder: A Systematic Review

BACKGROUND

Cannabis use disorder (CUD) is a growing concern, and evidence-based data are needed to inform treatment options.

PURPOSE

To review the benefits and risks of pharmacotherapies for the treatment of CUD.

DATA SOURCES

MEDLINE, PsycINFO, Cochrane Database of Systematic Reviews, and clinical trial registries from inception through September 2019.

STUDY SELECTION

Pharmacotherapy trials of adults or adolescents with CUD that targeted cannabis abstinence or reduction, treatment retention, withdrawal symptoms, and other outcomes.

DATA EXTRACTION

Data were abstracted by 1 investigator and confirmed by a second. Study quality was dually assessed, and strength of evidence (SOE) was determined by consensus according to standard criteria.

DATA SYNTHESIS

Across 26 trials, the evidence was largely insufficient. Low-strength evidence was found that selective serotonin reuptake inhibitors (SSRIs) do not reduce cannabis use or improve treatment retention. Low- to moderate-strength evidence was found that buspirone does not improve outcomes and that cannabinoids do not increase abstinence rates (moderate SOE), reduce cannabis use (low SOE), or increase treatment retention (low SOE). Across all drug studies, no consistent evidence of increased harm was found.

LIMITATIONS

Few methodologically rigorous trials have been done. Existing trials are hampered by small sample sizes, high attrition rates, and heterogeneity of concurrent interventions and outcomes assessment.

CONCLUSION

Although data on pharmacologic interventions for CUD are scarce, evidence exists that several drug classes, including cannabinoids and SSRIs, are ineffective. Because of increasing access to and use of cannabis in the general population, along with a high prevalence of CUD among current cannabis users, an urgent need exists for more research to identify effective pharmacologic treatments.

PRIMARY FUNDING SOURCE

U.S. Department of Veterans Affairs. (PROSPERO: CRD42018108064).

The role of cannabis in treating anxiety: an update

PURPOSE OF REVIEW

Cannabis use for medical purposes has become increasingly common, including as treatment for mental health disorders such as anxiety. Unfortunately, the evidence examining its use in mental health has been slow to evolve, but is emerging. Given the widespread use of cannabis, it is important for both clinicians and those who suffer with anxiety to understand the effects of cannabis on symptoms of anxiety. In this review, we present recent, available evidence from animal models, clinical trials, and survey studies and evaluate the contribution of these studies to the current understanding of the role of cannabis in treating anxiety.

RECENT FINDINGS

In reviewing recent evidence, we observed significant inconsistencies across findings from preclinical studies. Large-scale surveys suggest that cannabis may be effective in reducing anxiety, however, these results stand in contrast to equivocal findings from clinical trials.

SUMMARY

The literature evaluating the efficacy of cannabis in anxiety disorders is in its infancy. The survey data is generally positive. Although, while some animal studies posit cannabis constituents to have anxiolytic effects, others suggest the opposite or null results. Few new clinical trials have been conducted recently, and the extant trials have significant flaws in methodology. Although anecdotal evidence from survey studies, and a small signal found in animal studies and single-dose clinical trials provide early support that cannabis may be effective for alleviating anxiety, ultimately, the current evidence is equivocal. More high-quality clinical trials must be published before sound conclusions regarding the efficacy of cannabis for treating anxiety can be drawn.

Persistence of use of prescribed cannabinoid medicines in Manitoba, Canada: a population-based cohort study

BACKGROUND AND AIMS

To estimate prevalence of continuous use (persistence) of prescribed cannabinoid medications for up to 1 year from initial prescription in Manitoba, Canada and predictors of duration of use.

DESIGN AND SETTING

A retrospective, population-based, cohort study using administrative data from the Manitoba Population Research Data Repository located at the Manitoba Centre for Health Policy, Canada.

PARTICIPANTS

People without a record of a previous prescription who were prescribed a cannabinoid medication from 1 April 2004 to 1 April 2016 followed for 1 year from the date of first prescription.

MEASUREMENTS

Continuous prescribed cannabinoid medication use was defined as use without a gap exceeding 60 days between prescriptions. The primary outcome was prevalence of continuous prescribed cannabinoid medication use for up to 1 year. A secondary outcome was duration of continuous use. Predictors were socio-demographic characteristics, medical diagnoses and type of cannabinoid medication.

FINDINGS

Among 5452 new users, 18.1% [95% confidence interval (CI) = 17.08-19.12] were still using cannabinoids at 1 year. Median duration of use was 31 days [interquartile range (IQR) = 25-193]. This was highest for nabilone (33 days, IQR = 25-199) and lowest for nabiximols (20 days, IQR = 7-30). Use was longest among 19-45- and 46-64-year-old users and those with the highest socio-economic status. Fibromyalgia [hazard ratio (HR) = 0.89, 95% CI = 0.84-0.95], osteoarthritis (HR = 0.91, 95% CI = 0.82-0.97) and substance use disorder (HR = 0.85, 95% CI = 0.76-0.94) diagnoses were associated with longer use (HR for discontinuation-HR < 1 less discontinuation and longer use). A diagnosis of cancer was associated with shorter use (HR = 2.73, 95% CI = 2.02-3.67).

CONCLUSIONS

In Manitoba, Canada approximately 18% of people prescribed cannabinoid medication continue using for at least 1 year. Duration of use varies with type of cannabinoid medication, age, socio-economic status and dagnosis.

A cross-sectional examination of choice and behavior of veterans with access to free medicinal cannabis

Background: With a rise in public pressure to increase veteran access to medicinal cannabis, free cannabis collectives for military veterans are proliferating across the US. Objectives: The aim of the current study was to document which cannabis formulations and routes of administration are chosen by veterans with increased access to cannabis, and to determine whether cannabis is being used as a substitute for other licit and illicit drugs. Method: The current study collected cross-sectional self-report data on cannabis use, cannabinoid constituent composition, primary indication of use, and substitution practices among a sample of 93 US military veterans (84.9% male) with access to free cannabis. Result: Most of the sample reported using cannabinoids as a substitute for either alcohol, tobacco, prescription medications, or illicit substances, reported that they use cannabis frequently (Modal frequency >4x/day, Modal quantity = 5 to 8 grams/week), and primarily select higher-risk cannabis formulations (i.e., high THC/low CBD, smoked). The majority of the sample reported that they use cannabis to self-treat multiple physical and mental health conditions/symptoms. Conclusions: Results of the current study suggest that military Veterans with reduced barriers to access cannabis could be making both helpful and harmful choices regarding their cannabis use. These findings suggest that more guidance on the selection of cannabis-based products in this population is warranted, particularly as barriers to medicinal cannabis access are reduced.

Cannabis and the Current State of Treatment for Cannabis Use Disorder

Although the opioid epidemic may command more national headlines, the past two decades have seen a revolution in cannabis policy driven largely by the public and by business interests. As a result, the population of cannabis users nationwide-especially of heavy users-has grown yearly. Although less visible than patients admitted to the emergency department for opioid-related overdose or to treatment for opioid use disorder, an estimated 4.5-7 million individuals in the United States are thought to meet criteria for cannabis use disorder in a given year. This article focuses on the developmental pathways of cannabis use disorder, the epidemiology of cannabis use among adolescents and adults in the context of rapidly changing state laws, and evidence-based treatment for the general psychiatrist. The authors provide an overview of pharmacological and psychosocial behavioral treatments for patients with the disorder while emphasizing aspects of clinical management unique to this patient population.

Systematic review of outcome domains and measures used in psychosocial and pharmacological treatment trials for cannabis use disorder

Cannabis use disorder (CUD) is prevalent and demand for treatment is increasing, yet few individuals engage in formal treatment and the efficacy of established interventions for CUD is modest. Existing clinical trials evaluating psychosocial and pharmacological treatments for CUD have incorporated a wide variety of measures for assessing cannabis use outcomes, including abstinence, self-reported frequency and quantity used, withdrawal, use/dependence severity, and other psychosocial outcomes. The heterogeneity of measures and outcomes has limited quantitative analyses of the comparative effectiveness of existing interventions. The purpose of this systematic review is to: 1) identify and characterize approaches for measuring cannabis use in existing CUD intervention trials, including abstinence, frequency and quantity of use, and 2) summarize measures used to assess treatment efficacy in other outcome domains (e.g., cannabis use severity, psychosocial functioning, cannabis withdrawal), and provide a platform for future research to evaluate which outcome measures are most likely to reflect treatment efficacy and clinically significant improvement in other outcome domains.

Cannabis and Mood Disorders

Purpose of review

The present review will provide an overview of the neurobiology, epidemiology, clinical impact, and treatment of cannabis use disorder (CUD) in mood disorders.

Recent findings

Patients with mood disorders including major depressive disorder (MDD) and bipolar disorder (BD) have higher rates of cannabis use, and CUD compared to the general population. Reasons for this association are not clear, nor are the putative therapeutic effects of cannabis use, or its components delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), in these illnesses. The evidence surrounding treatments for patients with this comorbidity is lacking, with more support for psychotherapeutic treatments compared with pharmacological treatments.

Summary

Cannabis use may be associated mood disorders, but more research is needed to increase our understanding of the mechanisms for this association, and to develop more effective treatments for this comorbidity.