Lithium carbonate in the management of cannabis withdrawal: a randomized placebo-controlled trial in an inpatient setting

Attenuation of cannabis withdrawal symptoms by Prosopis farcta extract, its luteolin and melatonin in mice: Involvement of brain-derived neurotrophic factor and dopamine

The aim of this study was the identification of luteolin in Prosopis farcta extract (PFE) and melatonin to evaluate its effect on THC withdrawal syndrome in mice. Luteolin was identified by high-performance liquid chromatography (HPCL). Signs of toxicity of mice in PFE and luteolin were monitored for LD50 calculation. The behavioral symptoms of THC withdrawal (stereotypies, ambulation, and inactivity time) induced by the rimonabant challenge were illustrated in THC-dependent mice receiving PFE, luteolin, and melatonin. The expression of mature BDNF (mBDNF) was evaluated by Western blot analysis. The dopamine concentrations were measured using HPLC. PFE and luteolin LD50 were 650 and 220 mg/kg, respectively. PFE (300 mg/kg), all doses of luteolin, and melatonin increased significantly the mBDNF expression and decreased the dopamine concentration. The findings suggest that PFE, luteolin, and melatonin are mighty in reducing the signs of THC withdrawal. It seems these effects were due to a decrease in dopamine concentration level and an increase in mBDNF protein expression in mice brains.

Mechanisms of cannabinoid tolerance

Cannabis has been used recreationally and medically for centuries, yet research into understanding the mechanisms of its therapeutic effects has only recently garnered more attention. There is evidence to support the use of cannabinoids for the treatment of chronic pain, muscle spasticity, nausea and vomiting due to chemotherapy, improving weight gain in HIV-related cachexia, emesis, sleep disorders, managing symptoms in Tourette syndrome, and patient-reported muscle spasticity from multiple sclerosis. However, tolerance and the risk for cannabis use disorder are two significant disadvantages for cannabinoid-based therapies in humans. Recent work has revealed prominent sex differences in the acute response and tolerance to cannabinoids in both humans and animal models. This review will discuss evidence demonstrating cannabinoid tolerance in rodents, non-human primates, and humans and our current understanding of the neuroadaptations occurring at the cannabinoid type 1 receptor (CB1R) that are responsible tolerance. CB1R expression is downregulated in tolerant animals and humans while there is strong evidence of CB1R desensitization in cannabinoid tolerant rodent models. Throughout the review, critical knowledge gaps are indicated and discussed, such as the lack of a neuroimaging probe to assess CB1R desensitization in humans. The review discusses the intracellular signaling pathways that are responsible for mediating CB1R desensitization and downregulation including the action of G protein-coupled receptor kinases, β-arrestin2 recruitment, c-Jun N-terminal kinases, protein kinase A, and the intracellular trafficking of CB1R. Finally, the review discusses approaches to reduce cannabinoid tolerance in humans based on our current understanding of the neuroadaptations and mechanisms responsible for this process.

A narrative review of outcome measures used in drug and alcohol inpatient withdrawal treatment research

ISSUES

Assessing drug and alcohol inpatient withdrawal treatment programs is important, as these represent a first step of treatment among people with alcohol and drug problems. However, there are many ways of measuring outcomes making it difficult for service providers to decide which domains and methods to use. This narrative review aims to clarify frequencies of the domains and methods used to assess withdrawal treatment outcomes.

APPROACH

We reviewed published studies that examined outcomes of inpatient drug and alcohol withdrawal treatment. The types of outcome measures used and the frequency of use were summarised.

KEY FINDINGS

The review showed that assessment of withdrawal treatment outcomes goes beyond traditional abstinence measures. Outcomes mainly focus on biological and psychological outcomes, with social outcomes rarely measured. Even within outcome domains (e.g., cravings), there were many assessment methods.

IMPLICATIONS

The review provides service providers with an outline of common outcome domains and measures. Given the importance of social functioning to recovery from alcohol and drug problems, greater emphasis on such measures is desirable. Future research could develop greater consensus on outcome measures for use in withdrawal management services to facilitate clarity around factors associated with treatment success.

CONCLUSION

Outcome assessment in withdrawal treatment goes beyond abstinence to include holistic measurement of biological, psychological and some social outcomes; but more work needs to be done to cohere the different assessment methods and broaden the scope to include social functioning.

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.

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.

Gabapentin attenuates somatic signs of precipitated THC withdrawal in mice

Cannabis is the most frequently used federally illicit substance in the United States. However, there are currently no FDA-approved pharmacotherapies to mitigate the withdrawal symptoms associated with cessation in heavy users. A promising, readily available, non-cannabinoid therapy are the gabapentinoids. Although currently approved for epilepsy and neuropathic pain, gabapentinoids are increasingly used for their "off-label" efficacy in treating various psychiatric conditions and substance abuse. Gabapentin (GBP) synergizes with cannabinoid agonism in neuropathic pain models, substitutes for Δ⁹-tetrahydrocannabinol (THC) in drug discrimination procedures, and reduced withdrawal symptoms in an outpatient clinical trial. However, there are limited data on the biological plausibility of the therapeutic action of gabapentinoids in cannabinoid withdrawal in preclinical models. The purpose of the current study was to determine the efficacy of GBP on attenuating THC withdrawal in mice, using an array of tests targeting withdrawal-induced and withdrawal-suppressed behaviors. Separate cohorts of male and female mice were administered THC (10 mg/kg, s.c.) or vehicle for 5.5 days, and withdrawal was precipitated by the CB₁ antagonist rimonabant (2 or 3 mg/kg, i.p.) on the sixth day. GBP (≥10 mg/kg) reduced somatic signs of withdrawal (i.e., paw tremors and head twitches), but had no effect in locomotor activity or conditioned place preference. GBP (50 mg/kg) also restored withdrawal-suppressed responding on a progressive ratio reinforcement schedule. However, GBP (50 mg/kg) had no effect in withdrawal-suppressed marble burying or tail suspension struggling and did not normalize the stress response induced by THC withdrawal, as indicated by plasma corticosterone. These data suggest gabapentin may be effective at treating cannabinoid withdrawal symptoms including somatic and affective symptoms but may act independently of endocrine stress activation.

Quetiapine treatment for cannabis use disorder

BACKROUND

Pharmacotherapy for cannabis use disorder (CUD) is an important unmet public health need.

METHODS

In a 12-week randomized double-blind placebo-controlled trial, the efficacy of quetiapine (300 mg nightly) for the treatment of CUD was tested in 130 outpatients. Weekly cannabis use was categorized into three groups: heavy use (5-7 days), moderate use (2-4 days) and light use (0-1 days).

RESULTS

At baseline both groups were considered heavy users (using days per week: median = 7.0; interquartile range (IQR): 6.5-7.0; daily dollar value: median = $121.4; IQR: 73.8-206.3). The week-by-treatment interaction was marginally significant (χ²(2) = 5.56, P = .06). With each week, the odds of moderate compared to heavy use significantly increased in the quetiapine group (OR=1.17, P < .0001), but not significantly in the placebo group (OR=1.05, P = .16). The odds of light versus heavy use did not significantly differ over time (P = .12). Treatment was also associated with reduced cannabis withdrawal symptoms by 10.4% each week (95% CI: 8.9-11.8). No serious adverse events occurred during the study and no evidence of development of a movement disorder was detected. Adverse effects were not significantly different between the quetiapine and placebo treatment arms.

CONCLUSIONS

The use of quetiapine to treat CUD was associated with an increased likelihood of heavy frequency use transitioning to moderate use, but not light use. The clinical significance of reductions in cannabis use, short of abstinence warrants further study.

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).

Pharmacotherapies for Cannabis Use Disorders: Clinical Challenges and Promising Therapeutic Agents

This chapter reviews pharmacotherapies that have been trialled for cannabis dependence, identifying those that warrant further research and those of little or uncertain value. A diverse range of medicines have been tested, representing a broad range of pharmacological strategies. These include tetrahydrocannabinol preparations, various types of antidepressant, anxiolytics, a glutamatergic modulator and the neuropeptide oxytocin. Cannabinoid agonists warrant further research. For the FAAH inhibitor PF-04457845, oxytocin, varenicline and gabapentin, although there is a signal to indicate further research is warranted, these medications do not yet have sufficient evidence to support clinical use, and larger, longer-term trials are needed in representative treatment-seeking populations. Special populations that warrant consideration are those with cannabis dependence and concurrent mental health conditions and those that develop dependence through therapeutic use.

Lithium Preparations in Psychiatry, Addiction Medicine and Neurology. Part II. Biochemical Mechanisms of Its Action

Lithium is the first and the lightest in the series of alkali metals, to which, in addition to lithium, two very biologically important elements – sodium and potassium, as well as trace elements rubidium and cesium, belong. Despite its formal affiliation to the group of alkali metals, lithium, like many other chemical elements of the «atypical» second period of the periodic table (for example, boron), is more similar in its chemical properties not to its counterparts in the group, but to its «diagonal brother» – magnesium. As we will show in this article, the diagonal chemical similarity between lithium and magnesium is of great importance for understanding the mechanisms of its intracellular biochemical action. At the same time, the intragroup chemical similarity of lithium with sodium and potassium is more important for understanding the mechanisms of its absorption, its distribution in the body and its excretion. Despite the 70 years that have passed since John Cade’s discovery of the antimanic effect of lithium, the mechanisms of its therapeutic action are still not completely understood. In the end, it turns out that the mechanism of the therapeutic action of lithium is extremely complex, multicomponent, unique and not imitable. Certain aspects of the mechanism of its action may be compatible with the mechanisms of action of other mood stabilizers, or with the mechanisms of action of so-called «lithium-mimetics», such as ebselen. However, no other drug to date failed to fully reproduce the biochemical effect of lithium on the body.

Pharmacotherapies for cannabis dependence

BACKGROUND

Globally, cannabis use is prevalent and widespread. There are currently no pharmacotherapies approved for treatment of cannabis use disorders.This is an update of a Cochrane Review first published in the Cochrane Library in Issue 12, 2014.

OBJECTIVES

To assess the effectiveness and safety of pharmacotherapies as compared with each other, placebo or no pharmacotherapy (supportive care) for reducing symptoms of cannabis withdrawal and promoting cessation or reduction of cannabis use.

SEARCH METHODS

We updated our searches of the following databases to March 2018: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO and Web of Science.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs involving the use of medications to treat cannabis withdrawal or to promote cessation or reduction of cannabis use, or both, in comparison with other medications, placebo or no medication (supportive care) in people diagnosed as cannabis dependent or who were likely to be dependent.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 21 RCTs involving 1755 participants: 18 studies recruited adults (mean age 22 to 41 years); three studies targeted young people (mean age 20 years). Most (75%) participants were male. The studies were at low risk of performance, detection and selective outcome reporting bias. One study was at risk of selection bias, and three studies were at risk of attrition bias.All studies involved comparison of active medication and placebo. The medications were diverse, as were the outcomes reported, which limited the extent of analysis.Abstinence at end of treatment was no more likely with Δ⁹-tetrahydrocannabinol (THC) preparations than with placebo (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.64 to 1.52; 305 participants; 3 studies; moderate-quality evidence). For selective serotonin reuptake inhibitor (SSRI) antidepressants, mixed action antidepressants, anticonvulsants and mood stabilisers, buspirone and N-acetylcysteine, there was no difference in the likelihood of abstinence at end of treatment compared to placebo (low- to very low-quality evidence).There was qualitative evidence of reduced intensity of withdrawal symptoms with THC preparations compared to placebo. For other pharmacotherapies, this outcome was either not examined, or no significant differences was reported.Adverse effects were no more likely with THC preparations (RR 1.02, 95% CI 0.89 to 1.17; 318 participants; 3 studies) or N-acetylcysteine (RR 0.94, 95% CI 0.71 to 1.23; 418 participants; 2 studies) compared to placebo (moderate-quality evidence). For SSRI antidepressants, mixed action antidepressants, buspirone and N-acetylcysteine, there was no difference in adverse effects compared to placebo (low- to very low-quality evidence).There was no difference in the likelihood of withdrawal from treatment due to adverse effects with THC preparations, SSRIs antidepressants, mixed action antidepressants, anticonvulsants and mood stabilisers, buspirone and N-acetylcysteine compared to placebo (low- to very low-quality evidence).There was no difference in the likelihood of treatment completion with THC preparations, SSRI antidepressants, mixed action antidepressants and buspirone compared to placebo (low- to very low-quality evidence) or with N-acetylcysteine compared to placebo (RR 1.06, 95% CI 0.93 to 1.21; 418 participants; 2 studies; moderate-quality evidence). Anticonvulsants and mood stabilisers appeared to reduce the likelihood of treatment completion (RR 0.66, 95% CI 0.47 to 0.92; 141 participants; 3 studies; low-quality evidence).Available evidence on gabapentin (anticonvulsant), oxytocin (neuropeptide) and atomoxetine was insufficient for estimates of effectiveness.

AUTHORS' CONCLUSIONS

There is incomplete evidence for all of the pharmacotherapies investigated, and for many outcomes the quality of the evidence was low or very low. Findings indicate that SSRI antidepressants, mixed action antidepressants, bupropion, buspirone and atomoxetine are probably of little value in the treatment of cannabis dependence. Given the limited evidence of efficacy, THC preparations should be considered still experimental, with some positive effects on withdrawal symptoms and craving. The evidence base for the anticonvulsant gabapentin, oxytocin, and N-acetylcysteine is weak, but these medications are also worth further investigation.

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.

What do we know about the pharmacotheraputic management of insomnia in cannabis withdrawal: A systematic review

BACKGROUND AND OBJECTIVES

Sleep disturbance is one of the hallmarks of cannabis withdrawal. Studies have indicated that treatment of this key symptom may facilitate abstinence. In the present paper we aim to provide a systematic review of the extant literature on pharmacological management of sleep disturbance associated with cannabis withdrawal.

METHOD

We conducted a systematic literature search across five electronic databases including PubMed, Psycinfo, MEDLINE, Cochrane review and Embase. Human studies using a pharmacological treatment for sleep disturbances associated with cannabis withdrawal were included. Review articles, case-series, open trials, posters, and editorials were excluded.

RESULTS

Seventeen publications, involving 562 participants, were included in this review. Major limitations involved small sample size, high dropout rate, methodological limitations, and heterogeneity of participants. Most of the studies were at high risk of bias, further downgrading the level of evidence. A meta-analysis was not performed due to lack of quantitative data, marked heterogeneity and low quality of the included studies.

CONCLUSION

There is not sufficient evidence for any of the reviewed treatment options. Methodological limitations in a majority of the studies rendered their findings preliminary. Of the twelve investigated pharmacological agents, Gabapentin, Lofexidine, Mirtazapine, Quetiapine, and Zolpidem showed some primary benefits for treatment of sleep difficulties associated with cannabis withdrawal; however, future prospective studies are required to confirm such results.

SCIENTIFIC SIGNIFICANCE

This review examines the current evidence for potential pharmacological options for treatment of cannabis withdrawal and associated sleep disturbance. It furthers our knowledge and provides groundwork for future research. (Am J Addict 2018;27:453-464).

Therapeutic potential of medicinal marijuana: an educational primer for health care professionals

With the proposed Canadian July 2018 legalization of marijuana through the Cannabis Act, a thorough critical analysis of the current trials on the efficacy of medicinal marijuana (MM) as a treatment option is necessary. This review is particularly important for primary care physicians whose patients may be interested in using MM as an alternative therapy. In response to increased interest in MM, Health Canada released a document in 2013 for general practitioners (GPs) as an educational tool on the efficacy of MM in treating some chronic and acute conditions. Although additional studies have filled in some of the gaps since the release of the Health Canada document, conflicting and inconclusive results continue to pose a challenge for physicians. This review aims to supplement the Health Canada document by providing physicians with a critical yet concise update on the recent advancements made regarding the efficacy of MM as a potential therapeutic option. An update to the literature of 2013 is important given the upcoming changes in legislation on the use of marijuana. Also, we briefly highlight the current recommendations provided by Canadian medical colleges on the parameters that need to be considered prior to authorizing MM use, routes of administration as well as a general overview of the endocannabinoid system as it pertains to cannabis. Lastly, we outline the appropriate medical conditions for which the authorization of MM may present as a practical alternative option in improving patient outcomes as well as individual considerations of which GPs should be mindful. The purpose of this paper is to offer physicians an educational tool that provides a necessary, evidence-based analysis of the therapeutic potential of MM and to ensure physicians are making decisions on the therapeutic use of MM in good faith.

The Current State of Pharmacological Treatments for Cannabis Use Disorder and Withdrawal

Cannabis use disorder (CUD) commonly occurs and carries a notable economic and functional burden at both individual and societal levels. While there are no clearly efficacious medication treatments for CUD, 20 years of committed and high-quality research in the human laboratory and clinical settings have resulted in medications with demonstrated effectiveness in the treatment of cannabis withdrawal, the ability to reduce cannabis use, and results that point to promising future work. The current state of pharmacology research for CUD highlights the need to consider particular characteristics of patients, such as gender, impulsivity, and severity of cannabis use, when selecting a medication in the off-label treatment of CUD or cannabis withdrawal. As a field, the body of work also exposes some areas in need of improvement in study design, selection of outcome measures, interpretation of results, and the overall process of evaluating candidate medications. Coming to a consensus as a field and addressing these gaps in future research will likely lend itself to further advances in improving the lives of patients with CUD.

Treatment of Cannabis Use Disorder: Current Science and Future Outlook

Cannabis is the most commonly used illicit substance in the United States. Rates of cannabis use and cannabis use disorder (CUD) have increased in the past decade, paralleling changes in the legal and political climate favoring legalization. Almost 20 million people 12 years or older report past-month cannabis use, and 8 million report daily or near-daily use. Concurrently, the perception that cannabis use poses a significant risk of negative consequences has decreased. Contrary to this perception, heavy cannabis use is associated with cognitive impairment, increased risk for psychotic disorders and other mental health problems, lower education attainment, and unemployment. Clinical trials of various treatments for CUD have likewise increased, focusing primarily on psychotherapy treatments, specifically motivational enhancement therapy, cognitive behavioral therapy, and contingency management. Their findings suggest that a combination of these three modalities produces the best abstinence outcomes, although abstinence rates remain modest and decline after treatment. More recently, pharmacotherapy trials have been conducted as adjunctive interventions to psychosocial treatment. N-acetylcysteine and gabapentin are two of the most promising medications, although no pharmacologic treatment has emerged as clearly efficacious. In this review, we provide a detailed summary of clinical trials that evaluated psychotherapy and pharmacotherapy for treating CUD and discuss emerging areas of clinical research and cannabis-specific barriers to treatment.

Severity of Withdrawal Symptoms, Plasma Oxytocin Levels, and Treatment Outcome in Heroin Users Undergoing Acute Withdrawal

Pre-clinical studies show that, following chronic opioid exposure, oxytocin neurons exhibit over-excitation upon withdrawal, causing an increase in oxytocin brain and plasma levels. Relevant clinical data on humans are scarce. This study investigates the opioid withdrawal stress effect on oxytocin plasma levels in humans. We evaluated 57 male chronic heroin users in a residential detoxification program. We determined plasma oxytocin levels by ELISA and measured the stress effects of withdrawal using the COWS scale for opioid withdrawal, the VAS scale for craving, and the Hamilton scales for anxiety and depression on the second day of admission. Out of the 57 patients enrolled in the study, 27 completed the 21-day program, while the remaining 30 dropped out prior to completion. Plasma oxytocin levels were significantly higher in those individuals who dropped out than in those who completed the program. Participants who dropped out at some stage scored higher in the COWS, VAS-Craving, and Hamilton-anxiety scales, indicating a higher stress and explaining the higher oxytocin levels. In addition, plasma oxytocin levels correlated positively with the scores achieved in the COWS and Hamilton-anxiety scales. Higher withdrawal stress levels are associated with higher plasma oxytocin levels and early treatment discharge.

Evidence-based Treatment Options in Cannabis Dependency

BACKGROUND

Now that the consumption of natural and synthetic cannabinoids is becoming more widespread, the specific treatment of cannabis-related disturbances is an increasingly important matter. There are many therapeutic options, and it is not always clear which ones are evidence-based and appropriate for use in a given clinical situation.

METHODS

This review is based on reports of pertinent randomized and controlled trials (RCTs) that were retrieved by a selective search in the PubMed and Cochrane databases.

RESULTS

Cognitive behavior therapy (CBT) combined with other techniques has been found to have a moderate to large effect (Cohen's d = 0.53-0.9) on the amount of cannabis consumed as well as on the level of psychosocial functioning or the dependence syndrome. Systemic multidimensional family therapy (MDFT) has been found beneficial for younger adolescents who consume large amounts of cannabis and have psychiatric comorbidities. Short-term interventions with motivational talk therapy have been found effective for patients with or without an initial desire to achieve cannabis abstinence. All of these psychotherapeutic interventions are effective at evidence level Ia. The administration of gabapentin had a weak effect (d = 0.26) on the quantity consumed and on abstinence (evidence level Ib). Withdrawal symptoms can be alleviated with cannabinoid-receptor antagonists (d = 0.223 and 0.481) (evidence level Ib). On the other hand, there is evidence that serotonergic antidepressants can worsen withdrawal manifestations and increase the likelihood of relapse.

CONCLUSION

Psychotherapeutic techniques remain the foundation of treatment for cannabis dependence. No drug has yet been approved for the treatment of cannabis dependence because of the lack of scientific evidence. The rates of abstinence that are currently achieved, even with psychotherapy, are still only moderate. Further clinical studies are needed for the evaluation of combinations of various treatments that can meet the needs of individual patients.

ABC transporters P-gp and Bcrp do not limit the brain uptake of the novel antipsychotic and anticonvulsant drug cannabidiol in mice

Cannabidiol (CBD) is currently being investigated as a novel therapeutic for the treatment of CNS disorders like schizophrenia and epilepsy. ABC transporters such as P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) mediate pharmacoresistance in these disorders. P-gp and Bcrp are expressed at the blood brain barrier (BBB) and reduce the brain uptake of substrate drugs including various antipsychotics and anticonvulsants. It is therefore important to assess whether CBD is prone to treatment resistance mediated by P-gp and Bcrp. Moreover, it has become common practice in the drug development of CNS agents to screen against ABC transporters to help isolate lead compounds with optimal pharmacokinetic properties. The current study aimed to assess whether P-gp and Bcrp impacts the brain transport of CBD by comparing CBD tissue concentrations in wild-type (WT) mice versus mice devoid of ABC transporter genes. P-gp knockout (Abcb1a/b (-∕-)), Bcrp knockout (Abcg2 (-∕-)), combined P-gp/Bcrp knockout (Abcb1a/b (-∕-) Abcg2 (-∕-)) and WT mice were injected with CBD, before brain and plasma samples were collected at various time-points. CBD results were compared with the positive control risperidone and 9-hydroxy risperidone, antipsychotic drugs that are established ABC transporter substrates. Brain and plasma concentrations of CBD were not greater in P-gp, Bcrp or P-gp/Bcrp knockout mice than WT mice. In comparison, the brain/plasma concentration ratios of risperidone and 9-hydroxy risperidone were profoundly higher in P-gp knockout mice than WT mice. These results suggest that CBD is not a substrate of P-gp or Bcrp and may be free from the complication of reduced brain uptake by these transporters. Such findings provide favorable evidence for the therapeutic development of CBD in the treatment of various CNS disorders.

Progress toward pharmacotherapies for cannabis-use disorder: an evidence-based review

Cannabis is the most widely used and variably regulated drug in the world, with increasing trends of use being reported in the US, Australia, Asia, and Africa. Evidence has shown a decrease in the age of commencement of cannabis use in some developed countries and a prolongation of risk of initiation to cannabis use beyond adolescence among more recent users. Cannabis use is associated with numerous health risks and long-term morbidity, as well as risk of developing cannabis-use disorders. Cannabis users infrequently seek professional treatment, and normally do so after a decade of use. Cannabis-use disorders are currently treated using a selection of psychosocial interventions. Severity of withdrawal is a factor that increases the risk of relapse, and is the target of pharmacotherapy studies. Currently, there is no approved pharmacotherapy for cannabis-use disorders. A number of approaches have been examined, and trials are continuing to find a safe and effective medication with little abuse liability.

Sleep abnormalities associated with alcohol, cannabis, cocaine, and opiate use: a comprehensive review

Sleep abnormalities are associated with acute and chronic use of addictive substances. Although sleep complaints associated with use and abstinence from addictive substances are widely recognized, familiarity with the underlying sleep abnormalities is often lacking, despite evidence that these sleep abnormalities may be recalcitrant and impede good outcomes. Substantial research has now characterized the abnormalities associated with acute and chronic use of alcohol, cannabis, cocaine, and opiates. This review summarizes this research and discusses the clinical implications of sleep abnormalities in the treatment of substance use disorders.

Screening Medications for the Treatment of Cannabis Use Disorder

Cannabis use has been increasingly accepted legally and in public opinion. However, cannabis has the potential to produce adverse physical and mental health effects, and cannabis use disorder (CUD) occurs in a substantial percentage of both occasional and daily cannabis users. Many people have difficulty discontinuing use despite receiving treatment. Therefore, it would be beneficial to develop safe and effective medications for treating CUD. To achieve this, methods have been developed for screening and evaluating potential medications using animal models and controlled experimental protocols in human volunteers. In this chapter, we describe: (1) animal models available for assessing the effect of potential medications on specific aspects of CUD, (2) the main findings obtained so far with these animal models, (3) the approaches used to assess potential medications in humans in laboratory experiments and clinical trials, and (4) the effectiveness of several potential pharmacotherapies on particular aspects of CUD modeled in these human studies.

The Effects of Lithium Carbonate Supplemented with Nitrazepam on Sleep Disturbance during Cannabis Abstinence

STUDY OBJECTIVE

Sleep disturbance is a hallmark feature of cannabis withdrawal. In this study we explored the effects of lithium treatment supplemented with nitrazepam on objective and subjective measures of sleep quality during inpatient cannabis withdrawal.

METHODS

Treatment-seeking cannabis-dependent adults (n = 38) were admitted for 8 days to an inpatient withdrawal unit and randomized to either oral lithium (500 mg) or placebo, twice daily in a double-blind RCT. Restricted nitrazepam (10 mg) was available on demand (in response to poor sleep) on any 3 of the 7 nights. Dependent outcome measures for analysis included repeated daily objective actigraphy and subjective sleep measures throughout the 8 day detox, subjective cannabis withdrawal ratings, and detoxification completion rates.

RESULTS

Based on actigraphy, lithium resulted in less fragmented sleep compared to placebo (p = 0.04), but no other objective measures were improved by lithium. Of the subjective measures, only nightmares were suppressed by lithium (p = 0.04). Lithium did not have a significant impact on the use of nitrazepam. Sleep bout length (p < 0.0001), sleep efficiency (p < 0.0001), and sleep fragmentation (p = 0.05) were improved on nights in which nitrazepam was used. In contrast, only night sweats improved with nitrazepam from the subjective measures (p = 0.04). A Cox regression with daily repeated measures of sleep efficiency averaged across all people in the study a predictor suggests that a one-unit increase in sleep efficiency (the ratio of total sleep time to the total time in bed expressed as a percentage) resulted in a 14.6% increase in retention in treatment (p = 0.008, Exp(B) = 0.854, 95% CI = 0.759-0.960). None of the other sleep measures, nor use of lithium or nitrazepam were significantly associated with retention in treatment.

CONCLUSIONS

Lithium seems to have only limited efficacy on sleep disturbance in cannabis withdrawal. However the nitrazepam improved several actigraphy measures of sleep disturbance, warranting further investigation. Discord between objective and subjective sleep indices suggest caution in evaluating treatment interventions with self-report sleep data only.

Endocannabinoids and the Endocrine System in Health and Disease

Some of the earliest reports of the effects of cannabis consumption on humans were related to endocrine system changes. In this review, the effects of cannabinoids and the role of the CB1 cannabinoid receptor in the regulation of the following endocrine systems are discussed: the hypothalamic-pituitary-gonadal axis, prolactin and oxytocin, thyroid hormone and growth hormone, and the hypothalamic-pituitary-adrenal axis. Preclinical and human study results are presented.