A placebo-controlled trial of buspirone for the treatment of marijuana dependence

Prevalence and Treatment of Substance Misuse in Older Adults: Beyond Early Adulthood

Substance misuse, traditionally seen as a problem of early to mid-adulthood, is becoming increasingly prevalent among the older adult population (ages ≥65). Diagnosing and treating substance misuse in this vulnerable population is challenging because of multiple pre-existing medical comorbidities as well as polypharmacy. As such, it remains underdiagnosed and underrepresented in the literature. This review provides an overview of the three most commonly misused substances in older adults: alcohol, cannabis, and prescription drugs. It examines epidemiology, societal trends, and treatment options, highlighting the need for targeted research to address the unique challenges faced by older adults. This review also briefly comments on the prevalence and treatment of other illicit drugs in this population.

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.

Monitoring adherence and abstinence of cannabis use disorder patients: Profile identification and relationship with long-term treatment outcomes

BACKGROUND

Patients with cannabis use disorder (CUD) show heterogeneous sociodemographic and consumption patterns. Although previous studies, focused on identifying subgroups of CUD patients using input variables, have yielded useful results for planning individualized treatments, no published research has analyzed the profiles of CUD patients according to their therapeutic progress. This study therefore aims to identify subgroups of patients using adherence and abstinence indicators and to explore whether these profiles are associated with sociodemographic characteristics, consumption variables, and long-term therapeutic outcomes.

METHODS

This was a retrospective observational study with a multisite sample of 2055 CUD outpatients who were beginning treatment. The study monitored patient data at two-year follow-up. We conducted latent profiles analysis on the appointment attendance ratio and percentage of negative cannabis tests.

RESULTS

A three profile solution emerged: i) moderate abstinence/moderate adherence (n = 997); ii) high abstinence/moderate adherence (n = 613); and iii) high abstinence/high adherence (n = 445). The study found the most marked differences at the beginning of treatment for education level (chi² (8) = 121.70, p < .001), source of referral (chi² (12) = 203.55, p < .001), and frequency of cannabis use (chi² (10) = 232.39, p < .001). Eighty percent of patients from the "high abstinence/high adherence" group were relapse-free at two year follow-up. This percentage decreased to 24.3 % in the "moderate abstinence/moderate adherence" group.

CONCLUSIONS

Research has shown adherence and abstinence indicators to be useful for identifying subgroups of patients with different prognoses regarding long-term success. Recognizing the sociodemographic and consumption variables associated with these profiles at the beginning of treatment could help to inform the design of more individualized interventions.

Consideration of sex and gender differences in addiction medication response

Substance use continues to contribute to significant morbidity and mortality in the United States, for both women and men, more so than another other preventable health condition. To reduce the public health burden attributable to substances, the National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism have identified that medication development for substance use disorder is a high priority research area. Furthermore, both Institutes have stated that research on sex and gender differences in substance use medication development is a critical area. The purpose of the current narrative review is to highlight how sex and gender have been considered (or not) in medication trials for substance use disorders to clarify and summarize what is known regarding sex and gender differences in efficacy and to provide direction to the field to advance medication development that is consistent with current NIH 'sex as a biological variable' (SABV) policy. To that end, we reviewed major classes of abused substances (nicotine, alcohol, cocaine, cannabis, opioids) demonstrating that, sex and gender have not been well-considered in addiction medication development research. However, when adequate data on sex and gender differences have been evaluated (i.e., in tobacco cessation), clinically significant differences in response have been identified between women and men. Across the other drugs of abuse reviewed, data also suggest sex and gender may be predictive of outcome for some agents, although the relatively low representation of women in clinical research samples limits making definitive conclusions. We recommend the incorporation of sex and gender into clinical care guidelines and improved access to publicly available sex-stratified data from medication development investigations.

Varenicline as a treatment for cannabis use disorder: A placebo-controlled pilot trial

BACKGROUND

An efficacious pharmacotherapy for cannabis use disorder (CUD) has yet to be established. This study preliminarily evaluated the safety and efficacy of varenicline for CUD in a proof-of-concept clinical trial.

METHODS

Participants in this 6-week randomized, placebo-controlled pilot trial received either varenicline (n = 35) or placebo (n = 37), added to a brief motivational enhancement therapy intervention. Outcomes included cannabis withdrawal, cannabis abstinence, urine cannabinoid levels, percent cannabis use days, and cannabis sessions per day.

RESULTS

Both treatment groups noted significant decreases in self-reported cannabis withdrawal, percentage of days used, and use sessions per day during treatment compared to baseline. While this pilot trial was not powered to detect statistically significant between-group differences, participants randomized to varenicline evidenced numerically greater rates of self-reported abstinence at the final study visit [Week 6 intent-to-treat (ITT): Varenicline: 17.1% vs. Placebo: 5.4%; RR = 3.2 (95% CI: 0.7,14.7)]. End-of-treatment urine creatinine corrected cannabinoid levels were numerically lower in the varenicline group and higher in the placebo group compared to baseline [Change from baseline: Varenicline -1.7 ng/mg (95% CI: -4.1,0.8) vs. Placebo: 1.9 ng/mg (95% CI: -0.4,4.3); Δ = 3.5 (95% CI: 0.1,6.9)]. Adverse events related to study treatment did not reveal new safety signals.

CONCLUSIONS

Findings support the feasibility of conducting clinical trials of varenicline as a candidate pharmacotherapy for CUD, and indicate that a full-scale efficacy trial, powered based on effect sizes and variability yielded in this study, is warranted.

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.

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.

Ketamine-facilitated behavioral treatment for cannabis use disorder: A proof of concept study

BACKGROUND

Sub-anesthetic ketamine infusions may benefit a range of psychiatric conditions, including alcohol and cocaine use disorders. Currently, there are no effective pharmacological treatments for cannabis use disorder.

OBJECTIVES

The objective of this uncontrolled proof of concept trial was to test the feasibility, tolerability, and potential therapeutic effects of integrating ketamine infusions with a behavioral platform of motivational enhancement therapy and mindfulness-based relapse prevention in treating cannabis use disorder (CUD).

METHODS

Eight cannabis-dependent individuals (four female, four male) receiving motivational enhancement therapy and mindfulness-based relapse prevention behavioral treatments completed this single-blind outpatient 6-week study. Participants received either one or two infusions of ketamine (0.71 mg/kg [infusion 1]; 1.41 mg/kg [infusion 2] for non-responders) during the study. Participants self-reported cannabis use (Timeline Follow-Back) and underwent an assessment of confidence in abstaining from using cannabis (Drug-Taking Confidence Questionnaire) at predetermined time points throughout the study.

RESULTS

Ketamine infusions were well-tolerated and there were no adverse events. Frequency of cannabis use decreased significantly from baseline (B = 5.1, s.e = 0.7) to the week following the first infusion (B = 0.8, s.e = 0.412), and remained reduced at the end of the study (B = 0.5, s.e = 0.3). Participants' confidence in their ability to abstain from cannabis in potentially triggering situations increased significantly from baseline to the end of study.

CONCLUSIONS

These findings suggest that combining ketamine with behavioral therapy is feasible,tolerable, and potentially helpful, in treating cannabis-dependent individuals.

Dopamine D3 receptor-based medication development for the treatment of opioid use disorder: Rationale, progress, and challenges

Opioid abuse and related overdose deaths continue to rise in the United States, contributing to the current national opioid crisis. Although several opioid-based pharmacotherapies are available (e.g., methadone, buprenorphine, naloxone), they show limited effectiveness in long-term relapse prevention. In response to the opioid crisis, the National Institute on Drug Abuse proposed a list of pharmacological targets of highest priority for medication development for the treatment of opioid use disorders (OUD). Among these are antagonists of dopamine D3 receptors (D3R). In this review, we first review recent progress in research of the dopamine hypothesis of opioid reward and abuse and then describe the rationale and recent development of D3R ligands for the treatment of OUD. Herein, an emphasis is placed on the effectiveness of newly developed D3R antagonists in the animal models of OUD. These new drug candidates may also potentiate the analgesic effects of clinically used opioids, making them attractive as adjunctive medications for pain management and treatment of OUD.

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.

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.

When and How to Treat Possible Cannabis Use Disorder

Cannabis (marijuana) is a drug product derived from the plant Cannabis sativa. Cannabinoid is a general term for all chemical constituents of the cannabis plant. Legalization of marijuana in numerous US states, the availability of cannabis of higher potency, and the emergence of synthetic cannabinoids may have contributed to increased demand for related medical services. The most effective available treatments for cannabis use disorder are psychosocial approaches. There is no pharmacotherapy approved treatment. This article reviews the current state of knowledge regarding effective treatments for cannabis use disorder.

Impact of cannabis legalization on treatment and research priorities for cannabis use disorder

An increasing proportion of the world has legalized cannabis for medicinal or recreational use. The legalization trend appears to be continuing. These changes in the legislative landscape may have important health, treatment, and research implications. This review discusses public health outcomes that may be impacted by increases in cannabis availability and use. It additionally considers potential research and treatment priorities in the face of widespread cannabis legalization.

Biological correlates of self-reported new and continued abstinence in cannabis cessation treatment clinical trials

BACKGROUND

The agreement between self-reported cannabis abstinence with urine cannabinoid concentrations in a clinical trials setting is not well characterized. We assessed the agreement between various cannabinoid cutoffs and self-reported abstinence across three clinical trials, one including contingency management for abstinence.

METHODS

Three cannabis cessation clinical trials where participants reported use and provided weekly urine samples for cannabis and creatinine concentration measurements were included. Bootstrapped data were assessed for agreement between self-reported 7+ day abstinence and urine cannabinoid tests using generalized linear mixed effects models for clustered binary outcomes. One study implemented contingency management for cannabis abstinence. Four hundred and seventy-three participants with 3787 valid urine specimens were included. Urine was analyzed for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol and creatinine using immunoassay methods Biological cutoffs of 50, 100, and 200 ng/ml, as well as changes in CN normalized THCCOOH (25%/50% decrease), were assessed for agreement with self-reported abstinence during the three clinical trials.

RESULTS

Agreement between measured THCCOOH and self-reported abstinence increases with increasing cutoff concentrations, while the agreement with self-reported non-abstinence decreases with increasing cutoff concentrations. Combining THCCOOH cutoffs with recent changes in CN-THCCOOH provides a better agreement in those self-reporting abstinence. Participants in the studies that received CM for abstinence had a lower agreement between self-reported abstinence and returned to use than those in studies that did not have a contingency management component.

CONCLUSION

Using combinations of biological measurements and self-reported abstinence, confirmation of study related abstinence may be verifiable earlier and with greater accuracy than relying on a single measurement.

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.

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

BACKGROUND AND OBJECTIVES

We assessed the safety, tolerability, and preliminary efficacy of nabilone, a cannabinoid agonist, to treat cannabis dependence.

METHODS

Eighteen adults with DSM-IV cannabis dependence were randomized to receive either 2 mg/day of nabilone (n = 10) or placebo (n = 8) for 10 weeks in addition to medication management. Twelve participants, six in each group, completed treatment. The safety and tolerability of nabilone was assessed at each visit. Any side effects from nabilone or the placebo were documented. Cannabis use outcomes were assessed via self-report of days of use and twice-weekly urine cannabinoid tests; secondary outcomes included cannabis craving and anxiety.

RESULTS

We assessed safety and tolerability at each study visit. A total of eight adverse events, all mild or moderate, were reported in two participants in the nabilone group, and six events were reported in four participants in the placebo group during study treatment. A total of eight adverse events were reported in two participants in the nabilone group and six events were reported in four participants in the placebo group during study treatment. All reported adverse events were rated mild-to-moderate. There were no side effects deemed serious enough to be classified as an FDA-defined serious adverse event. In general, participants in both groups reported reduced cannabis use according to self-report over the course of the study, although these reductions were not statistically discernible. Moreover, there was no difference in cannabis use between the nabilone group and the placebo group as measured by self-report.

DISCUSSION AND CONCLUSIONS

Nabilone pharmacotherapy was safe and well-tolerated in participants with cannabis dependence. Future studies might evaluate a higher dose of nabilone to determine its effects on cannabis use outcomes in participants with cannabis dependence.

SCIENTIFIC SIGNIFICANCE

There remains a clear need for additional pharmacotherapy trials for cannabis dependence, and nabilone remains a candidate for such trials. (Am J Addict 2017;26:795-801).

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.

Topiramate and motivational enhancement therapy for cannabis use among youth: a randomized placebo-controlled pilot study

Cannabis misuse accounts for nearly all of the substance abuse treatment admissions among youth in the United States. Most youth do not experience sustained benefit from existing psychosocial treatments; however, medication development research for treating adolescent cannabis misuse is almost nonexistent. We conducted a double-blind, placebo-controlled, pilot study to test the potential efficacy of topiramate plus motivational enhancement therapy (MET) for treating cannabis use among adolescents. Sixty-six heavy cannabis users, ages 15 to 24 years, were randomized to one of two 6-week treatment conditions: topiramate plus MET or placebo plus MET. Topiramate was titrated over 4 weeks then stabilized at 200 mg/day for 2 weeks. MET was delivered biweekly for a total of three sessions. Only 48 percent of youths randomized to topiramate completed the 6-week trial (n = 19), compared with 77 percent of youths in the placebo condition (n = 20). Adverse medication side effects were the most common reason for withdrawal among participants in the topiramate group. Latent growth models showed that topiramate was superior to placebo for reducing the number of grams smoked per use day, but it did not improve abstinence rates. The same pattern of results was found when values for missing outcomes were imputed. We show that topiramate combined with MET demonstrated efficacy for reducing how much cannabis adolescents smoked when they used but did not affect abstinence rates. The magnitude of this effect was modest, however, and topiramate was poorly tolerated by youths, which calls into question the clinical importance of these findings.

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.

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.

Marijuana dependence: not just smoke and mirrors

Marijuana (Cannabis sativa) is the most commonly used illicit drug worldwide as well as in the Unites States. Prolonged use of marijuana or repeated administration of its primary psychoactive constituent, Δ9-tetrahydrocannabinol (THC), can lead to physical dependence in humans and laboratory animals. The changes that occur with repeated cannabis use include alterations in behavioral, physiological, and biochemical responses. A variety of withdrawal responses occur in cannabis-dependent individuals: anger, aggression, irritability, anxiety and nervousness, decreased appetite or weight loss, restlessness, and sleep difficulties with strange dreams. But the long half-life and other pharmacokinetic properties of THC result in delayed expression of withdrawal symptoms, and because of the lack of contiguity between drug cessation and withdrawal responses the latter are not readily recognized as a clinically relevant syndrome. Over the past 30 years, a substantial body of clinical and laboratory animal research has emerged supporting the assertion that chronic exposure to cannabinoids produces physical dependence and may contribute to drug maintenance in cannabis-dependent individuals. However, no medications are approved to treat cannabis dependence and withdrawal. In this review, we describe preclinical and clinical research that supports the existence of a cannabinoid withdrawal syndrome. In addition, we review research evaluating potential pharmacotherapies (e.g., THC, a variety of antidepressant drugs, and lithium) to reduce cannabis withdrawal responses and examine how expanded knowledge about the regulatory mechanisms in the endocannabinoid system may lead to promising new therapeutic targets.

Vilazodone for cannabis dependence: A randomized, controlled pilot trial

BACKGROUND AND OBJECTIVES

The purpose of this study was to evaluate the efficacy of vilazodone, a selective serotonin receptor inhibitor and partial 5-HT1A agonist, for treatment of cannabis dependence.

METHODS

Seventy-six cannabis-dependent adults were randomized to receive either up to 40 mg/day of vilazodone (n = 41) or placebo (n = 35) for 8 weeks combined with a brief motivational enhancement therapy intervention and contingency management to encourage study retention. Cannabis use outcomes were assessed via weekly urine cannabinoid tests; secondary outcomes included cannabis use self-report and cannabis craving.

RESULTS

Participants in both groups reported reduced self-reported cannabis use over the course of the study; however, vilazodone provided no advantage over placebo in reducing cannabis use. Men had significantly lower creatinine-adjusted cannabinoid levels and a trend for increased negative urine cannabinoid tests than women.

DISCUSSION AND CONCLUSIONS

Vilazodone was not more efficacious than placebo in reducing cannabis use. Important gender differences were noted, with women having worse cannabis use outcomes than men.

SCIENTIFIC SIGNIFICANCE

Further medication development efforts for cannabis use disorders are needed, and gender should be considered as an important variable in future trials.

Pharmacologic management of comorbid post-traumatic stress disorder and addictions

BACKGROUND AND OBJECTIVES

Post-traumatic Stress Disorder (PTSD) and substance use disorders (SUD) frequently co-occur, and their combination can increase poor health outcomes as well as mortality.

METHODS

Using PUBMED and the list of references from key publications, this review article covered the epidemiology, neurobiology and pharmacotherapy of PTSD with comorbid alcohol, opiate, and cannabis use disorders. These SUD represent two with and one without FDA approved pharmacotherapies.

RESULTS

SUD is two to three times more likely among individuals with lifetime PTSD, and suicide, which is made more likely by both of these disorders, appears to be additively increased by having this comorbidity of SUD and PTSD. The shared neurobiological features of these two illnesses include amygdalar hyperactivity with hippocampal, medial prefrontal and anterior cingulate cortex dysfunction. Medications for comorbid PTSD and SUD include the PTSD treatment sertraline, often used in combination with anticonvulsants, antipsychotics, and adrenergic blockers. When PTSD is comorbid with alcohol use disorder (AUD), naltrexone, acamprosate or disulfiram may be combined with PTSD treatments. Disulfiram alone may treat both PTSD and AUD. For PTSD combined with opiate use disorder methadone or buprenorphine are most commonly used with sertraline. Marijuana use has been considered by some to be a treatment for PTSD, but no FDA treatment for this addiction is approved. Pregabalin and D-cycloserine are two innovations in pharmacotherapy for PTSD and SUD.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Comorbid PTSD and SUD amplifies their lethality and treatment complexity. Although they share important neurobiology, these patients uncommonly respond to a single pharmacotherapy such as sertraline or disulfiram and more typically require medication combinations and consideration of the specific type of SUD.

Buspirone treatment of cannabis dependence: A randomized, placebo-controlled trial

BACKGROUND

The purpose of this study was to evaluate the efficacy of buspirone, a partial 5-HT1A agonist, for treatment of cannabis dependence.

METHODS

One hundred seventy-five cannabis-dependent adults were randomized to receive either up to 60mg/day of buspirone (n=88) or placebo (n=87) for 12 weeks combined with a brief motivational enhancement therapy intervention and contingency management to encourage study retention. Cannabis use outcomes were assessed via weekly urine cannabinoid tests.

RESULTS

Participants in both groups reported reduced cannabis craving over the course of the study; however, buspirone provided no advantage over placebo in reducing cannabis use. Significant gender by treatment interactions were observed, with women randomized to buspirone having fewer negative urine cannabinoid tests than women randomized to placebo (p=0.007), and men randomized to buspirone having significantly lower creatinine adjusted cannabinoid levels as compared to those randomized to placebo (p=0.023). An evaluation of serotonin allelic variations did not find an association with buspirone treatment response.

CONCLUSIONS

Buspirone was not more efficacious than placebo in reducing cannabis use. Important gender differences were noted, with women having worse cannabis use outcomes with buspirone treatment. Considerations for future medication trials in this challenging population are discussed.

Pharmacological targeting of dopamine D3 receptors: Possible clinical applications of selective drugs

Dopamine D3 receptors have been pharmacologically engaged in humans since the development of the first antipsychotics and ergot-derivative dopamine (DA) agonists, even without knowing it. These agents were generally non-selective, developed primarily to target D2 receptors. In the last 10 years the understanding of the clinical implication of D3 receptors has been progressing also due to the identification of D3 gene polymorphisms, the use of more selective PET ligands such as [(11)C]-(+)-PHNO and the learning regarding the clinical use of the D3-preferential D2/D3 agonists ropinirole and pramipexole. A new specific neuroplasticity role of D3 receptor regarding dendrite arborisation outgrowth in dopaminergic neurons was also proposed to support, at least in part, the slowing of disease observed in subjects with Parkinson׳s Disease treated with DA agonists. Similar mechanisms could be at the basis of the antidepressant-like effects observed with DA agonists when co-administered with standard of care. Severe adverse event occurring with the use of anti-parkinsonian DA agonists in predisposed subjects, i.e., impulse control disorders, are now suggested to be putatively related to overactive D3 receptors. Not surprisingly, blockade of D3 receptors was proposed as treatment for addictive disorders, a goal that could be potentially achieved by repositioning buspirone, an anxiolytic drug with D3-preferential antagonistic features, or with novel selective D3 antagonists or partial agonists currently in development for schizophrenia. At the moment ABT-925 is the only selective D3 antagonist tested in schizophrenic patients in Phase II, showing an intriguing cognitive enhancing effects supported by preclinical data. Finally, exploratory pharmacogenetic analysis suggested that ABT-925 could be effective in a subpopulation of patients with a polymorphism on the D3 receptor, opening to a possible personalised medicine approach.

Cannabis and psychopathology: The meandering journey of the last decade

Since its inception cannabis has been observed to be associated with various psycho-pathology. In this paper, the authors have reviewed the advancement made in this area over the last decade. The association between cannabis and schizophrenia has been researched more intensively. The controversy regarding the reliability, clinical utility, and the existence of a cannabis withdrawal syndrome has also been settled. Recent studies also buttressed the possibility of acute and chronic effect of cannabis on various cognitive functions. There has been a plethora of research regarding the treatment for cannabis use disorders. But the new and most interesting area of research is concentrated on the endocannabinoid system and its contribution in various psychiatric disorders.

Open-label pilot study of quetiapine treatment for cannabis dependence

BACKGROUND

There are no efficacious pharmacotherapies for cannabis dependence. The effects of quetiapine are well matched to the symptoms of cannabis withdrawal and could be useful in the treatment of cannabis dependence.

OBJECTIVES

To evaluate quetiapine for the treatment of cannabis dependence and determine the optimal dosing.

METHODS

In an eight-week open-label outpatient pilot trial, we evaluated the feasibility of quetiapine treatment for cannabis dependence in 15 outpatients. Quetiapine was gradually titrated to 600 mg or the maximum tolerated dose.

RESULTS

The mean study retention was 6.5 weeks (±2.3), with 67% of participants completing all eight weeks of the trial. The mean maximum dose achieved was 197 mg/day (range: 25-600 mg/day). Only two of the 15 participants were able to achieve the target dose of 600 mg daily. There were no serious adverse events and no participants were discontinued from the trial due to adverse effects. The most common reported adverse effects were fatigue (80% of participants) and somnolence (47%). From baseline to week 8, the modeled overall decrease in daily dollar value of marijuana was 76.3% (CI: 63.4%, 84.7%). Over the eight weeks of the study, there was a 46.9% (CI: 11%, 68.3%) decrease in urine tetrahydrocannabinol-9-carboxylic acid (THCOOH) levels.

CONCLUSIONS

These preliminary results are promising in that quetiapine treatment was tolerated by cannabis-dependent patients and associated with decreased cannabis use. The recommended maximum target dose for cannabis-dependent patients is 300 mg daily. These preliminary data support further evaluation of quetiapine as a treatment for cannabis dependence.

Dopamine D3 receptors as a therapeutic target for methamphetamine dependence

BACKGROUND

Methamphetamine (MA) use disorders are major public health problems nationally and worldwide and treatment remains an unmet need.

OBJECTIVES

(1) To review preclinical and clinical studies identifying the dopamine D3 receptor as a therapeutic target for substance use disorders (SUDs), including MA dependence, (2) to consider buspirone (Buspar®) as a potential medication based on its dopamine D3 receptor antagonist properties, and (3) to evaluate the safety and initial efficacy of buspirone in a pilot study of MA-dependent individuals.

METHODS

Literature on the dopamine D3 receptor as a therapeutic target and on the potential of buspirone as a novel therapy for MA dependence was reviewed. The cardiovascular and subjective effects of intravenous MA challenge were assessed in five non-treatment seeking individuals. Participants met DSM-IV criteria for MA dependence and were treated subacutely (9 days) with buspirone (60 mg daily).

RESULTS

The literature identified the dopamine D3 receptor as a therapeutic target for MA dependence, a safe and approved medication, and a valuable opportunity to re-purpose buspirone for treating MA dependence and perhaps other SUDs. Pilot data (n = 5) indicated that buspirone is safe in MA-using individuals and comparison against historical placebo data from this laboratory suggested that at least some aspects of the subjective properties of MA may be diminished during buspirone treatment.

CONCLUSION

Future studies should include a small-scale, placebo-controlled Phase IIa trial of buspirone in MA dependence.

Treatment of cannabis dependence using escitalopram in combination with cognitive-behavior therapy: a double-blind placebo-controlled study

BACKGROUND

Cannabis is the most frequently used illegal substance in the United States and Europe. There is a dramatic increase in the demand for treatment for cannabis dependence. Cannabis users frequently have co-morbid mood symptoms, especially depression and anxiety, and regular cannabis users may self-medicate for such symptoms.

OBJECTIVES

We report a double-blind, placebo-controlled treatment study, for the prevention of cannabis use in cannabis-dependent individuals.

METHOD

Regular cannabis-dependent users (n = 52) were treated for 9 weeks with weekly cognitive-behavior and motivation-enhancement therapy sessions together with escitalopram 10 mg/day. Urine samples were collected to monitor delta-9 tetrahydrocannabinol (THC) during treatment and questionnaires were administered to assess anxiety and depression.

RESULTS

We observed a high rate of dropout (50%) during the 9-week treatment program. Fifty-two patients were included in the intention-to-treat analysis. Of these, ten (19%) remained abstinent after 9 weeks of treatment as indicated by negative urine samples for THC. Escitalopram provided no advantage over placebo in either abstinence rates from cannabis or anxiety and depression scores during the withdrawal and abstinent periods.

CONCLUSIONS

Escitalopram treatment does not provide an additional benefit either for achieving abstinence, or for the treatment of the cannabis withdrawal syndrome. Due to limitations of our study, namely, a high dropout rate and effects of low abstinence rates on measures of anxiety, depression and withdrawal, it is premature to conclude that selective serotonin reuptake inhibitors are not effective for treatment of the cannabis withdrawal syndrome.

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

RATIONALE

Preclinical studies suggest that lithium carbonate (lithium) can reduce precipitated cannabinoid withdrawal in rats by stimulating release of the neuropeptide oxytocin, while two open-label studies indicate lithium may ameliorate cannabis withdrawal symptoms in humans.

OBJECTIVES

This study was conducted to examine the efficacy and safety of lithium in the inpatient management of cannabis withdrawal and to determine whether lithium affects plasma oxytocin and the rate of elimination of plasma cannabinoids during abstinence.

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 given twice a day under double-blind randomized controlled trial (RCT) conditions. Primary outcomes included withdrawal severity [cannabis withdrawal scale (CWS)], rates of detoxification completion, and adverse events. Plasma cannabinoids, plasma oxytocin and serum lithium levels were measured repeatedly over admission. Follow-up research interviews were conducted at 14, 30, and 90 days postdischarge.

RESULTS

Lithium did not significantly affect total CWS scores relative to placebo, although it significantly reduced individual symptoms of "loss of appetite," "stomach aches," and "nightmares/strange dreams." No significant group differences were found in treatment retention or adverse events. Lithium did not increase plasma oxytocin levels nor influence the rate of elimination of cannabinoids. Both placebo- and lithium-treated participants showed reduced levels of cannabis use (verified by urinalysis) and improved health and psychosocial outcomes at 30- and 90-day follow-up relative to pretreatment baselines.

CONCLUSIONS

Despite the strong rationale for the present study, the efficacy of lithium over placebo in the management of cannabis withdrawal was not demonstrated.

Youth marijuana use: state of the science for the practicing clinician

PURPOSE OF REVIEW

Despite widespread marijuana use among adolescents, accurate information on known health effects is poorly disseminated to clinicians and their patients. Amidst rapidly evolving drug policy in the United States and elsewhere, it is imperative that providers understand the short-term and long-term consequences of marijuana use.

RECENT FINDINGS

Research on regular marijuana use highlights a unique susceptibility of the developing adolescent brain to adverse neurocognitive and psychiatric outcomes. Although studies have not firmly established causality, onset of regular marijuana use in adolescence is associated with later decline in cognitive function, as well as with adult onset of psychosis and anxiety. Educational and employment outcomes may be poorer among regular marijuana-using adolescents. A number of other adverse respiratory, cardiovascular, endocrine and gastrointestinal associations with regular marijuana use have also been established. Good screening tools and promising brief intervention and behavioral treatment programs are available to clinicians, who are in a position to identify problematic marijuana use among adolescents.

SUMMARY

A common misperception among youth is that marijuana use is without harm. However, adolescent marijuana use may have measurable, durable, and potentially irreversible effects on later cognitive function and mental health.

Novel Pharmacologic Approaches to Treating Cannabis Use Disorder

With large and increasing numbers of people using cannabis, the development of cannabis use disorder (CUD) is a growing public health concern. Despite the success of evidence-based psychosocial therapies, low rates of initial abstinence and high rates of relapse during and following treatment for CUD suggest a need for adjunct pharmacotherapies. Here we review the literature on medication development for the treatment of CUD, with a particular focus on studies published within the last three years (2010-2013). Studies in both the human laboratory and in the clinic have tested medications with a wide variety of mechanisms. In the laboratory, the following medication strategies have been shown to decrease cannabis withdrawal and self-administration following a period of abstinence (a model of relapse): the cannabinoid receptor agonist, nabilone, and the adrenergic agonist, lofexidine, alone and in combination with dronabinol (synthetic THC), supporting clinical testing of these medication strategies. Antidepressant, anxiolytic and antipsychotic drugs targeting monoamines (norepinephrine, dopamine, and serotonin) have generally failed to decrease withdrawal symptoms or laboratory measures of relapse. In terms of clinical trials, dronabinol and multiple antidepressants (fluoxetine, venlafaxine and buspirone) have failed to decrease cannabis use. Preliminary results from controlled clinical trials with gabapentin and N-acetylcysteine (NAC) support further research on these medication strategies. Data from open label and laboratory studies suggest lithium and oxytocin also warrant further testing. Overall, it is likely that different medications will be needed to target distinct aspects of problematic cannabis use: craving, ongoing use, withdrawal and relapse. Continued research is needed in preclinical, laboratory and clinical settings.

New Developments in Understanding and Treating Adolescent Marijuana Dependence

BACKGROUND

Marijuana is the most commonly used illicit substance in the United States and worldwide. Marijuana use is a problem of increasing magnitude among adolescents. Use typically begins in adolescence and is associated with a variety of adverse outcomes.

METHOD

This article will present an overview of trends in marijuana use, and will review the endocannabinoid system and marijuana. It will discuss recent policy developments in US and their implications, especially for adolescents. Existing treatments will be reviewed, including findings from a recent randomized double-blind trial of N-acetylcysteine, a compound that reverses the dysregulation of the glutamate system that occurs in substance dependence.

CONCLUSIONS

The core treatment approaches include psychosocial interventions, sometimes in combination with each other. While a reduction in days of use is often achieved with most of these approaches, abstinence is a much more elusive goal. The evidence base for effective treatments remains inadequate especially with regard to adolescents, and there is an urgent need for more research in this area. Promising new treatments include N-acetylcysteine in conjunction with contingency management.

The effectiveness of treatments for cocaine dependence in schizophrenic patients: a systematic review

Objectives:

To evaluate and compare the effectiveness of available treatments for cocaine dependence in schizophrenic patients.

Method:

We searched articles published between May 2002 and June 2012 in the following databases: Scopus, Pubmed and Web of Knowledge. The key words utilised were “schizophrenia”, "dementia praecox", "schizophrenic disorder", "cocaine related disorder", "cocaine abuse", "cocaine addiction", "cocaine dependence", “treatment”, “therapeutic”, and "drug therapy”.

Selection of studies and data extraction:

Original articles in English, Portuguese and Spanish were selected. Controlled, double-blind and open-label studies involving only human subjects were included in this review.

Data Synthesis:

We found studies on typical and atypical antipsychotics and one monoamine transporter antagonist. There were few indications of the effectiveness of atypical antipsychotic medications for the treatment of cocaine dependence in patients with schizophrenia.

Conclusions:

We suggest that further studies be conducted with atypical antipsychotic medicationsand greater methodological strictness, including using a placebo group in the studies, so that health professionals can determine the real effectiveness of this class of medication for the treatment of cocaine dependence in schizophrenic patients.

Pharmacotherapies for cannabis dependence

BACKGROUND

Cannabis is the most prevalent illicit drug in the world. Demand for treatment of cannabis use disorders is increasing. There are currently no pharmacotherapies approved for treatment of cannabis use disorders.

OBJECTIVES

To assess the effectiveness and safety of pharmacotherapies as compared with each other, placebo or supportive care for reducing symptoms of cannabis withdrawal and promoting cessation or reduction of cannabis use.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (to 4 March 2014), MEDLINE (to week 3 February 2014), EMBASE (to 3 March 2014) and PsycINFO (to week 4 February 2014). We also searched reference lists of articles, electronic sources of ongoing trials and conference proceedings, and contacted selected researchers active in the area.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving the use of medications to reduce the symptoms and signs of 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 participants diagnosed as cannabis dependent or who were likely to be dependent.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. Two review authors assessed studies for inclusion and extracted data. All review authors confirmed the inclusion decisions and the overall process.

MAIN RESULTS

We included 14 randomised controlled trials involving 958 participants. For 10 studies the average age was 33 years; two studies targeted young people; and age data were not available for two studies. Approximately 80% of study participants were male. The studies were at low risk of selection, performance, detection and selective outcome reporting bias. Three studies were at risk of attrition bias.All studies involved comparison of active medication and placebo. The medications included preparations containing tetrahydrocannabinol (THC) (two studies), selective serotonin reuptake inhibitor (SSRI) antidepressants (two studies), mixed action antidepressants (three studies), anticonvulsants and mood stabilisers (three studies), an atypical antidepressant (two studies), an anxiolytic (one study), a norepinephrine reuptake inhibitor (one study) and a glutamatergic modulator (one study). One study examined more than one medication. Diversity in the medications and the outcomes reported limited the extent that analysis was possible. Insufficient data were available to assess the utility of most of the medications to promote cannabis abstinence at the end of treatment.There was moderate quality evidence that completion of treatment was more likely with preparations containing THC compared to placebo (RR 1.29, 95% CI 1.08 to 1.55; 2 studies, 207 participants, P = 0.006). There was some evidence that treatment with preparations containing THC was associated with reduced cannabis withdrawal symptoms and craving, but this latter outcome could not be quantified. For mixed action antidepressants compared with placebo (2 studies, 179 participants) there was very low quality evidence on the likelihood of abstinence from cannabis at the end of follow-up (RR 0.82, 95% CI 0.12 to 5.41), and moderate quality evidence on the likelihood of treatment completion (RR 0.93, 95% CI 0.71 to 1.21). For this same outcome there was very low quality evidence for the effects of SSRI antidepressants (RR 0.82, 95% CI 0.44 to 1.53; 2 studies, 122 participants), anticonvulsants and mood stabilisers (RR 0.78, 95% CI 0.42 to 1.46; 2 studies, 75 participants), and the atypical antidepressant, bupropion (RR 1.06, 95% CI 0.67 to 1.67; 2 studies, 92 participants). Available evidence on gabapentin (anticonvulsant) and N-acetylcysteine (glutamatergic modulator) was insufficient for quantitative estimates of their effectiveness, but these medications may be worth further investigation.

AUTHORS' CONCLUSIONS

There is incomplete evidence for all of the pharmacotherapies investigated, and for many of the outcomes the quality was downgraded due to small sample sizes, inconsistency and risk of attrition bias. The quantitative analyses that were possible, combined with general findings of the studies reviewed, indicate that SSRI antidepressants, mixed action antidepressants, atypical antidepressants (bupropion), anxiolytics (buspirone) and norepinephrine reuptake inhibitors (atomoxetine) are probably of little value in the treatment of cannabis dependence. Preparations containing THC are of potential value but, given the limited evidence, this application of THC preparations should be considered still experimental. Further studies should compare different preparations of THC, dose and duration of treatment, adjunct medications and therapies. The evidence base for the anticonvulsant gabapentin and the glutamatergic modulator N-acetylcysteine is weak, but these medications are also worth further investigation.

Dopamine D3 receptor ligands for drug addiction treatment: update on recent findings

The dopamine D3 receptor is located in the limbic area and apparently mediates selective effects on motivation to take drugs and drug-seeking behaviors, so that there has been considerable interest on the possible use of D3 receptor ligands to treat drug addiction. However, only recently selective tools allowing studying this receptor have been developed. This chapter presents an overview of findings that were presented at a symposium on the conference Dopamine 2013 in Sardinia in May 2013. Novel neurobiological findings indicate that drugs of abuse can lead to significant structural plasticity in rodent brain and that this is dependent on the availability of functional dopamine D3 autoreceptor, whose activation increased phosphorylation in the ERK pathway and in the Akt/mTORC1 pathway indicating the parallel engagement of a series of intracellular signaling pathways all involved in cell growth and survival. Preclinical findings using animal models of drug-seeking behaviors confirm that D3 antagonists have a promising profile to treat drug addiction across drugs of abuse type. Imaging the D3 is now feasible in human subjects. Notably, the development of (+)-4-propyl-9-hydroxynaphthoxazine ligand used in positron emission tomography (PET) studies in humans allows to measure D3 and D2 receptors based on the area of the brain under study. This PET ligand has been used to confirm up-regulation of D3 sites in psychostimulant users and to reveal that tobacco smoking produces elevation of dopamine at the level of D3 sites. There are now novel antagonists being developed, but also old drugs such as buspirone, that are available to test the D3 hypothesis in humans. The first results of clinical investigations are now being provided. Overall, those recent findings support further exploration of D3 ligands to treat drug addiction.

Cognitive behavioral therapy and the nicotine transdermal patch for dual nicotine and cannabis dependence: a pilot study

BACKGROUND AND OBJECTIVES

We assessed the feasibility of a new cognitive behavioral therapy (CBT) manual, plus transdermal patch nicotine replacement therapy (NRT), to treat co-occurring nicotine and cannabis dependence.

METHOD

Seven of 12 (58.3%) adults with DSM-IV diagnoses of both nicotine and cannabis dependence completed 10 weeks of individual CBT and NRT.

RESULTS

Participants smoked 12.6 ± 4.9 tobacco cigarettes per day at baseline, which was reduced to 2.1 ± 4.2 at the end of treatment (F[5]  = 23.5, p < .0001). The reduction in cannabis use from 10.0 ± 5.3 inhalations per day at baseline to 8.0 ± 5.3 inhalations per day at 10 weeks was not significant (F[5]  = 1.12, p = .37). There was a significant decrease from the mean baseline Fagerstrom Test for Nicotine Dependence scores at weeks 4, 6, 8, and 10 of treatment (F[4]  = 19.8, p < .001) and mean Client Satisfaction Questionnaire scores were uniformly high (30.6 ± 1.9).

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

A CBT plus NRT treatment program significantly reduced tobacco smoking but did not significantly reduce cannabis use in individuals with co-occurring nicotine and cannabis dependence. There was no compensatory increase in cannabis use following the reduction in tobacco smoking, suggesting that clinicians can safely pursue simultaneous treatment of co-occurring nicotine and cannabis dependence. The intervention was well-liked by the 7 of the 12 enrollees who completed the study.

A randomized double-blind, placebo-controlled trial of venlafaxine-extended release for co-occurring cannabis dependence and depressive disorders

AIM

To evaluate whether venlafaxine-extended release (VEN-XR) is an effective treatment for cannabis dependence with concurrent depressive disorders.

DESIGN

This was a randomized, 12-week, double-blind, placebo-controlled trial of out-patients (n = 103) with DSM-IV cannabis dependence and major depressive disorder or dysthymia. Participants received up to 375 mg VEN-XR on a fixed-flexible schedule or placebo. All patients received weekly individual cognitive-behavioral psychotherapy that primarily targeted marijuana use.

SETTINGS

The trial was conducted at two university research centers in the United States.

PARTICIPANTS

One hundred and three cannabis-dependent adults participated in the trial.

MEASUREMENTS

The primary outcome measures were (i) abstinence from marijuana defined as at least two consecutive urine-confirmed abstinent weeks and (ii) improvement in depressive symptoms based on the Hamilton Depression Rating Scale.

FINDINGS

The proportion of patients achieving a clinically significant mood improvement (50% decrease in Hamilton Depression score from baseline) was high and did not differ between groups receiving VEN-XR (63%) and placebo (69%) (χ1 (2)  = 0.48, P = 0.49). The proportion of patients achieving abstinence was low overall, but was significantly worse on VEN-XR (11.8%) compared to placebo (36.5%) (χ1 (2)  = 7.46, P < 0.01; odds ratio = 4.51, 95% confidence interval: 1.53, 13.3). Mood improvement was associated with reduction in marijuana use in the placebo group (F1,179  = 30.49, P < 0.01), but not the VEN-XR group (F1,186  = 0.02, P = 0.89).

CONCLUSIONS

For depressed, cannabis-dependent patients, venlafaxine-extended release does not appear to be effective at reducing depression and may lead to an increase in cannabis use.

Effects of chronic buspirone treatment on cocaine self-administration

Cocaine abuse and dependence is a major public health problem that continues to challenge medication-based treatment. Buspirone (Buspar) is a clinically available, non-benzodiazepine anxiolytic medication that acts on both serotonin and dopamine systems. In recent preclinical studies, acute buspirone treatment reduced cocaine self-administration at doses that did not also decrease food-reinforced behavior in rhesus monkeys (Bergman et al, 2012). The present study evaluated the effectiveness of chronic buspirone treatment on self-administration of cocaine and food. Five adult rhesus monkeys (Macaca mulatta) were trained to self-administer cocaine and food during four 1-h daily sessions under a second-order schedule of reinforcement (FR2 [VR 16:S]). Buspirone (0.32 and 0.56 mg/kg/h) was administered intravenously through one lumen of a double-lumen catheter every 20 min for 23 h each day for 7-10 consecutive days. Each buspirone treatment period was followed by saline control treatment until drug- and food-maintained responding returned to baseline levels. Buspirone significantly reduced responding maintained by cocaine, and shifted the dose-effect curve downwards. Buspirone had minimal effects on food-maintained responding. In cocaine discrimination studies, buspirone (0.1-0.32 mg/kg, IM) did not antagonize the discriminative stimulus and rate-altering effects of cocaine in four of six monkeys. These findings indicate that buspirone selectively attenuates the reinforcing effects of cocaine in a nonhuman primate model of cocaine self-administration, and has variable effects on cocaine discrimination.

Evaluation of buspirone for relapse-prevention in adults with cocaine dependence: an efficacy trial conducted in the real world

Cocaine dependence is a significant public health problem for which there are currently no FDA-approved medications. Hence, identifying candidate compounds and employing an efficient evaluation process is crucial. This paper describes key design decisions made for a National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN) study that uses a novel two-stage process to evaluate buspirone (60 mg/day) for cocaine-relapse prevention. The study includes pilot (N=60) and full-scale (estimated N=264) trials. Both trials will be randomized, double-blind, and placebo-controlled and both will enroll treatment-seeking cocaine-dependent participants engaged in inpatient/residential treatment and scheduled for outpatient treatment post-discharge. All participants will receive contingency management in which incentives are given for medication adherence as evaluated by the Medication Events Monitoring System (MEMS). The primary outcome measure is maximum days of continuous cocaine abstinence, as assessed by twice-weekly urine drug screens (UDS) and self-report, during the 15-week outpatient treatment phase. Drug-abuse outcomes include cocaine use as assessed by UDS and self-report of cocaine use, other substance use as assessed by UDS and self-report of substance use (i.e., alcohol and/or illicit drugs), cocaine bingeing, HIV risk behavior, quality of life, functioning, and substance abuse treatment attendance. Unique aspects of the study include conducting an efficacy trial in community treatment programs, a two-stage process to efficiently evaluate buspirone, and an evaluation of mediators by which buspirone might exert a beneficial effect on relapse prevention.

BAP updated guidelines: evidence-based guidelines for the pharmacological management of substance abuse, harmful use, addiction and comorbidity: recommendations from BAP

The British Association for Psychopharmacology guidelines for the treatment of substance abuse, harmful use, addiction and comorbidity with psychiatric disorders primarily focus on their pharmacological management. They are based explicitly on the available evidence and presented as recommendations to aid clinical decision making for practitioners alongside a detailed review of the evidence. A consensus meeting, involving experts in the treatment of these disorders, reviewed key areas and considered the strength of the evidence and clinical implications. The guidelines were drawn up after feedback from participants. The guidelines primarily cover the pharmacological management of withdrawal, short- and long-term substitution, maintenance of abstinence and prevention of complications, where appropriate, for substance abuse or harmful use or addiction as well management in pregnancy, comorbidity with psychiatric disorders and in younger and older people.

A proof-of-concept randomized controlled study of gabapentin: effects on cannabis use, withdrawal and executive function deficits in cannabis-dependent adults

There are no FDA-approved pharmacotherapies for cannabis dependence. Cannabis is the most widely used illicit drug in the world, and patients seeking treatment for primary cannabis dependence represent 25% of all substance use admissions. We conducted a phase IIa proof-of-concept pilot study to examine the safety and efficacy of a calcium channel/GABA modulating drug, gabapentin, for the treatment of cannabis dependence. A 12-week, randomized, double-blind, placebo-controlled clinical trial was conducted in 50 unpaid treatment-seeking male and female outpatients, aged 18-65 years, diagnosed with current cannabis dependence. Subjects received either gabapentin (1200 mg/day) or matched placebo. Manual-guided, abstinence-oriented individual counseling was provided weekly to all participants. Cannabis use was measured by weekly urine toxicology and by self-report using the Timeline Followback Interview. Cannabis withdrawal symptoms were assessed using the Marijuana Withdrawal Checklist. Executive function was measured using subtests from the Delis-Kaplan Executive Function System. Relative to placebo, gabapentin significantly reduced cannabis use as measured both by urine toxicology (p=0.001) and by the Timeline Followback Interview (p=0.004), and significantly decreased withdrawal symptoms as measured by the Marijuana Withdrawal Checklist (p<0.001). Gabapentin was also associated with significantly greater improvement in overall performance on tests of executive function (p=0.029). This POC pilot study provides preliminary support for the safety and efficacy of gabapentin for treatment of cannabis dependence that merits further study, and provides an alternative conceptual framework for treatment of addiction aimed at restoring homeostasis in brain stress systems that are dysregulated in drug dependence and withdrawal.

State of the art treatments for cannabis dependence

The treatment of cannabis dependence can be viewed as a cup half empty or half full. On the one hand, few people who might benefit from treatment actually receive it. Among those who undergo treatment in randomized trials, long-term abstinence is achieved by fewer than 20%. Moderate use goals have been associated with decreases in consequences, but the differential impact of such goals on the long-term course of cannabis dependence is unknown. Optimal duration of treatment is unclear, and certain populations, particularly patients with co-occurring disorders, have not been studied adequately. Twelve-step programs are low cost, effective for other substance use disorders, and readily available in most regions of the world. However, their role and efficacy in cannabis dependence has not been examined. Finally, effective pharmacologic treatments are under development, but none have yet been firmly established. On the other hand, psychotherapeutic strategies used to treat other substance use disorders can be effective for cannabis dependence. A recent meta-analysis of psychosocial interventions for illicit substance use disorders found that treatments for cannabis dependence had comparatively larger effect sizes than treatments for other substance use disorders. Combination therapies have proven most effective, particularly those that begin with a motivational intervention, utilize incentives to enhance the commitment to change, and teach behavioral and cognitive copings skills to prevent relapse. Among adolescents, family engagement and collaboration with community stakeholders adds substantial value. Although only 9% of cannabis users develop cannabis dependence, the volume of people who smoke cannabis ensures that the total number of people in need of help is larger than the capacity of substance abuse specialty services. Thus, although efforts to refine and improve the efficacy of treatment interventions continue, innovations that increase the availability and accessibility of treatment are also needed. Computer- and phone-based interventions, social media, and brief interventions that can be implemented in primary care settings are areas that may hold promise for reaching at-risk populations. Adolescents and persons with co-occurring mental illness are at particularly high risk of cannabis dependence, and may suffer disproportionately from cannabis’s adverse effects. As in the treatment of other substance use disorders, there is a need for a continuing care model with long-term follow-up that extends past the periods typically evaluated in treatment studies. Additionally, there is a need for further investigation of genetic underpinnings and endophenotypes underlying cannabis dependence to identify neurobiological mechanisms for targeted intervention. One benefit of the societal focus on cannabis has been a prominent increase in research covering everything from the basic science to public health impact of cannabis. Over the next decade, physicians who provide treatment for individuals with cannabis dependence are likely to see their armamentarium of effective interventions expand, to the ultimate betterment of patients, their families, and society at large.

Validity of Timeline Follow-Back for self-reported use of cannabis and other illicit substances--systematic review and meta-analysis

BACKGROUND

Timeline Follow-Back (TLFB) is a widely used, calendar-based measure of self-reported use of (among other things) illicit substances. We examined agreement between TLFB and biological measures for illicit substances.

METHODS

PubMed, PsycINFO, Cochrane CENTRAL, and EMBASE were searched in December 2010. 16,633 papers screened to identify those that measured illicit substance use by both TLFB and biological measures. We extracted data on agreement between TLFB and biological measures, sample size, study type, inclusion criteria of participants, and length of recall of TLFB.

RESULTS

Twenty-nine papers were included, almost exclusively in substance-use-disorder populations. Some studies reported several overall agreement rates, e.g. over time. Lowest and highest weighted average agreement rates were: for cannabis, 87.3% (95% confidence interval 86.9% to 87.7%) and 90.9% (90.5% to 91.4%); for cocaine, 79.3% (79.1% to 79.6%) and 84.1% (83.9% to 84.2%); for opiates 94.0% (93.5% to 94.5%) for both weighted averages; and for studies not distinguishing between substances, 88.5% (88.4 to 88.7%) and 91.0% (90.7% to 91.2%). Higher agreement was found in populations without psychiatric comorbidity, and lower agreement in randomized controlled trials. Publication bias or selective outcome reporting bias was not detected.

CONCLUSIONS

TLFB validly detects use of illicit substances in populations with substance use disorders. Using TLFB may limit the need for biological samples, making information on illicit substance use easier and less costly to obtain and analyze.

Primary outcomes in two randomized controlled trials of treatments for cannabis use disorders

BACKGROUND

While several randomized controlled trials evaluating a range of treatments for cannabis use disorders have appeared in recent years, these have been marked by inconsistency in selection of primary outcomes, making it difficult to compare outcomes across studies.

METHOD

With the aim of identifying meaningful and reliable outcome domains in treatment studies of cannabis use disorders, we evaluated multiple indicators of marijuana use, marijuana problems, and psychosocial functioning from two independent randomized controlled trials of behavioral treatments for cannabis use disorders (Ns=450 and 136).

RESULTS

Confirmatory factor analysis indicated that the best-fitting model of outcomes in both trials encompassed three distinct factors: frequency of marijuana use, severity of marijuana use, and psychosocial functioning. In both trials, frequency of marijuana use and longest period of abstinence during treatment were most strongly associated with outcome during follow-up. Using two categorical definitions of "clinically significant improvement," individuals who demonstrated improvement differed on most end-of-treatment and long-term outcomes from those who did not improve.

CONCLUSIONS

Results may guide future randomized controlled trials of treatments for cannabis use disorders in the collection of relevant end-of-treatment outcomes and encourage consistency in the reporting of outcomes across trials.