Psychosocial and pharmacological interventions for the treatment of cannabis use disorder

Association of Cannabis Use Reduction With Improved Functional Outcomes: An Exploratory Aggregated Analysis From Seven Cannabis Use Disorder Treatment Trials to Extract Data-Driven Cannabis Reduction Metrics

OBJECTIVE

This exploratory analysis sought to determine whether decreases in cannabis use are associated with improvements in cannabis-related problems and functional outcomes, and if so, what percentage decrease is associated with improvement.

METHODS

Data were aggregated from seven cannabis use disorder treatment trials conducted in the United States (N=920; ages 13 years and older; mean age, 25 years; 30% female, 7% Black, 11% Hispanic/Latinx). Outcome measures included the patient-reported Marijuana Problems Scale (MPS), Health-Related Quality of Life scale (HRQOL), and Pittsburgh Sleep Quality Index and the clinician-rated Clinical Global Impressions (CGI) severity and improvement scales (CGI-S and CGI-I). Generalized estimating equations tested the association between changes in 4-week cannabis use and improvements in functional outcomes. Classification and regression tree (CART) models were developed to determine what reductions in cannabis use could be used as classifiers of improvement.

RESULTS

Decreases in the amount and frequency of cannabis use were significantly associated with improvements in MPS severity and total scores as well as improvements on the CGI-I and in sleep quality, but not improvements on the HRQOL. CART models performed best for CGI-I scores (72%-75% correct classification), while other outcome measures did not perform as well (40%-62% correct classification). CART models showed improvements on the CGI at 74% reduction in use amounts and 47% reduction in use days.

CONCLUSIONS

Reductions in cannabis use (∼50% reduction in use days and ∼75% reduction in use amounts) were associated with clinician-assessed improvement, which suggests that cannabis use reduction may yield benefit among individuals with cannabis use disorder. These exploratory results extract a data-driven metric to inform future studies, clinicians, patients, and policy recommendations.

Cannabis Use Disorder Associated With Increased Risk of Postoperative Complications After Hip or Knee Arthroplasties: A Meta-analysis of Observational Studies

INTRODUCTION

With the legalization of marijuana in the United States, the number of patients with cannabis use disorder (CUD) in the joint arthroplasty population has increased markedly. The primary purpose of this meta-analysis was to determine whether there were differences in clinical and economic outcomes after total joint arthroplasty (TJA) between patients with and without perioperative CUD.

METHODS

We searched PubMed, Embase, Scopus, and Web of Science databases up to July 2018 to identify all eligible studies investigating the association of CUD with postoperative outcomes in patients undergoing TJA. Postoperative outcomes assessed consisted of complications, readmission, length of stay (LOS), implant revision, and cost of care. For dichotomous outcomes, pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated using a random effects model.

RESULTS

We identified 10 retrospective cohort studies with a total of 17,981,628 study participants. Patients with CUD had significantly higher odds of medical complications (OR 1.33 [95% CI 1.07 to 1.66], P = 0.01) and implant-related complications (OR 1.75 [95% CI: 1.64 to 1.88], P < 0.00001) than noncannabis users. Specifically, CUD was associated with significantly increased odds of cardiac complications (OR 1.95 [95% CI 1.50 to 2.54], P < 0.00001), cerebrovascular accidents (OR 2.06 [95% CI 1.66 to 2.57], P < 0.00001), postoperative infections (OR 1.68 [95% CI 1.34 to 2.10], P < 0.00001), periprosthetic fracture (OR 1.42 [95% CI 1.19 to 1.70], P < 0.0001), mechanical loosening (OR 1.54 [95% CI 1.42 to 1.66], P < 0.00001), and dislocation/instability (OR 1.88 [95% CI 1.32 to 2.68], P = 0.0005). Longer LOS and higher cost of care were also found in patients with CUD.

CONCLUSION

This study strengthens the body of evidence that patients with CUD face higher risk of postoperative complications and greater financial burden after knee and hip arthroplasties. Physicians should inform patients about adverse outcomes and undertake appropriate risk adjustments before elective orthopaedic surgery.

LEVEL OF EVIDENCE

Level III.

Cannabis use disorder: from neurobiology to treatment

Cannabis has been legalized for medical and recreational purposes in multiple countries. A large number of people are using cannabis and some will develop cannabis use disorder (CUD). There is a growing recognition that CUD requires specific interventions. This Review will cover this topic from a variety of perspectives, with a particular emphasis on neurobiological findings and innovative treatment approaches that are being pursued. We will first describe the epidemiology and burden of disease of CUD, including risk factors associated with CUD (both in terms of general risk and genetic risk variants). Neurobiological alterations identified in brain imaging studies will be presented. Several psychosocial interventions that are useful for the management of CUD, including motivational enhancement therapy, behavioral and cognitive therapy, and contingency management, will be covered. Although no pharmacological interventions are yet approved for CUD, we present the most promising pharmacological interventions being tested.

Effectiveness of cannabis use and cannabis use disorder interventions: a European and international data synthesis

This data synthesis examined the effectiveness of behavioural and pharmacological approaches for cannabis treatment. We integrated findings from high level evidence studies and prioritised data from Europe when available. The synthesis found that only a relatively small number of published behavioural and pharmacological studies on cannabis interventions have been conducted in Europe. Applying both European and non-European data, it was found that Cognitive Behavioural Therapy (CBT) and/or Motivational Enhancement Therapy (MET) improved short-term outcomes in the frequency of cannabis use and dependency severity, although abstinence outcomes were less consistent. These improvements were typically not maintained nine months after treatment. CBT and MET (or combined CBT + MET) treatments that extend beyond four sessions were more effective than fewer sessions over a shorter duration. Combining CBT or MET (or combined CBT + MET) with adjunctive Contingency Management (CM) improved therapeutic outcomes. No pharmacotherapies have been approved for the management of cannabis use, cannabis use disorders or cannabis withdrawal. Despite only weak evidence to support the use of pharmacological agents, some are used 'off-label' to manage withdrawal symptoms outside clinical trials.

Brief Interventions for Cannabis Using Adolescents

This article discusses the application of brief interventions to address adolescents with a cannabis use problem. Topics include a general model of brief interventions, the outcome literature, existing brief interventions that focus on youth cannabis use, adjustments to a brief intervention when addressing cannabis, referral to treatment issues, personalizing a brief intervention, the need to address coexisting problems, and future directions.

Implementation and Preliminary Evaluation of a 12-Week Cognitive Behavioural and Motivational Enhancement Group Therapy for Cannabis Use Disorder

Background

The purpose of this paper is to provide a preliminary evaluation of treatment outcomes, retention and client satisfaction following a 12-week combined cognitive behavioural therapy (CBT) and motivational enhancement therapy (MET) group treatment for cannabis use disorder (CUD) delivered in an outpatient setting. Implementation of the program is also described.

Methods

A retrospective observational cohort study was conducted using data collected from medical records and self-report assessments. Participants were treatment-seeking cannabis users at the Centre for Addiction and Mental Health, Toronto. Cannabis use, cannabis-related problems, craving, withdrawal symptoms, self-efficacy for remaining abstinent, depression and anxiety were assessed pre- and post-treatment. Treatment retention was calculated by inspecting clinic attendance records, and client satisfaction was evaluated using an anonymous feedback survey. Potential predictors of treatment outcomes and retention were investigated in exploratory analyses.

Results

Cannabis use was lower and days of abstinence higher post-treatment (vs pre-treatment). Post-treatment improvements in cannabis-related problems, craving, withdrawal symptoms, self-efficacy and mood were also observed. Completion of group treatment (⩾75% of sessions attended) was 57% and moderate levels of treatment satisfaction were reported.

Conclusions

This study provides preliminary evidence that a 12-week combined CBT and MET treatment for cannabis use disorder delivered in a novel group setting improves cannabis use outcomes. Potential predictors of reduced cannabis use and retention were identified. Future controlled studies are warranted, and strategies for increasing retention should be explored.

Brief Interventions for Cannabis Using Adolescents

This article discusses the application of brief interventions to address adolescents with a cannabis use problem. Topics include a general model of brief interventions, the outcome literature, existing brief interventions that focus on youth cannabis use, adjustments to a brief intervention when addressing cannabis, referral to treatment issues, personalizing a brief intervention, the need to address coexisting problems, and future directions.

Identifying risk-thresholds for the association between frequency of cannabis use and development of cannabis use disorder: A systematic review and meta-analysis

BACKGROUND

Cannabis use disorder (CUD) affects one-in-five cannabis users, presenting a major contributor to cannabis-associated disease burden. Epidemiological data identify the frequency of cannabis use as a risk factor for CUD. This review aimed to determine quantifiable risk-thresholds of the frequency of cannabis use for developing CUD.

METHODS

Systematic search of Medline, EMBASE, PsycInfo, CINAHL, and Web of Science for cohort/case-control studies that assessed the association between frequency of cannabis use and CUD from 2000 to 2022. Effect estimates were converted to risk ratios (RR). A random-effects multi-level multivariate meta-analytic approach was utilized, and sensitivity analyses conducted. Quality of included studies was assessed with the Newcastle Ottawa Scale.

RESULTS

Six prospective cohort studies were included in this review, drawn from two main source studies. Random-effect modeling showed a significant log-linear dose-response association between the frequency of cannabis use and CUD risk (p < 0.0001). The risk of CUD increased from RR:2.03 (95% CI:1.85-2.22) for 'yearly' use, to RR:4.12 (95% CI:3.44-4.95) for 'monthly" use, RR:8.37 (95% CI:6.37-11.00) for 'weekly' use, and RR:16.99 (95% CI:11.80-24.46) for 'daily' use. Multi-level modeling showed an absolute risk increase (ARI) from 3.5% (95% CI:2.6-4.7) for 'yearly' use, to 8.0% (95% CI:5.3-12.1) for 'monthly' use, to 16.8% (95% CI:8.8-32.0) for 'weekly' use, and 36% (95% CI:27.047.9) for 'daily' use.

CONCLUSION

A limited risk of CUD as a potential outcome of cannabis use exists even at infrequent levels of use, but significantly increases as frequency of use increases. Corresponding information should be conveyed to cannabis users as part of targeted prevention messaging to promote safer cannabis use.

The prevalence and pattern of cannabis use among patients attending a methadone treatment clinic in Nairobi, Kenya

BACKGROUND

Cannabis use during methadone treatment may negatively impact treatment outcomes. The aim of this study was to determine the prevalence and pattern of cannabis use among patients attending a methadone treatment clinic in Nairobi, Kenya.

METHODS

This was a retrospective study of 874 patients on methadone therapy at a methadone maintenance treatment clinic in Nairobi, Kenya from December 2014 to November 2018. Data on sociodemographic characteristics and drug use patterns based on urine drug screens was collected from patient files. Data was analyzed using Statistical Package for the Social Sciences (SPSS) for windows version 23.0.

RESULTS

Point prevalence of cannabis use was 85.8% (95% CI, 83.3 - 88.0) at baseline and 62.7% (95% CI, 59.5 - 65.8) during follow-up. A pattern of polysubstance use was observed where opioids, cannabis and benzodiazepines were the most commonly used drugs. The mean age of the patients was 35.3 (SD 9.0) years with the majority being male, unemployed (76%), (51.4%) had reached primary level of education, and (48.5%) were divorced or separated. University education was associated with reduced risk for cannabis use OR = 0.1 (95% CI, 0.02-0.8, p = 0.031).

CONCLUSION

Cannabis use is prevalent among patients attending a methadone treatment clinic in Kenya, suggesting need for targeted interventions to address the problem of cannabis use during methadone treatment.

The endocannabinoid system - current implications for drug development

In this review, the state of the art for compounds affecting the endocannabinoid (eCB) system is described with a focus on the treatment of pain. Amongst directly acting CB receptor ligands, clinical experience with ∆⁹ -tetrahydracannabinol and medical cannabis in chronic non-cancer pain indicates that there are differences between the benefits perceived by patients and the at best modest effect seen in meta-analyses of randomized controlled trials. The reason for this difference is not known but may involve differences in the type of patients that are recruited, the study conditions that are chosen and the degree to which biases such as reporting bias are operative. Other directly acting CB receptor ligands such as biased agonists and allosteric receptor modulators have not yet reached the clinic. Amongst indirectly acting compounds targeting the enzymes responsible for the synthesis and catabolism of the eCBs anandamide and 2-arachidonoylglycerol, fatty acid amide hydrolase (FAAH) inhibitors have been investigated clinically but were per se not useful for the treatment of pain, although they may be useful for the treatment of post-traumatic stress disorder and cannabis use disorder. Dual-acting compounds targeting this enzyme and other targets such as cyclooxygenase-2 or transient potential vanilloid receptor 1 may be a way forward for the treatment of pain.

A systematic review of technology-based psychotherapeutic interventions for decreasing cannabis use in patients with psychosis

Persistent use of cannabis in persons with psychosis is associated with poor symptomatic and functional outcomes and increased healthcare costs. Face-to-face psychological interventions (e.g., Cognitive Behavioral Therapy- [CBT], Motivation Enhancement Therapy- [MET]) are widely used in treating problematic cannabis use. We aimed to comprehensively review the efficacy of technology-based psychological interventions (TBPIs) in decreasing cannabis use, the design of TBPIs, and TBPI-related preferences in individuals with psychosis. For the systematic review, we searched six major databases from their inception to November 27, 2019. We included empirical articles of quantitative and qualitative methodologies related to TBPIs in individuals with psychosis and cannabis misuse and used narrative synthesis to report results. Only eight articles were found showing that technology-based motivational and psycho-education interventions and cognitive enhancement therapy were minimally efficient in achieving cannabis abstinence or decreasing frequency of use. Qualitative exploratory methods and participatory action research were used to elicit patient and clinician preferences and TBPIs were tailored accordingly to improve cannabis use related outcomes. Research on TBPIs in individuals with psychosis and cannabis misuse is in its early phases. A significant research effort is needed for the development of adapted interventions for CUD to capitalize on the potential of web-based applications.

Cannabinoid Hyperemesis Syndrome: A Review of Potential Mechanisms

Introduction: Cannabinoids have long been known for their ability to treat nausea and vomiting. Recent reports, however, have highlighted the paradoxical proemetic effects of cannabinoids. Cannabinoid hyperemesis syndrome (CHS) is characterized by cyclical episodes of nausea and vomiting, accompanied by abdominal pain following prolonged, high-dose cannabis use, which is alleviated by hot baths and showers. Little is known about the cause of this syndrome. Discussion: Cannabinoids produce a biphasic effect on nausea and vomiting, with low doses having an antiemetic effect and high doses producing emesis. Presentation and treatment of CHS are similar to cyclical vomiting syndrome as well as chemotherapy-related anticipatory nausea and vomiting, suggesting that these phenomena may share mechanisms. The prevalence of CHS is not known because of the symptomatic overlap with other disorders and the lack of knowledge of the syndrome by the public and physicians. Treatment with typical antiemetic drugs is ineffective for CHS, but anxiolytic and sedative drugs, along with hot showers, seem to be consistently effective at reducing symptoms. The only known way to permanently end CHS, however, is abstinence from cannabinoids. Case studies and limited pre-clinical data on CHS indicate that prolonged high doses of the main psychotropic compound in cannabis, Δ9-tetrahydrocannabinol (THC), result in changes to the endocannabinoid system by acting on the cannabinoid 1 (CB1) receptor. These endocannabinoid system changes can dysregulate stress and anxiety responses, thermoregulation, the transient receptor potential vanilloid system, and several neurotransmitters systems, and are thus potential candidates for mediating the pathophysiology of CHS. Conclusions: Excessive cannabinoid administration disrupts the normal functioning of the endocannabinoid system, which may cause CHS. More clinical and pre-clinical research is needed to fully understand the underlying pathophysiology of this disorder and the negative consequences of prolonged high-dose cannabis use.

Attentional bias towards cannabis cues in cannabis users: A systematic review and meta-analysis

INTRODUCTION

Attentional bias, the automatic selective attentional orientation towards drug-related stimuli is well demonstrated in substance users. However, attentional bias studies of cannabis users specifically have thus far been inconclusive. Thus, the aim of this systematic review and meta-analysis was to synthesize the currently available literature regarding cannabis related attentional bias in cannabis users.

METHODS

Literature search and selection was carried out, following the PRISMA guidelines, with all included studies investigating the relationship between cannabis use and attentional bias towards cannabis cues.

RESULTS

Fourteen manuscripts, reporting on 1271 participants (cannabis users n = 1044; controls n = 217), were considered for the systematic-review and majority were included in a meta-analysis. Studies reviewed used three types of attentional bias tasks: pictorial stimuli, word stimuli, and non-cannabis stimuli tasks. Greater attentional bias towards cannabis pictures (d = 0.42, P < 0.0001) and words (d = 0.63, P = 0.03) as well as both types of stimuli overall (d = 0.53, P < 0.0001) was observed in cannabis users compared to controls, though there was evidence of significant heterogeneity for both word stimuli and overall meta-analysis. Bigger effect sizes were associated with shorter durations of exposure to cannabis stimuli suggesting mainly automatic orientating rather than controlled attention processing.

CONCLUSIONS

These findings suggest that cannabis users display greater attentional bias towards cannabis cues, likely an automatic process, than control groups. Future studies employing shorter exposure durations may validate attentional bias as a treatment target for the development of interventions in people with cannabis use disorder.

Review: Does Gabapentin Relieve Opioids, Cannabis and Methamphetamines Addictions?

The study reviews the suitability of using Gabapentin for treating opioid, cannabis and methamphetamine use disorders. This revision consists of 61 biographical references based on a PubMed database search (January of 1983-May of 2018). Gabapentin displayed respectively 50% and 66.7% of success for treating methamphetamine dependence and opioid withdrawal symptoms. Furthermore, a few research studies have reported Gabapentin´s efficacy for alleviating cannabis dependence (two studies), and cannabis withdrawal symptoms (one study). Similarly, a single study reported Gabapentin reduction of opioid consumption during the detoxification process. Based on the revision, we can conclude that: (a) Gabapentin is useful for treating opioid withdrawal symptoms, (b) additional studies are necessary for elucidating the effectiveness of Gabapentin for treating methamphetamine dependence, cannabis dependence and its withdrawal symptoms, and (c) more studies are necessary to confirm the efficacy of Gabapentin in reducing opioid consumption during detoxification.

The Neuroscience of Drug Reward and Addiction

Drug consumption is driven by a drug's pharmacological effects, which are experienced as rewarding, and is influenced by genetic, developmental, and psychosocial factors that mediate drug accessibility, norms, and social support systems or lack thereof. The reinforcing effects of drugs mostly depend on dopamine signaling in the nucleus accumbens, and chronic drug exposure triggers glutamatergic-mediated neuroadaptations in dopamine striato-thalamo-cortical (predominantly in prefrontal cortical regions including orbitofrontal cortex and anterior cingulate cortex) and limbic pathways (amygdala and hippocampus) that, in vulnerable individuals, can result in addiction. In parallel, changes in the extended amygdala result in negative emotional states that perpetuate drug taking as an attempt to temporarily alleviate them. Counterintuitively, in the addicted person, the actual drug consumption is associated with an attenuated dopamine increase in brain reward regions, which might contribute to drug-taking behavior to compensate for the difference between the magnitude of the expected reward triggered by the conditioning to drug cues and the actual experience of it. Combined, these effects result in an enhanced motivation to "seek the drug" (energized by dopamine increases triggered by drug cues) and an impaired prefrontal top-down self-regulation that favors compulsive drug-taking against the backdrop of negative emotionality and an enhanced interoceptive awareness of "drug hunger." Treatment interventions intended to reverse these neuroadaptations show promise as therapeutic approaches for addiction.