Treatment of Cannabis Use Disorder: Current Science and Future Outlook

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.

The Impact of Cannabis Use Disorder on Suicidal and Nonsuicidal Self-Injury in Iraq/Afghanistan-Era Veterans with and without Mental Health Disorders

The objective of this study was to assess the association between cannabis use disorder (CUD) and self-injury among veterans. As expected, after adjusting for sex, age, sexual orientation, combat exposure, traumatic life events, traumatic brain injury, posttraumatic stress disorder, depression, alcohol use disorder, and noncannabis drug use disorder, CUD was significantly associated with both suicidal (OR = 3.10, p = .045) and nonsuicidal (OR = 5.12, p = .009) self-injury. CUD was the only variable significantly associated with self-injury in all three models examined. These findings are consistent with prior research among civilians and suggest that CUD may also increase veterans' risk for self-injurious behavior.

Approach bias modification for cannabis use disorder: A proof-of-principle study

BACKGROUND

More effective treatments for cannabis use disorder (CUD) are needed. Evidence suggests that biases in cognitive processing of drug-related stimuli are central to the development and maintenance of addiction. The current study examined the feasibility and effect of a novel intervention - approach bias modification (ApBM) - on cannabis approach bias and cue-reactivity.

METHODS

A randomized, double-blind, sham-controlled proof-of-principle laboratory experiment investigated the effect of a four-session computerized ApBM training protocol on cannabis approach bias and cue-reactivity in non-treatment seeking adults age 18-65 with CUD (N = 33). ApBM procedures involved responding to cannabis or neutral stimuli using a computer joystick to model approach or avoidance behavior. Reactivity to tactile, olfactory, and auditory cue sets was assessed with physiological (blood pressure and heart rate) and subjective (cannabis craving) measures. Cannabis use was assessed via self-report.

RESULTS

Participants receiving ApBM showed blunted cannabis cue-induced craving at the end of training compared to those in the sham-ApBM condition (p = .05). A preliminary gender effect on cannabis use was also found; men receiving ApBM reported fewer cannabis use sessions per day at the end of training compared to women (p = .02), while there were no differences between men and women in the sham condition. ApBM did not attenuate cannabis approach bias following training.

CONCLUSION

Preliminary results indicate that ApBM may be efficacious in reducing cannabis cue-reactivity and improving cannabis use outcomes. While encouraging, the results should be interpreted with caution. Investigation of ApBM as an adjunct to psychosocial treatments for treatment-seeking adults with CUD is warranted.

Abstinence and reduced frequency of use are associated with improvements in quality of life among treatment-seekers with cannabis use disorder

BACKGROUND AND OBJECTIVE

Many patients with cannabis use disorder (CUD) do not achieve or do not have abstinence as a goal of treatment, rather they reduce their use. Assessing outcome measures as they relate to functioning and reductions in cannabis use is an important area of study. Quality of life (QoL) shows promise as one such measure. Past studies have demonstrated gender differences in QoL and CUD. We aim to assess (1) the relationship between cannabis use and QoL and (2) gender effects in an outpatient medication treatment study for CUD.

METHODS

Data from an 11-weeks, double-blind, placebo-controlled trial of lofexidine and dronabinol for CUD (n = 62) was analyzed. Pearson's correlations between baseline QoL as measured with the Quality of Life, Enjoyment, and Satisfaction Questionnaire-Short Form (QLES-Q-SF) and cannabis use assessed with modified timeline follow-back (TLFB) were examined. Multiple linear regression models of cannabis use on end of study QLES-Q-SF were analyzed, while adjusting for baseline QLES-Q-SF, study arm, and gender. Moderation effects with gender were also tested.

RESULTS

No significant association between baseline cannabis use and QoL was found. End of study abstinence (F_{1,47   =}  8.34, p = .006) and reduced proportion of using days (F_1,47  = 9.48, p = .004) were each significantly associated with end of study QoL. Reduction in grams (F_1,27  = 0.25, p = .62) was not associated with QoL at end of study. Gender was not a significant moderator.

DISCUSSION AND CONCLUSIONS

Abstinence and lower frequency of use are associated with higher QoL, regardless of gender.

SCIENTIFIC SIGNIFICANCE

This is the first time QoL has been demonstrated to change over the course of CUD medication treatment. QoL is an important outcome in CUD treatment.

TRIAL REGISTRATION

NCT01020019. (Am J Addict 2018;27:101-107).

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.

Cannabis as Secondary Drug Is Not Associated With a Greater Risk of Death in Patients With Opiate, Cocaine, or Alcohol Dependence

BACKGROUND

The health burden of cannabis use in patients with other substance dependencies is not fully understood.

OBJECTIVE

To assess the impact of cannabis use as secondary drug on mortality of patients with other major substance use disorders.

PARTICIPANTS

Patients with opiate, cocaine, or alcohol dependence admitted to detoxification from 2001 to 2010 at a teaching hospital in Badalona, Spain.

MAIN MEASUREMENTS

Sociodemographic characteristics, drug use, medical comorbidities, and urine drug screens were obtained at admission. Deaths were ascertained through clinical records and a death registry. Mortality rates and Cox regression models were used to analyze the association between urinary cannabis and mortality.

RESULTS

A total of 474 patients (20% women) were admitted with a median age of 38 years (interquartile range: 32-44 years). The main substances that motivated admissions were opiates (27%), cocaine (24%), and alcohol (49%). Positive urinary cannabis was detected in 168 patients (35%). Prevalence of cannabis use among patients with opiate, cocaine, or alcohol dependence was 46.5%, 42.9%, and 25.5%, respectively. At admission, 110 (23.7%) patients had human immunodeficiency virus infection and 217 (46.5%) had hepatitis C virus infection. Patients were studied for a median of 5.6 years (interquartile range: 2.6-7.7 years) (2454.7 person-years), and at the end of the study, 50 patients (10.5%) had died, yielding a mortality rate of 2.04 × 100 patient-years (95% confidence interval: 1.53-2.66). There was no association between cannabis detection and overall mortality in the adjusted regression models [hazard ratio (95% confidence interval): 1.12 (0.60-2.00), P = 0.73], but acquired immune deficiency syndrome-related deaths were more frequent in those positive for cannabis (26% vs 2%, P = 0.03).

CONCLUSION

Positive urinary cannabis did not confer an increased risk of death in patients with severe opiate, cocaine or alcohol dependence.

Estimating treatment coverage for people with substance use disorders: an analysis of data from the World Mental Health Surveys

Substance use is a major cause of disability globally. This has been recognized in the recent United Nations Sustainable Development Goals (SDGs), in which treatment coverage for substance use disorders is identified as one of the indicators. There have been no estimates of this treatment coverage cross-nationally, making it difficult to know what is the baseline for that SDG target. Here we report data from the World Health Organization (WHO)'s World Mental Health Surveys (WMHS), based on representative community household surveys in 26 countries. We assessed the 12-month prevalence of substance use disorders (alcohol or drug abuse/dependence); the proportion of people with these disorders who were aware that they needed treatment and who wished to receive care; the proportion of those seeking care who received it; and the proportion of such treatment that met minimal standards for treatment quality ("minimally adequate treatment"). Among the 70,880 participants, 2.6% met 12-month criteria for substance use disorders; the prevalence was higher in upper-middle income (3.3%) than in high-income (2.6%) and low/lower-middle income (2.0%) countries. Overall, 39.1% of those with 12-month substance use disorders recognized a treatment need; this recognition was more common in high-income (43.1%) than in upper-middle (35.6%) and low/lower-middle income (31.5%) countries. Among those who recognized treatment need, 61.3% made at least one visit to a service provider, and 29.5% of the latter received minimally adequate treatment exposure (35.3% in high, 20.3% in upper-middle, and 8.6% in low/lower-middle income countries). Overall, only 7.1% of those with past-year substance use disorders received minimally adequate treatment: 10.3% in high income, 4.3% in upper-middle income and 1.0% in low/lower-middle income countries. These data suggest that only a small minority of people with substance use disorders receive even minimally adequate treatment. At least three barriers are involved: awareness/perceived treatment need, accessing treatment once a need is recognized, and compliance (on the part of both provider and client) to obtain adequate treatment. Various factors are likely to be involved in each of these three barriers, all of which need to be addressed to improve treatment coverage of substance use disorders. These data provide a baseline for the global monitoring of progress of treatment coverage for these disorders as an indicator within the SDGs.

Analysis of natural product regulation of cannabinoid receptors in the treatment of human disease

The organized, tightly regulated signaling relays engaged by the cannabinoid receptors (CBs) and their ligands, G proteins and other effectors, together constitute the endocannabinoid system (ECS). This system governs many biological functions including cell proliferation, regulation of ion transport and neuronal messaging. This review will firstly examine the physiology of the ECS, briefly discussing some anomalies in the relay of the ECS signaling as these are consequently linked to maladies of global concern including neurological disorders, cardiovascular disease and cancer. While endogenous ligands are crucial for dispatching messages through the ECS, there are also commonalities in binding affinities with copious exogenous ligands, both natural and synthetic. Therefore, this review provides a comparative analysis of both types of exogenous ligands with emphasis on natural products given their putative safer efficacy and the role of Δ9-tetrahydrocannabinol (Δ9-THC) in uncovering the ECS. Efficacy is congruent to both types of compounds but noteworthy is the effect of a combination therapy to achieve efficacy without unideal side-effects. An example is Sativex that displayed promise in treating Huntington's disease (HD) in preclinical models allowing for its transition to current clinical investigation. Despite the in vitro and preclinical efficacy of Δ9-THC to treat neurodegenerative ailments, its psychotropic effects limit its clinical applicability to treating feeding disorders. We therefore propose further investigation of other compounds and their combinations such as the triterpene, α,β-amyrin that exhibited greater binding affinity to CB₁ than CB₂ and was more potent than Δ9-THC and the N-alkylamides that exhibited CB₂ selective affinity; the latter can be explored towards peripherally exclusive ECS modulation. The synthetic CB₁ antagonist, Rimonabant was pulled from commercial markets for the treatment of diabetes, however its analogue SR144528 maybe an ideal lead molecule towards this end and HU-210 and Org27569 are also promising synthetic small molecules.

Effect of oxytocin pretreatment on cannabis outcomes in a brief motivational intervention

Motivational enhancement therapy (MET) is efficacious in reducing cannabis use, yet benefits are generally short-lived. Oxytocin is a hypothalamic neuropeptide that promotes prosocial behaviors and plays a role in drug-related neuroadaptations; as such, oxytocin may enhance the effect of MET on cannabis outcomes. Cannabis dependent adults were randomized to receive MET plus oxytocin (n =8) or placebo (n =8). Participants receiving oxytocin showed reductions in amount of cannabis used daily and number of sessions per day. Participants receiving placebo did not evidence significant reductions. Powered clinical trials of oxytocin-enhanced MET for cannabis use disorder are warranted.

Gender differences among treatment-seeking adults with cannabis use disorder: Clinical profiles of women and men enrolled in the achieving cannabis cessation-evaluating N-acetylcysteine treatment (ACCENT) study

BACKGROUND AND OBJECTIVES

Recent evidence suggests that women may fare worse than men in cannabis trials with pharmacologic interventions. Identifying baseline clinical profiles of treatment-seeking cannabis-dependent adults could inform gender-specific treatment planning and development.

METHODS

The current study compared baseline demographic, cannabis use, and psychiatric factors between women (n = 86) and men (n = 216) entering the Achieving Cannabis Cessation-Evaluating N-acetylcysteine Treatment (ACCENT) study, a multi-site, randomized controlled trial conducted within the National Drug Abuse Treatment Clinical Trials Network.

RESULTS

Women reported greater withdrawal intensity (p = .001) and negative impact of withdrawal (p = .001), predominantly due to physiological and mood symptoms. Women were more likely to have lifetime panic disorder (p = .038) and current agoraphobia (p = .022), and reported more days of poor physical health (p = .006) and cannabis-related medical problems (p = .023). Women reporting chronic pain had greater mean pain scores than men with chronic pain (p = .006). Men and women did not differ on any measures of baseline cannabis use.

DISCUSSION AND CONCLUSIONS

Cannabis-dependent women may present for treatment with more severe and impairing withdrawal symptoms and psychiatric conditions compared to cannabis-dependent men. This might help explain recent evidence suggesting that women fare worse than men in cannabis treatment trials of pharmacologic interventions. Baseline clinical profiles of treatment-seeking adults can inform gender-specific treatment planning and development.

SCIENTIFIC SIGNIFICANCE

Cannabis-dependent women may benefit from integrated treatment focusing on co-occurring psychiatric disorders and targeted treatment of cannabis withdrawal syndrome.(Am J Addict 2017;26:136-144).