The prevalence of cannabis withdrawal and its influence on adolescents' treatment response and outcomes: a 12-month prospective investigation

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.

Intention to quit or reduce e-cigarettes, cannabis, and their co-use among a school-based sample of adolescents

INTRODUCTION

Little is known about the prevalence and predictors of adolescents' intention to quit or reduce use of e-cigarettes and/or cannabis.

METHODS

Frequencies of intention to change (quit, reduce) e-cigarettes and/or cannabis use were examined among 23,915 surveyed middle and high school students with sole and co-use. Predictors of intention to change were identified via LASSO/multilevel logistic regression.

RESULTS

Among those with sole e-cigarette use (n = 543), 40.9 % intended to quit and 24.1 % intended to reduce; non-daily e-cigarette use predicted intention to quit and reduce e-cigarettes (p's < 0.03). Among those with sole cannabis use (n = 546), 10.6 % intended to quit and 25.1 % intended to reduce; absence of cannabis cravings predicted intention to reduce cannabis use (p < 0.01). Among those with co-use (n = 816), 26.2 % intended to either quit or reduce (quit/reduce) both substances, 27.5 % intended to quit/reduce e-cigarettes only, and 6.9 % intended to quit/reduce cannabis only. No predictors emerged for intention to change e-cigarette use among those with co-use (p's > 0.09), but younger age, lack of poly-tobacco use, and lack of cannabis craving predicted intention to quit/reduce cannabis use (p's < 0.04).

CONCLUSIONS

More than half of adolescents with past-month e-cigarette use, regardless of concurrent cannabis use, expressed interest in changing their use. However, only heaviness of e-cigarette use emerged as a predictor of intention to change suggesting. While fewer students expressed interest in changing their cannabis use, cannabis cravings and poly-tobacco use predicted intent to change. Overall, findings emphasize the need to tailor interventions towards adolescents engaging in more problematic substance use patterns.

Validation of the Reasons for Quitting Smoking Cannabis Scale Among People with Cannabis Use Disorder

BACKGROUND

The prevalence of cannabis use disorder (CUD) has increased in the last ten years with medicinal and recreational legalization across the United States and increasing accessibility worldwide. Estimates suggest that 8-18% of individuals who use cannabis meet diagnostic criteria for CUD, leading to significant impairments across functioning. However, there are currently no measures that assess the reasons for quitting smoking cannabis to use in treatments with validation evidence in those with CUD.

METHOD

We validated the Reasons for Quitting Smoking Cannabis Scale (RQSCS) in adults (n = 133) who meet the diagnostic criteria for CUD as part of a laboratory-based clinical trial on transdermal nicotine patches for cannabis withdrawal symptoms (R01DA031006). We conducted standard psychometric testing, including exploratory factor analyses, estimating internal consistencies, exploring demographic variation, and testing construct validity.

RESULTS

The RQSCS demonstrated a four-factor structure, including: (1) cognitive health, (2) social functioning, (3) health problems, (4) reputation, and a single item that assesses experimental incentive; λs > .410), with acceptable to high internal consistencies for each subscale (αs > .725). The scale demonstrated strong construct validity and minor demographic variation. Finally, all subscales were sensitive to detecting reasons for quitting cannabis and differentially predicted cannabis use 31 days after the study.

CONCLUSION

The RQSCS is a psychometrically robust, timely instrument for assessing the reasons for quitting smoking cannabis in individuals with CUD. The scale has the potential to provide useful information for clinicians attempting to help those with CUD reduce or cease their cannabis use, informing individualized treatment plans and enhancing motivation for change.

Assessment of Withdrawal, Mood, and Sleep Inventories After Monitored 3-Week Abstinence in Cannabis-Using Adolescents and Young Adults

Introduction: Among adolescents and young adults, cannabis use is prevalent. Prior studies characterizing withdrawal effects in this age range have primarily included treatment seeking or comorbid psychiatric samples; these studies have identified several affected domains, especially sleep, mood, and anxiety. The present study compared a community (i.e., nontreatment seeking) sample of cannabis-using and control participants on mood, anxiety, sleep, and withdrawal inventories during the course of a monitored 3-week cannabis abstinence period. Materials and Methods: Seventy-nine adolescent and young adult participants (cannabis-using group=37 and control group=42) were recruited from the community to undergo 3 weeks of confirmed abstinence (i.e., urine and sweat patch toxicology) and completion of Cannabis Withdrawal Symptom Criteria, State-Trait Anxiety Inventory, Beck's Depression Inventory, and Pittsburgh Sleep Quality Index across the study period. Repeated measures and cross-sectional regressions were used to examine main effects of group and interactions with time (where appropriate), while accounting for recent alcohol use and cotinine levels. Results: Cannabis-using participants reported higher mood (p=0.006), overall withdrawal (p=0.009), and sleep-related withdrawal (p<0.001) symptoms across abstinence compared to controls. Overall withdrawal severity (p=0.04) and sleep-related withdrawal symptoms (p=0.02) demonstrated a quadratic trajectory across the monitored abstinence periods, with an increase from baseline and subsequent decreases in symptom severity. No differences of anxiety scores (p=0.07) or trajectories (p=0.18) were observed. By study completion, groups did not differ among sleep quality components (all p's>.05). Conclusions: These findings revealed that nontreatment-seeking cannabis-using adolescents and young adults reported heightened total withdrawal symptoms during a 3-week sustained abstinence period relative to controls. Cannabis-using participants demonstrated an increase in withdrawal symptom trajectory during the first week followed by decreased symptoms from weeks 2 to 3, which contrasts with prior linear decreases observed in cannabis-using adolescent and young adults. More mood symptoms were observed in the cannabis-using group even while excluding for comorbid psychopathologies-along with significantly more sleep problems during the abstinence period. Implications include the necessity to provide psychoeducation for recreational, nontreatment-seeking cannabis-using individuals about cannabis withdrawal, mood symptoms, and sleep quality difficulties when cannabis cessation is attempted, to improve likelihood of long-term sustained abstinence.

Marijuana use in children: An update focusing on pediatric tetrahydrocannabinol and cannabidiol use

Cannabis is the most used recreational drug in the United States, and its use is increasing among children and adolescents.  With the increase in legalized use, there have been increases in intentional and accidental cannabis exposure in the pediatric population. There is also minimized perceived risk.  We review the current use of cannabis and its derivatives, the drug effects and clinical presentation, common misconceptions, pharmacology, and epidemiology. Finally, we review some long-term consequences of cannabis use.

Clinical management of cannabis withdrawal

BACKGROUND AND AIMS

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

METHODS

Narrative review of literature.

RESULTS

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

CONCLUSIONS

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

Progression of cannabis withdrawal symptoms in people using medical cannabis for chronic pain

BACKGROUND AND AIMS

Research from cohorts of individuals with recreational cannabis use indicates that cannabis withdrawal symptoms are reported by more than 40% of those using regularly. Withdrawal symptoms are not well understood in those who use cannabis for medical purposes. Therefore, we prospectively examined the stability of withdrawal symptoms in individuals using cannabis to manage chronic pain.

DESIGN, SETTING, PARTICIPANTS

Using latent class analysis (LCA) we examined baseline cannabis withdrawal to derive symptom profiles. Then, using latent transition analysis (LTA) we examined the longitudinal course of withdrawal symptoms across the time points. Exploratory analyses examined demographic and clinical characteristics predictive of withdrawal class and transitioning to more or fewer withdrawal symptoms over time. A cohort of 527 adults with chronic pain seeking medical cannabis certification or re-certification was recruited between February 2014 and June 2015. Participants were recruited from medical cannabis clinic waiting rooms in Michigan, USA. Participants were predominantly white (82%) and 49% identified as male, with an average age of 45.6 years (standard deviation = 12.8).

MEASUREMENTS

Baseline, 12-month and 24-month assessments of withdrawal symptoms using the Marijuana Withdrawal Checklist-revised.

FINDINGS

A three-class LCA model including a mild (41%), moderate (34%) and severe (25%) symptom class parsimoniously represented withdrawal symptoms experienced by people using medical cannabis. Stability of withdrawal symptoms using a three-class LTA at 12 and 24 months ranged from 0.58 to 0.87, with the most stability in the mild withdrawal class. Younger age predicted greater severity and worsening of withdrawal over time.

CONCLUSIONS

Adults with chronic pain seeking medical cannabis certification or re-certification appear to experience mild to severe withdrawal symptoms. Withdrawal symptoms tend to be stable over a 2-year period, but younger age is predictive of worse symptoms and of an escalating withdrawal trajectory.

Prevalence of Cannabis Withdrawal Symptoms Among People With Regular or Dependent Use of Cannabinoids: A Systematic Review and Meta-analysis

IMPORTANCE

Cannabis withdrawal syndrome (CWS)-a diagnostic indicator of cannabis use disorder-commonly occurs on cessation of heavy and prolonged cannabis use. To date, the prevalence of CWS syndrome has not been well described, nor have the factors potentially associated with CWS.

OBJECTIVES

To estimate the prevalence of CWS among individuals with regular or dependent use of cannabinoids and identify factors associated with CWS.

DATA SOURCES

A search of literature from database inception to June 19, 2019, was performed using MEDLINE, Embase, PsycINFO, Web of Science, the Cumulative Index to Nursing and Allied Health Literature, ProQuest, Allied and Complementary Medicine, and Psychiatry online, supplemented by manual searches of reference lists of included articles.

STUDY SELECTION

Articles were included if they (1) were published in English, (2) reported on individuals with regular use of cannabinoids or cannabis use disorder as a primary study group, (3) reported on the prevalence of CWS or CWS symptoms using a validated instrument, (4) reported the prevalence of CWS, and (5) used an observational study design (eg, cohort or cross-sectional).

DATA EXTRACTION AND SYNTHESIS

All abstracts, full-text articles, and other sources were reviewed, with data extracted in duplicate. Cannabis withdrawal syndrome prevalence was estimated using a random-effects meta-analysis model, alongside stratification and meta-regression to characterize heterogeneity.

MAIN OUTCOMES AND MEASURES

Cannabis withdrawal syndrome prevalence was reported as a percentage with 95% CIs.

RESULTS

Of 3848 unique abstracts, 86 were selected for full-text review, and 47 studies, representing 23 518 participants, met all inclusion criteria. Of 23 518 participants included in the analysis, 16 839 were white (72%) and 14 387 were men (69%); median (SD) age was 29.9 (9.0) years. The overall pooled prevalence of CWS was 47% (6469 of 23 518) (95% CI, 41%-52%), with significant heterogeneity between estimates (I2 = 99.2%). When stratified by source, the prevalence of CWS was 17% (95% CI, 13%-21%) in population-based samples, 54% in outpatient samples (95% CI, 48%-59%), and 87% in inpatient samples (95% CI, 79%-94%), which were significantly different (P < .001). Concurrent cannabis (β = 0.005, P < .001), tobacco (β = 0.002, P = .02), and other substance use disorders (β = 0.003, P = .05) were associated with a higher CWS prevalence, as was daily cannabis use (β = 0.004, P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that cannabis withdrawal syndrome appears to be prevalent among regular users of cannabis. Clinicians should be aware of the prevalence of CWS in order to counsel patients and support individuals who are reducing their use of cannabis.

Behavioral Treatments for Adolescent Cannabis Use Disorder: a Rationale for Cognitive Retraining

Purpose of Review

Adolescent cannabis use represents a significant public health concern. Cannabis experimentation typically begins in adolescence and increases the odds of meeting criteria for cannabis use disorder. Cannabis use disorder is associated with numerous short- and long-term adverse consequences for adolescents, highlighting the critical need for efficacious behavioral treatments. This brief review aims to synthesize the state of the behavioral treatment literature on adolescents with cannabis use disorder and to discuss new pathways to leverage neuroscience to inform novel targets for behavioral intervention.

Recent Findings

To date, effective treatment options for adolescent cannabis use disorder that have been tested in randomized controlled trials include cognitive behavioral therapy, motivational enhancement therapy, and multidimensional family therapy. However, established behavioral treatment approaches focus on higher-order cognitive control and have only been modestly effective.

Summary

There is a need to develop new pathways that translate neuroscience findings into novel targets for behavioral interventions.

Engaging Youth (Adolescents and Young Adults) to Change Frequent Marijuana Use: Motivational Enhancement Therapy (MET) in Primary Care

PURPOSE

To characterize information elicited from adolescent/young adults with frequent cannabis use in Motivational Enhancement Therapy (MET), and determine whether differences exist across stages of change (SOC) for reducing use.

DESIGN AND METHODS

Primary care patients 15-24 years old using cannabis ≥3 times/week enrolled in a pilot randomized intervention trial. All youth were offered two 1-hour MET sessions. Content analysis was used to code and categorize main reasons for use, alternative behaviors, goals, values, pros and cons of change, and compared results between youth in Pre-Contemplation vs. Contemplation SOC.

RESULTS

Fifty-six youth completed MET session 1, 46 completed session 2. Most reported their main reason for use was related to emotional coping, negative feelings were a top-3 trigger, and distraction was an alternative way to meet their needs. Youth most frequently described progress in education or career/job as 1-year goals. More than half identified family as a very important value. They most frequently reported pros of using less related to achieving goals, self-improving, and saving money, and a con related to stress/coping. Compared to youth in Pre-Contemplation SOC, those in Contemplation were more likely to identify relationships as both a pro and con of using less cannabis.

CONCLUSIONS

MET can reveal developmentally appropriate goals, healthy values, and ambivalence about cannabis use that can be used to facilitate movement along the stages of behavior change toward reduction/cessation.

PRACTICE IMPLICATIONS

Brief motivational therapy can be used in primary care to gather information important in helping youth to reduce cannabis use.

DSM-5 cannabis withdrawal syndrome: Demographic and clinical correlates in U.S. adults

BACKGROUND

Cannabis withdrawal syndrome (CWS) was newly added to the Diagnostic and Statistical Manual of Mental Disorders in its most recent edition, DSM-5. With cannabis use increasing among U.S. adults, information is needed about the prevalence and correlates of DSM-5 CWS in the general population. This study presents nationally representative findings on the prevalence, sociodemographic and clinical correlates of DSM-5 CWS among U.S. adults.

METHOD

Participants ≥18 years were interviewed in the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III) in 2012-2013. Among the sub-sample of frequent cannabis users in the prior 12 months (≥3 times a week; N = 1527), the prevalence and demographic and clinical correlates of DSM-5 CWS were examined.

RESULTS

In frequent cannabis users, the prevalence of CWS was 12.1%. The most common withdrawal symptoms among those with CWS were nervousness/anxiety (76.3%), hostility (71.9%), sleep difficulty (68.2%) and depressed mood (58.9%). CWS was associated with significant disability (p < 0.001), and with mood disorders (adjusted odds ratios [aOR] = 1.9-2.6), anxiety disorders (aOR = 2.4-2.5), personality disorders (aOR = 1.7-2.2) and family history of depression (aOR = 2.5) but not personal history of other substance use disorders or family history of substance use problems.

CONCLUSIONS

CWS is highly comorbid and disabling. Its shared symptoms with depressive and anxiety disorders call for clinician awareness of CWS and the factors associated with it to promote more effective treatment among frequent cannabis users.

Cognitive and Mental Health Predictors of Withdrawal Severity During an Active Attempt to Cut Down Cannabis Use

A milestone in cannabis research is the establishment of a clinically relevant cannabis withdrawal syndrome, yet little is known about the underlying mechanisms. We investigated the predictive role of mental health and cognitive factors in withdrawal severity during an active attempt to cut down, relative to uninterrupted cannabis use. Ninety heavy cannabis users were randomly assigned to an experimental or control group. The experimental group was asked to cut down substance use for 1 week. Past week substance use, substance use-related problems, depressive symptoms, cravings, and cognitive control were assessed at baseline. Past week substance use and withdrawal severity were assessed at follow-up. The experimental group reduced their cannabis use more and experienced more withdrawal than the control group. Hierarchical regression analysis per predictor indicated that cannabis use-related problems, depressive symptoms, and cannabis craving, but not cognitive control, predicted stronger withdrawal. Craving uniquely predicted withdrawal in the experimental group. A combined hierarchical regression indicated that only depressive symptoms and cannabis use-related problems uniquely predicted withdrawal across groups. These results suggest that depressive symptoms and cannabis use-related problems are generally indicative of cannabis withdrawal severity, whereas craving specifically predicts cannabis withdrawal during an active attempt to cut-down cannabis use.

US Epidemiology of Cannabis Use and Associated Problems

This review provides an overview of the changing US epidemiology of cannabis use and associated problems. Adults and adolescents increasingly view cannabis as harmless, and some can use cannabis without harm. However, potential problems include harms from prenatal exposure and unintentional childhood exposure; decline in educational or occupational functioning after early adolescent use, and in adulthood, impaired driving and vehicle crashes; cannabis use disorders (CUD), cannabis withdrawal, and psychiatric comorbidity. Evidence suggests national increases in cannabis potency, prenatal and unintentional childhood exposure; and in adults, increased use, CUD, cannabis-related emergency room visits, and fatal vehicle crashes. Twenty-nine states have medical marijuana laws (MMLs) and of these, 8 have recreational marijuana laws (RMLs). Many studies indicate that MMLs or their specific provisions did not increase adolescent cannabis use. However, the more limited literature suggests that MMLs have led to increased cannabis potency, unintentional childhood exposures, adult cannabis use, and adult CUD. Ecological-level studies suggest that MMLs have led to substitution of cannabis for opioids, and also possibly for psychiatric medications. Much remains to be determined about cannabis trends and the role of MMLs and RMLs in these trends. The public, health professionals, and policy makers would benefit from education about the risks of cannabis use, the increases in such risks, and the role of marijuana laws in these increases.

Prolonged cannabis withdrawal in young adults with lifetime psychiatric illness

Young adults with psychiatric illnesses are more likely to use cannabis and experience problems from use. It is not known whether those with a lifetime psychiatric illness experience a prolonged cannabis withdrawal syndrome with abstinence. Participants were fifty young adults, aged 18-25, recruited from the Boston-area in 2015-2016, who used cannabis at least weekly, completed the Structured Clinical Interview for DSM-IV to identify Axis I psychiatric diagnoses (PD+ vs PD-), and attained cannabis abstinence with a four-week contingency management protocol. Withdrawal symptom severity was assessed at baseline and at four weekly abstinent visits using the Cannabis Withdrawal Scale. Cannabis dependence, age of initiation, and rate of abstinence were similar in PD+ and PD- groups. There was a diagnostic group by abstinent week interaction, suggesting a difference in time course for resolution of withdrawal symptoms by group, F(4,46)=3.8, p=0.009, controlling for sex, baseline depressive and anxiety symptoms, and frequency of cannabis use in the prior 90days. In post hoc analyses, there was a difference in time-course of cannabis withdrawal. PD- had significantly reduced withdrawal symptom severity in abstinent week one [t(46)=-2.2, p=0.03], while PD+ did not report improved withdrawal symptoms until the second abstinent week [t(46)=-4.1, p=0.0002]. Cannabis withdrawal symptoms improved over four weeks in young people with and without a lifetime psychiatric diagnosis. However, those with a psychiatric illness reported one week delayed improvement in withdrawal symptom severity. Longer duration of cannabis withdrawal may be a risk factor for cannabis dependence and difficulty quitting.

The consequences of chronic cannabis smoking in vulnerable adolescents

Cannabis, like the mythic shape-shifter, presents in various guises, morphing with the perspective and context of the observer. Arguments about cannabis are confused by a myriad of debates-medical, social, ethical and political-as if a single conceptual umbrella can capture the variety and granularity of marijuana-related issues. This paper responds to marijuana use as it is commonly practised by youth in Australia. It has little to say about synthetic cannabinoids, specific medicinal cannabinoids, or medicinal properties of marijuana. We address those adolescents genetically and environmentally vulnerable to mental illness, with specific emphasis on indigenous and neurodevelopmentally impaired young people who show patterns of usage and response very different to adults and more resilient members of the population. Specifically, the practice of mixing tobacco with marijuana by aboriginal youth, and the resultant coalition of dependencies, will likely presage a rise in pulmonary and central nervous system pathology over the coming decades. Aboriginal youth begin using earlier, persist longer, and take greater quantities of cannabis than non-indigenous youth. This paper recommends practical interventions to reduce the multiple health consequences of chronic cannabis use in young people, especially indigenous young people.

Cannabis Withdrawal: A Review of Neurobiological Mechanisms and Sex Differences

PURPOSE OF REVIEW

This report provides an updated overview of pre-clinical and clinical research on the etiology and biological substrates of the cannabis withdrawal syndrome.

RECENT FINDINGS

Long-term cannabis use is associated with downregulation of type-1 cannabinoid receptors (CB1). Reduced CB1 receptor density is related to increased withdrawal during early abstinence, and the reduction in CB1 receptor density reverses with extended abstinence. Females have been shown to have increased rate and severity of a subset of cannabis withdrawal symptoms compared with men.

SUMMARY

Recent studies have extended knowledge of the biological processes and individual difference variables that influence cannabis withdrawal. However, caveats include small sample sizes in clinical studies, participant samples that are predominantly male, and limited examinations of endocannabinoids, enzymes that degrade endocannabinoids, negative allosteric modulators, and other neurobiological systems that may directly impact cannabis withdrawal symptom expression.

The cannabis withdrawal syndrome: current insights

The cannabis withdrawal syndrome (CWS) is a criterion of cannabis use disorders (CUDs) (Diagnostic and Statistical Manual of Mental Disorders - Fifth Edition) and cannabis dependence (International Classification of Diseases [ICD]-10). Several lines of evidence from animal and human studies indicate that cessation from long-term and regular cannabis use precipitates a specific withdrawal syndrome with mainly mood and behavioral symptoms of light to moderate intensity, which can usually be treated in an outpatient setting. Regular cannabis intake is related to a desensitization and downregulation of human brain cannabinoid 1 (CB1) receptors. This starts to reverse within the first 2 days of abstinence and the receptors return to normal functioning within 4 weeks of abstinence, which could constitute a neurobiological time frame for the duration of CWS, not taking into account cellular and synaptic long-term neuroplasticity elicited by long-term cannabis use before cessation, for example, being possibly responsible for cannabis craving. The CWS severity is dependent on the amount of cannabis used pre-cessation, gender, and heritable and several environmental factors. Therefore, naturalistic severity of CWS highly varies. Women reported a stronger CWS than men including physical symptoms, such as nausea and stomach pain. Comorbidity with mental or somatic disorders, severe CUD, and low social functioning may require an inpatient treatment (preferably qualified detox) and post-acute rehabilitation. There are promising results with gabapentin and delta-9-tetrahydrocannabinol analogs in the treatment of CWS. Mirtazapine can be beneficial to treat CWS insomnia. According to small studies, venlafaxine can worsen the CWS, whereas other antidepressants, atomoxetine, lithium, buspirone, and divalproex had no relevant effect. Certainly, further research is required with respect to the impact of the CWS treatment setting on long-term CUD prognosis and with respect to psychopharmacological or behavioral approaches, such as aerobic exercise therapy or psychoeducation, in the treatment of CWS. The up-to-date ICD-11 Beta Draft is recommended to be expanded by physical CWS symptoms, the specification of CWS intensity and duration as well as gender effects.

Ambivalence: Prerequisite for success in motivational interviewing with adolescents?

BACKGROUND AND AIMS

The exploration and resolution of ambivalence play an essential role in motivational interviewing (MI) theory. However, most adolescent MI studies have not examined ambivalence as a contributor to behaviour change. This paper reviewed research findings on the role of ambivalence in the adolescent change process.

METHODS AND RESULTS

We undertook a narrative review of the published empirical and theoretical literature on ambivalence and mechanisms of change in MI for adolescents and found that current MI evaluations appear not to have access to reliable and valid measures of ambivalence in adolescence or neuroimaging methods to evaluate the mechanisms of treatment response.

CONCLUSIONS

Improved instrumentation is needed to assess adolescents' ambivalence in clinical and research settings. Innovative methodology, including neuroimaging, may help identify factors mediating relationships between adolescents' ambivalence and treatment response.

Cannabis Withdrawal, Posttreatment Abstinence, and Days to First Cannabis Use Among Emerging Adults in Substance Use Treatment: A Prospective Study

Very little prospective research investigates how cannabis withdrawal is associated with treatment outcomes, and this work has not used the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) thresholds for cannabis withdrawal. The sample included 110 emerging adults entering outpatient substance use treatment who were heavy cannabis users with no other drug use and limited alcohol use. We used survival analyses to predict days to first use of cannabis and logistic regression to predict whether participants were abstinent and living in the community at 3 months. Those meeting criteria for cannabis withdrawal were more likely to return to use sooner than those not meeting criteria for cannabis withdrawal. However, the presence of cannabis withdrawal was not a significant predictor of 3-month abstinence. Emerging adults with DSM-5 cannabis withdrawal may have difficulty initiating abstinence in the days following their intake assessment, implying the need for strategies to mitigate their more rapid return to cannabis use.

Memory Systems and the Addicted Brain

The view that anatomically distinct memory systems differentially contribute to the development of drug addiction and relapse has received extensive support. The present brief review revisits this hypothesis as it was originally proposed 20 years ago (1) and highlights several recent developments. Extensive research employing a variety of animal learning paradigms indicates that dissociable neural systems mediate distinct types of learning and memory. Each memory system potentially contributes unique components to the learned behavior supporting drug addiction and relapse. In particular, the shift from recreational drug use to compulsive drug abuse may reflect a neuroanatomical shift from cognitive control of behavior mediated by the hippocampus/dorsomedial striatum toward habitual control of behavior mediated by the dorsolateral striatum (DLS). In addition, stress/anxiety may constitute a cofactor that facilitates DLS-dependent memory, and this may serve as a neurobehavioral mechanism underlying the increased drug use and relapse in humans following stressful life events. Evidence supporting the multiple systems view of drug addiction comes predominantly from studies of learning and memory that have employed as reinforcers addictive substances often considered within the context of drug addiction research, including cocaine, alcohol, and amphetamines. In addition, recent evidence suggests that the memory systems approach may also be helpful for understanding topical sources of addiction that reflect emerging health concerns, including marijuana use, high-fat diet, and video game playing.

The influence of cannabinoids on learning and memory processes of the dorsal striatum

Extensive evidence indicates that the mammalian endocannabinoid system plays an integral role in learning and memory. Our understanding of how cannabinoids influence memory comes predominantly from studies examining cognitive and emotional memory systems mediated by the hippocampus and amygdala, respectively. However, recent evidence suggests that cannabinoids also affect habit or stimulus-response (S-R) memory mediated by the dorsal striatum. Studies implementing a variety of maze tasks in rats indicate that systemic or intra-dorsolateral striatum infusions of cannabinoid receptor agonists or antagonists impair habit memory. In mice, cannabinoid 1 (CB1) receptor knockdown can enhance or impair habit formation, whereas Δ(9)THC tolerance enhances habit formation. Studies in human cannabis users also suggest an enhancement of S-R/habit memory. A tentative conclusion based on the available data is that acute disruption of the endocannabinoid system with either agonists or antagonists impairs, whereas chronic cannabinoid exposure enhances, dorsal striatum-dependent S-R/habit memory. CB1 receptors are required for multiple forms of striatal synaptic plasticity implicated in memory, including short-term and long-term depression. Interactions with the hippocampus-dependent memory system may also have a role in some of the observed effects of cannabinoids on habit memory. The impairing effect often observed with acute cannabinoid administration argues for cannabinoid-based treatments for human psychopathologies associated with a dysfunctional habit memory system (e.g. post-traumatic stress disorder and drug addiction/relapse). In addition, the enhancing effect of repeated cannabinoid exposure on habit memory suggests a novel neurobehavioral mechanism for marijuana addiction involving the dorsal striatum-dependent memory system.