Assessment of cannabis use disorders: a systematic review of screening and diagnostic instruments

Conceptualizing problematic use of medicinal Cannabis: Development and preliminary validation of a brief screening questionnaire

The use of Medicinal Cannabis (MC) for treating chronic pain is increasing, globally, yet the definition of problematic MC use remains unclear. Defining problematic use of cannabis in medical and non-medical contexts may be fundamentally different since individuals prescribed MC often experience physical dependence, which do not necessarily imply pathology. We aimed to conceptualize problematic use of MC and develop a brief questionnaire for identifying and quantifying problematic MC use. Content validation used a broad definition of problematic substance use, adapting and compiling an initial list of 36 items from various sources: (a) screening tools for assessing problematic prescription opioid medication use; (b) screening tools for problematic recreational cannabis use and (c) qualitative interviews with MC patients. 390 American self-identified chronic pain patients holding a MC card rated each item from the initial list on a 5-point frequency scale and filled out questionnaires assessing various clinical outcomes. Following initial item titration, a multi-group measurement invariance comparison strategy, using two external indicators: alcohol-related problems and depression, resulted a final eight-item list that met fit quality in a baseline model, presented excellent internal consistency reliability (α = 0.929), and significantly correlated with anxiety and low quality of life. Items in the final list related predominantly to negative consequences of MC use. Problematic use of MC is characterized by negative physiological, social, emotional and functional consequences. The final eight-item list was named the Medicinal Cannabis Negative Consequences Scale (MCNCS), emerging as a brief measure for problematic MC use and demonstrating preliminary reliability and validity, which could aid clinicians and researchers.

Life-course Accumulated Cannabis Use and Recent Cannabis-related Problems in the Washington Panel Survey

BACKGROUND

Previous studies have only investigated the short-term association of recent cannabis use with cannabis-related problems, without accounting for the onset, duration, and variations in frequency of use in the life-course.

METHODS

We obtained data from the Washington panel survey during 2014-2016. We constructed accumulated lifetime exposure to cannabis use, heavy drinking (5+ drinks on one occasion), and cigarette pack-years from age of onset based on a series of decades-based questions on cannabis use and heavy drinking, and tobacco use history. We used Generalized Estimating Equation with Poisson distribution to investigate the association between accumulated cannabis use and the past-6-month CUDIT score. We adjusted for accumulated heavy drinking and cigarette pack-years, substance co-use variables, demographics, and applied survey weights.

RESULTS

We found strong and statistically significant correlations for the lifetime measures across the four panel surveys, indicating that the life-course measures of cannabis use and heavy drinking were largely reliable. We found a statistically significant relationship between the lifetime accumulated exposure to cannabis and CUDIT. The results were robust to the inconsistencies in reported frequencies and onset age across panel surveys.

CONCLUSIONS

This study established the relationship between lifetime exposure to cannabis and cannabis-related problems in a representative sample of drinkers and marijuana users in Washington state. We have also provided test-retest validity and question details for the decades-based cannabis and heavy drinking measures to facilitate their use in future studies of cannabis and alcohol-related outcomes.

Latent classes of alcohol and cannabis use among adults with binge-spectrum eating disorders: Associations with eating disorder symptom severity and personality features

OBJECTIVE

Alcohol and cannabis use are prevalent among individuals with binge-spectrum eating disorders (B-ED) and vary in terms of frequency and associated problems. The current study aimed to identify latent classes of alcohol and cannabis use patterns among B-ED and examine associations between latent classes and demographic characteristics, eating disorder symptoms, and personality features.

METHODS

Participants (N = 236) were treatment-seeking adults with B-ED who completed a clinical interview of eating pathology and self-report measures of alcohol and cannabis use in the past 3 months, alcohol and cannabis-related problems, and personality features (i.e., impulsivity, affect lability).

RESULTS

Latent class analysis identified three heterogeneous classes, labelled as (a) Low Alcohol, (b) Moderate Drinking and Problems with Occasional Cannabis Use, and (c) No Alcohol and Cannabis Use. Latent classes significantly differed in terms of substance use engagement and problems, demographic characteristics, dietary restraint, impulsive personality features, and affect lability.

CONCLUSIONS

Study findings support heterogeneity in alcohol and cannabis use among B-ED and suggest patient characteristics and clinical severity associated with specific substance use presentations. Future research should replicate results using larger, diverse samples engaging in a broader range of alcohol and cannabis use symptoms.

Psychometric properties of the cannabis abuse screening test (CAST) in a sample of Moroccans with cannabis use

BACKGROUND

The Cannabis Abuse Screening Test (CAST) is a widely used screening tool for identifying patterns of cannabis use that have negative health or social consequences for both the user and others involved. This brief screening instrument has been translated into multiple languages, and several studies examining its psychometric properties have been published. However, studies on the factorial validity and psychometric properties of a Moroccan version of the CAST are not yet available. The objective of this study is to validate the CAST, translated, and adapted to the Moroccan Arabic dialect among persons with cannabis use.

METHODS

A total of 370 participants from an addictology center in Fez City, were selected over two phases to form the study sample. First, in phase I, exploratory factor analysis was employed to evaluate the factor structure in the pilot sample (n1 = 150). Subsequently, in the second phase (Phase II), confirmatory factor analysis was utilized to confirm this structure in the validation sample (n2 = 220). All statistical analyses were carried out using the R program.

RESULTS

The CFA unveiled a three-factor structure that showed a good overall fit (χ2/df = 2.23, RMSEA = 0.07, SRMR = 0.02, CFI = 0.99, NFI = 0.98) and satisfactory local parameters (standardized factor loadings between 0.72 and 0.88). The model demonstrates satisfactory reliability and convergent validity, as evidenced by the acceptable values of composite reliability (CR) (0.76-0.88) and average variance extracted (AVE) (0.62-0.78), respectively. The square roots of the AVE exceeded the correlations of the factor pairs, and the heterotrait-monotrait (HTMT) ratio of the correlation values was below 0.85, indicating acceptable discriminant validity.

CONCLUSION

The reliability, convergent validity, and discriminant validity tests all demonstrated that the Moroccan version of the CAST performed well and can be considered a valid tool for screening of problematic cannabis use.

Recreational cannabis policy reform-What mental health nurses need to know about minimising harm and contributing to the reform debate

The recently rapidly evolving legal status of recreational cannabis in various countries has triggered international debate, particularly around measures required to minimise resulting harms. The present article argues that mental health nurses should have a key role in promoting safe and appropriate use of recreational cannabis, and minimising harm based on the extant evidence. The article summarises the factors driving legalisation, outlines the evident medicinal benefits of cannabis, and appraises the evidence on the negative mental health impacts associated with use. We go on to discuss research findings on the potentially deleterious mental health effects resulting from legalising recreational cannabis and strategies to minimise these harms, including directions for future research and evaluation. Further, we consider the importance of the implementation of harm minimisation measures that are context-specific, using Thailand as an example. Finally, we present the key health promotion messages that mental health nurses should aim to convey to people who use or consider using recreational cannabis. Ultimately, we aim to provide a summary of the existing evidence that mental health nurses can draw upon to promote mental health and engage with the policy reform debate.

Self-regulation profiles in addictive behaviors among adolescents: A transdiagnostic approach

Dual-pathway models suggest that poor self-regulation (immature regulatory combined with strong reactive processes) is an important factor underlying addictive behaviors among adolescents. This study examined whether there are different self-regulation profiles among community adolescents, and how these profiles are related to the presence, severity and comorbidity of different addictive behaviors. A community sample of 341 adolescents (54.5% female; 13-17 years) was recruited. Participants self-reported on regulatory (inhibitory control) and reactive (reward and punishment sensitivity) processes, as well as on different addictive behaviors (binge eating, tobacco-, cannabis- and alcohol use, gaming, gambling and pathological buying). A model-based clustering analysis found evidence for three meaningful profiles: 'impulsive/under-controlled', 'anxious' and 'protective'. The 'impulsive/under-controlled' profile was characterized by the highest prevalence and severity of cannabis use and the most severe alcohol use. The 'impulsive/under-controlled' and 'protective' profiles demonstrated the highest prevalence and severity of tobacco use, whereas the 'impulsive/under-controlled' and 'anxious' profiles showed the highest binge eating scores. Adolescents who reported more than three types of addictive behaviors generally belonged to the 'impulsive/under-controlled' profile. The profiles did not differ for gaming, gambling and pathological buying. The 'impulsive/under-controlled' profile emerged as the most vulnerable profile in the context of addictive behaviors (especially for binge eating and substance use).

Awareness and interest in cannabis use for cancer management among cancer survivors

BACKGROUND

We examined the awareness, interest, and information sources relating to cannabis use for cancer management (including management of cancer symptoms and treatment-related side effects) and determined factors associated with cancer survivors' awareness and interest in learning about cannabis use for cancer management.

METHODS

This was a cross-sectional study of adult cancer survivors (N = 1886) receiving treatment at a comprehensive cancer center. Weighted prevalence and multivariable logistic regression analyses were conducted.

RESULTS

Among cancer survivors, 88% were aware and 60% were interested in learning about cannabis use for cancer management. Common sources of information to learn about cannabis use for cancer management were cancer doctors/nurses (82%), other patients with cancer (27%), websites/blogs (26%), marijuana stores (20%), and family/friends (18%). The odds of being aware of cannabis use for cancer management was lower among male compared to female survivors (adjusted odds ratio [AOR]: 0.61; 95% confidence interval [CI]: 0.41-0.90), non-Hispanic Blacks compared to non-Hispanic Whites (AOR: 0.36; 95% CI: 0.21-0.62), and survivors who do not support the legalization of cannabis for medical use compared to those who do (AOR: 0.10; 95% CI: 0.04-0.23). On the other hand, the odds of being interested in cannabis use for cancer management was higher among non-Hispanic Blacks compared to non-Hispanic Whites (AOR: 1.65; 95% CI: 1.04-2.62), and among cancer survivors actively undergoing cancer treatment compared to patients on non-active treatment (AOR: 2.25; 95% CI: 1.74-2.91).

CONCLUSION

Awareness of cannabis use for cancer management is high within the cancer survivor population. Results indicated health care providers are leading information source and should receive continued medical education on cannabis-specific guidelines. Similarly, tailored educational interventions are needed to guide survivors on the benefits and risks of cannabis use for cancer management.

Prevalence, reasons for use, perceived benefits, and awareness of health risks of cannabis use among cancer survivors - implications for policy and interventions

BACKGROUND

There is increasing discourse on the use of cannabis as a palliative for cancer/cancer-treatment-related symptoms. We described the prevalent reasons for use, perceived benefits, and awareness of health risks from cannabis use for cancer management among cancer survivors.

METHODS

Cross-sectional survey of adult (≥ 18 years) cancer survivors from 41 US states receiving treatment at a comprehensive cancer center.

RESULTS

Of 1,886 cancer survivors included, 17.4% were current users, 30.5% were former users, and 52.2% were never users of cannabis. Among survivors who currently or formerly used cannabis after their cancer diagnosis (n = 510), the reasons for cannabis use in cancer management were; sleep disturbance (60%), pain (51%), stress (44%), nausea (34%), and mood disorder/depression (32%). Also, about a fifth (91/510) of survivors used cannabis to treat their cancer. Across the different symptoms assessed, over half of the survivors who reported a reason for using cannabis currently or after their cancer diagnosis perceived that cannabis was helpful to a great extent in improving their symptoms. However, of the 167 survivors who reported awareness of potential health risks from cannabis use, the awareness of adverse health risks associated with cannabis use was low: suicidal thoughts (5%), intense nausea and vomiting (6%), depression (11%), anxiety (14%), breathing problems (31%), and interaction with cancer drugs (35%).

CONCLUSION

Prevalence of cannabis use among survivors was notable, with most reporting a great degree of symptomatic improvement for the specified reason for use. However, only a few were aware of the health risks of cannabis use during cancer management.

IMPLICATIONS FOR CANCER SURVIVORS

With more cancer survivors using cannabis as a palliative in managing their cancer-related symptoms, future guidelines and policies on cannabis use in cancer management should incorporate cannabis-based interventions to minimize the inadvertent harm from cannabis use during cancer treatment among survivors.

Cannabis Use among Cancer Survivors: Use Pattern, Product Type, and Timing of Use

Despite growing interest in the use of cannabis for the treatment of cancer-related symptoms, there are limited studies that have assessed the use pattern, type, and mode of delivery of cannabis products used by cancer survivors. This study describes the current state of the use pattern, product type, and mode of delivery of cannabis used by cancer survivors. This was a cross-sectional study of cancer survivors from 41 U.S. states who received treatment at the largest NCI-designated comprehensive cancer center. The weighted prevalence of the use patterns, product types, and modes of delivery of cannabis used by cancer survivors was estimated. A total of 1886 cancer survivors were included in the study, with 915 (48% [95% CI: 45-51]) reporting ever using cannabis. Of survivors who had ever used cannabis, 36% (95% CI: 33-40) were current users. Among survivors who reported cannabis use after diagnosis, 40% used cannabis during and after cancer treatment, 35% used cannabis during treatment, and 25% used cannabis after completing their cancer treatment. Additionally, 48% of survivors reported an increase in cannabis use since cancer diagnosis. The commonest types of cannabis products used by cancer survivors were dry leaf cannabis (71%), cannabidiol (CBD) oil (46%), and cannabis candy (40%). Moreover, cancer survivors frequently used baked goods (32%), creams and gels (21%), and tinctures (18%). Furthermore, among ever users, the predominant mode of use was cannabis inhalation/smoking (69%) compared to eating/drinking (59%). More so, the common mode of inhalation/smoking of cannabis products were rolled cannabis cigarettes (79%), pipes (36%), water pipes (34%), vaporizers or vapes (14%), and e-cigarette devices (14%). A substantial number of cancer survivors use cannabis during cancer treatment, with increased use following cancer diagnosis. The forms and modes of delivery of cannabis varied among survivors, with most survivors inhaling or smoking cannabis. There is a need to educate healthcare providers (HCPs) and survivors on current evidence of cannabis use and strengthen cannabis regulatory frameworks to optimize benefits and minimize adverse events from cannabis use during cancer treatment.

A Pragmatic, Person-Centered View of Cannabis in the United States: Pursuing Care That Transcends Beliefs

BACKGROUND

Rates of cannabis use are increasing in the United States, likely as a result of changes in societal attitudes and expanding legalization. Although many patients report wanting to discuss the risks and benefits of cannabis use with their clinical providers, many providers hold conflicting beliefs regarding cannabis use and often do not engage patients in discussion about cannabis. This dilemma is underscored by the limitations imposed on cannabis related research, and lack of empirically based best-practice guidelines for clinicians when addressing cannabis use with patients.

OBJECTIVES

We aimed to briefly summarize clinician and patient attitudes toward cannabis use and review current clinical guidelines and provide suggestions to assist health care providers and clinicians in increasing their comfort and skill in discussing cannabis use with patients.

METHODS

A narrative review on attitudes toward cannabis use and clinical guidelines was performed to summarize the literature and provide evidence-based recommendations.

RESULTS

Attitudes toward cannabis use have been shaped by personal and political factors and contribute to clinician hesitance in speaking with patients about the topic. Administrative barriers have hindered the development of clearer public health guidelines that might enable the dissemination of evidence-based information on the health effects of cannabis use and might ultimately lead to better health outcomes.

CONCLUSION

Not discussing cannabis use with patients may be a crucial missed opportunity for harm reduction. In the absence of empirically supported best-practice guidelines, a person-centered approach can facilitate conversations on the harms and benefits of cannabis use.

Measuring cannabis quantities in online surveys: A rapid review and proposals for ways forward

OBJECTIVES

Cannabis use quantities are relevant for determining cannabis-related harms. This research aims to provide an overview of the available methods to assess quantities through self-report.

METHODS

A rapid review of various strategies to collect information on cannabis use quantities through self-report. Two independent literature searches resulted in n = 38 studies included for review.

RESULTS

A total of n = 14 studies employed methods for collecting cannabis use quantities that are not suitable for online surveys (e.g., rolling a fake joint). Of the remaining n = 24 studies with items that are suitable for online surveys, the quantity assessment was performed in three different ways. The data collection was either carried out by asking (a) for the total number of joints (i.e., crude joint method), (b) for the total weight (i.e., crude weight method), or (c) for specific products separately, for example, for the amount of flower and resin (i.e., product-specific method). In only n = 8 studies, cannabis use quantities were ascertained by providing visual aids (e.g., illustration of various amounts of flower).

CONCLUSIONS

The crude joint method and the product-specific method are the two most promising methods to collect information on cannabis use quantities. Using visual aids may potentially improve the accuracy of those methods.

Assessing the diagnostic utility of the Cannabis Use Disorder Identification Test - Revised (CUDIT-R) among veterans with medical and non-medical cannabis use

BACKGROUND

Few studies examine the utility of the Cannabis Use Disorder Identification Test - Revised (CUDIT-R) in relation to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, (DSM-5) criteria for cannabis use disorder (CUD). This study assesses the performance of the CUDIT-R among a sample of Veterans with and without medical cannabis use.

METHODS

We approached and consented primary care patients presenting to one of three Department of Veterans Affairs (VA) Medical Centers. Veterans with at least monthly cannabis use and complete CUD data at baseline were included in this analysis (n=234). CUDIT-R scores were compared against Alcohol Use Disorder and Associated Disabilities Interview Schedule-5 (DSM-5) CUD as the standard to calculate measures of validity (sensitivity, specificity), identify optimal CUDIT-R cutoff values, and assess the diagnostic proficiency of the CUDIT-R using receiver operating characteristic (ROC) curves. We further stratified analyses by active medical cannabis card holder status and DSM-5 CUD severity (any, moderate, and severe).

RESULTS

Among the entire sample, 38.9% qualified for any DSM-5 CUD, with 10.7% and 3.0% meeting criteria for moderate and severe CUD, respectively. We identified optimal CUDIT-R scores at 10 for any DSM-5 CUD (sensitivity=0.58; specificity=0.80), at 12 for moderate CUD (sensitivity=0.72; specificity=0.82), and at 14 for severe CUD (sensitivity=0.71; specificity=0.87). ROC curves showed higher CUDIT-R validity among non-card holders compared with medical cannabis card holders.

CONCLUSION

The present study identified optimal CUDIT-R cutoff scores for Veterans who use cannabis. Varying DSM-5 validity measures inform the need for population-specific CUDIT-R cutoff values.

Induced negative affect's impact on self-reported cannabis use, expectancies, and problems

Substance use disorders and affective disturbances often covary. Even momentary experiences of negative affect (NA) appear linked with substance use. While strong evidence of these relations exists, NA might bias endorsements of substance use due to hindered recall and reporting processes. This hypothesis warrants further research, as accurate assessment of substance-related variables is crucial in both research and treatment settings. The present study examined the influence of NA on reporting of cannabis variables using an affect-induction paradigm. Over 700 individuals recruited from Amazon's MTurk participated. After reporting demographics and baseline affect, participants were randomly assigned to either a NA induction or control condition. Follow-up measures assessed post-induction affect and cannabis-related variables. Results revealed that the NA induction task significantly increased NA and decreased positive affect relative to the control condition. Participants assigned to the NA induction reported greater negative cannabis expectancies and more cannabis problems, even after controlling for age and educational attainment. Cannabis use and cannabis problems appeared positively related. Future research should continue to assess for the influence of NA in reporting of cannabis variables. Should subsequent work find differences in reporting of substance use that appear to covary with negative affect, clinicians and researchers alike should be mindful of the implications of potentially biased reporting on assessment, intervention, and research outcomes.

Measurement of public health impacts of cannabis legalization in Canada to reflect policy maker priorities: A rapid scoping review of instruments and content domains

BACKGROUND

We were engaged by policy stakeholders to undertake a scoping review of cannabis measurement instruments to inform the evaluation of cannabis legalization impacts. We identified instruments employed in population-based or clinical research to screen and assess cannabis use, including measurement properties. We also identified the content domains included in each instrument and gaps in the measurement of key priority areas as established by policy stakeholders.

METHODS

We followed PRISMA and conducted searches on MEDLINE, PsycINFO, Web of Science, EMBASE, HAPI, Scopus and grey literature. We included publications from the past 15 years that reported the use of an instrument to measure cannabis use. Six study team members calibrated screening and data abstraction, independently identified records and abstracted data.

RESULTS

Across 915 included publications, we identified 187 unique instruments covering seven content domains and 35 subdomains. The most identified instruments were the Composite International Diagnostic Interview, the Timeline Follow-Back and the National Epidemiologic Survey on Alcohol and Related Conditions (109/915; 91/915; 64/915). The Canadian Cannabis Survey addressed the most subdomains (22/35). Frequency of use, prevalence of use, and mental health impacts were the most addressed subdomains (110/187; 94/187; 67/187) and storage, growing cannabis, and second-hand exposure were the least addressed (1/187; 4/187; 6/187).

CONCLUSION

This research identified instruments and domains critical to the assessment of public health impacts of cannabis legalization, which can facilitate the harmonization of measures to inform policy development. Future research should develop new instruments for less commonly-addressed constructs and thoroughly explore psychometric properties of existing instruments.

Impaired motor cortical plasticity associated with cannabis use disorder in young adults

Maladaptive cortical plasticity has been described in individuals with heroin and methamphetamine addiction and may mediate other substance abuse disorders. It is unknown whether cannabis dependence in humans alters the capacity for induction of cortical plasticity. The aim of this study was to non-invasively investigate cortical plasticity with transcranial magnetic stimulation in young adults who meet DSM-5 criteria for cannabis use disorder (CUD). Thirty men (ages 20- 30) who used cannabis daily over the previous 6 months (15 diagnosed of CUD) and 15 demographically matched non-users were enrolled in this study. All participants underwent two sessions of theta burst stimulation (TBS) in which either continuous TBS (cTBS; 600 pulses, 80% active motor threshold) or intermittent TBS (iTBS; 2-s train of cTBS repeated every 10 s for a total of 190 s, 600 pulses) was applied over the primary motor cortex. The effects of these protocols were assessed by analysing the contralateral motor evoked potentials (MEPs). The relationships between cortical plasticity and problematic cannabis use, degree of dependence, and nicotine addiction were also investigated. Significant MEP inhibition after cTBS was observed in both cannabis users without CUD and non-users, while this inhibition was not seen in cannabis users with CUD. Strikingly, less motor cortical plasticity was observed in subjects with severe problematic cannabis use. No significant differences between users and non-users were found in the iTBS-induced cortical plasticity measures. Our study provides the first evidence of maladaptive cortical plasticity associated with cannabis use disorder and problematic cannabis use in humans.

Validation of the French version of the Cannabis Use Disorder Identification Test-Revised and comparison with the Cannabis Abuse Screening Test for screening cannabis use disorder in a psychiatric sample

INTRODUCTION

Several questionnaires have been developed for screening cannabis use disorder in clinical populations, but very few studies have compared the screening abilities of the different instruments. Here, we aimed to confirm the psychometric properties of a French version of the Cannabis Use Disorder Identification Test-Revised (CUDIT-R), and to compare its screening abilities with those of the Cannabis Abuse Screening Test (CAST), in subjects consulting in mental health settings.

METHODS

Two hundred and thirteen cannabis smokers who sought treatment for any type of mental disorder, recruited in four French centres, completed the French CUDIT-R (CUDIT-R-Fr) and the full version of the CAST, and were assessed for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria of cannabis use disorder by an addiction specialist. They were retested with the CUDIT-R-Fr after approximately a week. The factorial construct validity, internal consistency and test-retest reliability of the CUDIT-R-Fr were assessed. The compared sensitivity and specificity of the CAST and CUDIT-R-Fr were explored, using the clinician assessment as the reference.

RESULTS

The French CUDIT-R showed a good internal consistency (Cronbach's alpha = 0.89) and an excellent test-retest reliability (ρ = 0.97). The sensitivity and specificity for screening cannabis use disorder were 0.81 and 0.77 for the CUDIT-R, and 0.92 and 0.63 for the CAST, respectively.

CONCLUSIONS

Based on the recommended cut-offs, the CAST appeared more sensitive, while the CUDIT-R was more specific, for screening cannabis use disorder in a population of cannabis users with heterogeneous types of mental health disorders.

Cannabis use and cannabis use disorder

Cannabis use disorder (CUD) is an underappreciated risk of using cannabis that affects ~10% of the 193 million cannabis users worldwide. The individual and public health burdens are less than those of other forms of drug use, but CUD accounts for a substantial proportion of persons seeking treatment for drug use disorders owing to the high global prevalence of cannabis use. Cognitive behavioural therapy, motivational enhancement therapy and contingency management can substantially reduce cannabis use and cannabis-related problems, but enduring abstinence is not a common outcome. No pharmacotherapies have been approved for cannabis use or CUD, although a number of drug classes (such as cannabinoid agonists) have shown promise and require more rigorous evaluation. Treatment of cannabis use and CUD is often complicated by comorbid mental health and other substance use disorders. The legalization of non-medical cannabis use in some high-income countries may increase the prevalence of CUD by making more potent cannabis products more readily available at a lower price. States that legalize medical and non-medical cannabis use should inform users about the risks of CUD and provide information on how to obtain assistance if they develop cannabis-related mental and/or physical health problems.

Quantity and frequency of cannabis use in relation to cannabis-use disorder and cannabis-related problems

BACKGROUND

In almost all of the literature examining the relation between cannabis use and cannabis-related harms, researchers have neglected to include quantity measures of cannabis use. The study aims to assess whether cannabis: (1) quantity predicts harms; and (2) quantity might interact with other key variables (age, gender, and frequency of use) vis-à-vis the outcomes.

METHOD

Using the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III), the current study (n = 36,309; n = 3,339 past-year cannabis users) employed a logistic-regression approach to assess the cross-sectional relations between the continuous variables of cannabis-use quantity and frequency and two Alcohol Use Disorder and Associated Disabilities Interview Schedule-5 (AUDADIS-5) DSM-5-based outcomes: past-year cannabis-use disorder (CUD) and past-year cannabis-related problems (CRP).

RESULTS

In the CUD model, the key variables log quantity [OR = 1.98 (95 % CI, 1.64;2.39), p < 0.001], log frequency [OR = 1.78 (95 % CI, 1.62;1.96), p < 0.001] and the log-quantity-by-log-frequency interaction [OR = 0.83 (95 % CI, 0.75;0.93), p = 0.002] were statistically significant. The final CRP model included the following main predictors: log quantity [OR = 2.13 (95 % CI, 1.70;2.66), p = <0.001], log frequency [OR = 1.50 (95 % CI, 1.36;1.65), p = <0.001], and a log-quantity-by-log-frequency interaction [OR = 0.82 (95 % CI, 0.73;0.93), p = 0.002].

CONCLUSIONS

The quantity-by-frequency interactions in both models showed that the relative effect of quantity on cannabis-use disorders and cannabis-related problems decreased as frequency increased, and vice versa.

Canadian clinical practice guidelines for the use of plant-based cannabis and cannabinoid-based products in the management of chronic non-cancer pain and co-occurring conditions: protocol for a systematic literature review

INTRODUCTION

Chronic pain and co-occurring disorders, such as sleep disorders, anxiety, depression, post-traumatic stress disorder and substance use disorders, are among the most common conditions for which cannabis and cannabinoid-based products derived from the cannabis plant (CBP) are used for therapeutic purposes. However, healthcare providers report that they lack sufficient information on the risks, benefits and appropriate use of cannabis and CBP derived from the cannabis plant for therapeutic purposes.

METHODS AND ANALYSIS

We will conduct a systematic review of studies investigating the use of cannabis and CBP derived from the cannabis plant for the treatment of chronic pain and co-occurring conditions. Randomised controlled trials, meta-analyses and observational studies will be prioritised. We will exclude reviews of cannabinoid mechanisms of actions, commentary articles and narrative reviews. The primary outcome of interest will be efficacy in relieving chronic pain. Secondary outcomes will be efficacy in ameliorating conditions such as sleep disorders, anxiety, depression, post-traumatic stress disorder and substance use disorders. We will search electronic bibliographic databases including Academic Search Complete, Cochrane Database of Systematic Reviews, Evidence based Medicine Reviewes, OVID Medline, PsychINFO, PubMed, CINAHL and Web of Science. Two reviewers will conduct screening and data collection independently. Study level of bias will be assessed using the Cochrane Risk of Bias Assessment Tool for randomised controlled trials and non-randomised studies. Narrative analysis will be utilised to interpret the data.

ETHICS AND DISSEMINATION

The results of this systematic review will inform guideline development for the use of cannabis and CBP derived from the cannabis plant in the management of chronic pain and co-occurring conditions. Areas requiring further study will also be highlighted.

PROSPERO REGISTRATION NUMBER

CRD42020135886.

Staging and profiling for schizophrenia spectrum disorders: Inter-rater reliability after a short training course

OBJECTIVE

Clinical staging and profiling have been proposed as a new approach in order to refine the diagnostic assessment of schizophrenia spectrum disorders. However, only limited evidence is available for the inter-rater reliability of the clinical staging and profiling model. The aim of the present study was therefore to determine the inter-rater reliability of the clinical staging and profiling model for schizophrenia spectrum disorders, and to investigate whether a short course can improve inter-rater reliability.

METHODS

Consecutively recruited inpatients with schizophrenia spectrum disorders were included between January 2015 and January 2016 (study 1), and between March 2018 and October 2018 (study 2). By contrast with the assessors in study 1, all the assessors in study 2 were trained in clinical staging and profiling. We used the clinical staging model proposed by McGorry and identified profile characteristics. Inter-rater reliability was measured using the Intraclass Correlation Coefficient (ICC).

RESULTS

The ICC score for clinical staging in study 1 was moderate (0.578). It improved considerably in study 2 (0.757). In general, the ICC scores for the profile characteristics in studies 1 and 2 ranged from poor to sufficient (0.123-0.781).

CONCLUSION

This study demonstrated that inter-rater reliability in clinical staging was sufficient after training. However, inter-rater reliability for clinical profile characteristics was highly variable. The general implementation of the clinical staging model for schizophrenia spectrum disorders is therefore feasible but clinical profile characteristics should be used with caution.

HCV-Related Mortality Among HIV/HCV Co-infected Patients: The Importance of Behaviors in the HCV Cure Era (ANRS CO13 HEPAVIH Cohort)

Mortality among individuals co-infected with HIV and hepatitis C virus (HCV) is relatively high. We evaluated the association between psychoactive substance use and both HCV and non-HCV mortality in HIV/HCV co-infected patients in France, using Fine and Gray's competing-risk model adjusted for socio-demographic, clinical predictors and confounding factors, while accounting for competing causes of death. Over a 5-year median follow-up period, 77 deaths occurred among 1028 patients. Regular/daily cannabis use, elevated coffee intake, and not currently smoking were independently associated with reduced HCV-mortality (adjusted sub-hazard ratio [95% CI] 0.28 [0.10-0.83], 0.38 [0.15-0.95], and 0.28 [0.10-0.79], respectively). Obesity and severe thinness were associated with increased HCV-mortality (2.44 [1.00-5.93] and 7.25 [2.22-23.6] versus normal weight, respectively). Regular binge drinking was associated with increased non-HCV-mortality (2.19 [1.10-4.37]). Further research is needed to understand the causal mechanisms involved. People living with HIV/HCV co-infection should be referred for tobacco, alcohol and weight control interventions and potential benefits of cannabis-based therapies investigated.

Heavy cannabis use, dependence and the brain: a clinical perspective

AIMS

To summarize and evaluate our knowledge of the relationship between heavy cannabis use, cannabis use disorder (CUD) and the brain.

METHODS

Narrative review of relevant literature identified through existing systematic reviews, meta-analyses and a PubMed search. Epidemiology, clinical representations, potential causal mechanisms, assessments, treatment and prognosis are discussed.

RESULTS

Although causality is unclear, heavy and dependent cannabis use is consistently associated with a high prevalence of comorbid psychiatric disorders and learning and memory impairments that seem to recover after a period of abstinence. Evidence regarding other cognitive domains and neurological consequences, including cerebrovascular events, is limited and inconsistent. Abstinence after treatment is only achieved in a minority of cases; treatment targeted at reduction in use appears have some success. Potential moderators of the impact of CUD on the brain include age of onset, heaviness of use, CUD severity, the ratio of ∆9-tetrahydrocannabinol to cannabidiol and severity of comorbid disorders.

CONCLUSIONS

Current evidence of long-term effects of daily cannabis use and cannabis use disorder on brain-related outcomes is suggestive rather than conclusive, but use is associated with psychiatric morbidity and with cognitive impairments that recover after a period of abstinence.

Development of a Cannabis Assessment Tool (CAT-1) to measure current and lifetime marijuana use among older Veterans

OBJECTIVE

To develop a tool to assess current (past 30 days) and lifetime marijuana use in older Veterans.

SETTING

US Veteran's Affairs Healthcare System.

PARTICIPANTS

704 older Veterans were screened, 339 completed the initial survey, 100 completed the follow-up.

PRIMARY OUTCOME MEASURE

Pearson's correlation coefficient to assess strength of association between initial and follow-up survey on measures of current and lifetime marijuana use.

RESULTS

Both a 'gram-month' measure of marijuana smoked in the past 30 days (r=0.83) and a frequency-based measure assessing total number of times smoked in the past 30 days were reliable (r=0.89). Both a simple categorical measure of lifetime use (agreement=85%) and a continuous measure of lifetime use (r=0.82) were reliable.

CONCLUSIONS

The Cannabis Assessment Tool offers a reliable assessment of past 30 days and lifetime assessments of smoking cannabis in older adults.

Savoring Moderates the Link between Marijuana Use and Marijuana Problems

Background: The changing legal landscape for marijuana requires concerted efforts toward minimizing the potential harms related to use of the plant. Purpose/Objectives: Identifying buffers against negative consequences in regular users could help researchers fashion prevention efforts that could appeal to those who are uninterested in messages related to abstinence. Savoring, a positively-focused, mindful approach to making the most of positive experiences, appears to overlap with facets of treatment that have proven successful with problem users. The present study examined the role of savoring in the development of marijuana-related problems. Methods: We examined the potential role of savoring as a buffer against marijuana problems in 195 participants (27.3% female). Results: Participants in this sample used cannabis 3.06 days per week on average. Correlations revealed that problems decreased as savoring increased. In addition, a significant interaction revealed that savoring moderated the impact of frequent use on problems. As savoring increased, the positive association between frequency of use and negative consequences decreased, suggesting that those who are high on savoring experience fewer negative consequences than those who are low on savoring even when they use marijuana as frequently. Conclusions: These data support the idea of incorporating savoring into the prevention of marijuana problems.

Differential item functioning analysis of the CUDIT and relations with alcohol and tobacco use among men across five ethnic groups: The HELIUS study

Cannabis use has been rising despite recognition of the negative consequences associated with heavy use. The severity of these consequences has been shown to differ across racial/ethnic groups, even when controlling for consumption levels. The present study conducted an item response theory (IRT) analysis of the Cannabis Use Disorders Identification Test (CUDIT) to better understand the patterns of problematic cannabis use and their relation with other substance use across ethnic groups in the Healthy Life in an Urban Setting (HELIUS) study. CUDIT responses from 1,960 cannabis-using African Surinamese, South-Asian Surinamese, Dutch, Moroccan, and Turkish ethnic origin participants were used to test for differential item functioning (DIF) within an IRT framework. After restricting the sample to men because of low frequency of use among women, several instances of uniform DIF were identified. Multiple-group IRT analysis yielded a harmonized cannabis use phenotype that was used to estimate ethnic group differences in problematic cannabis use and its relation to alcohol and tobacco co-use. These analyses suggested that cannabis users from certain ethnic minority groups experienced higher rates of problematic use than the majority group despite lower rates of cannabis use. Further, cannabis and tobacco use were positively related across groups, whereas only ethnic minority groups showed a positive relation between cannabis and alcohol use. These results demonstrate the importance of accounting for DIF when examining group differences in problematic cannabis use, and support prior evidence suggesting that certain ethnic minority groups may be more likely to experience problematic cannabis use and alcohol co-use relative to the majority group. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Modes of cannabis use: A secondary analysis of an intensive longitudinal natural history study

INTRODUCTION

There is a paucity of research on modes of cannabis use (e.g., joint vs. blunt), and further, little consensus on how to accurately assess both modes of use and route of administration. This secondary analysis used a longitudinal design with data collected daily to characterize mode of cannabis use.

METHODS

193 adult daily cannabis users who were considering quitting at some point enrolled in the study. No treatment was provided. Each day for 84 days, participants reported on mode of cannabis use (i.e., joints, blunts, pipes/vaporizer and food) using an interactive voice response system. We report on single and poly-use of modes across study days and weeks and examine characteristics associated with different modes of use.

RESULTS

White participants were most likely to use pipes/vaporizer, with use on 57% of study days, while Black participants were most likely to use blunts with use on 53% of days. Thus, joint use was less common in both groups. Poly-use of different modes within the same week was very common (i.e., 56% of weeks among White participants and 60% of weeks in Black participants). Age, gender, race, cannabis dependence, presence of others during cannabis use, and alcohol use were associated with different modes of use.

CONCLUSIONS

The major limitation of this study was use of a convenience sample and lack of detailed data on vaporizer use. Joint use is no longer the most common mode of use in either White or Black participants and exclusive use of a single modality is uncommon.

Evaluation of the psychometric properties of the cannabis use disorders identification test - revised among college students

OBJECTIVE

Cannabis use is common among college students and is associated with a variety of negative consequences. The Cannabis Use Disorders Identification Test Revised (CUDIT-R) is an 8-item screening instrument designed to identify potentially problematic or harmful recent cannabis use. The purpose of the current study was to evaluate the internal consistency and validity of the CUDIT-R in a sample of college students who reported recent cannabis use (past 30 day).

METHODS

Participants (n = 229) completed the CUDIT-R and measures of smoking behavior (Daily Smoking Questionnaire; DSQ), cannabis related consequences (Marijuana Problem Index; MPI), and problematic cannabis use (self-reported DSM-5 Cannabis Use Disorder Criteria).

RESULTS

The CUDIT-R showed good internal consistency and concurrent validity with cannabis related outcome measures including; frequency of use, cannabis related consequences, and total DSM-5 criteria endorsed. The CUDIT-R also showed evidence of discriminant validity across DSM-5 severity classifications, achieved high levels of sensitivity (0.929) and specificity (0.704), and excellent area under the receiver operating characteristics curve when using a cutoff score of six. All items displayed high levels of discrimination and varied in terms of difficulty and information provided.

CONCLUSIONS

Overall, the CUDIT-R appears to be a reliable and valid screening measure when used to identify college students at risk for cannabis related problems. Future research should further evaluate the sensitivity and specificity of the CUDIT-R threshold scores with more rigorously established DSM-5 diagnoses, and across a range of populations. Research on the utility of using the CUDIT-R for measuring treatment outcomes is also warranted.

Concurrent and Simultaneous Use of Cannabis and Tobacco and Its Relationship with Academic Achievement amongst University Students

The combined use of cannabis and tobacco is frequent in Europe. Few studies have nonetheless explored this pattern of consumption and its relationship with academic achievement in Spanish population. The aim of the present study was to analyze (1) the frequency of four patterns of polydrug use the last year (non-dual users of cannabis and tobacco; concurrent users: cannabis and tobacco separately; simultaneous users: tobacco in cannabis "joints"; simultaneous users: tobacco in cannabis joints alongside alcohol) by gender and age; (2) grade point average (GPA) by gender and age; (3) the association between the frequency of the four patterns of use and the GPA amongst a sample of 477 Spanish university students. The use of cannabis and tobacco (concurrent and simultaneous) and GPA were assessed by means of self-reported questionnaires. Statistically significant differences were found for the GPA with respect to gender. The GPA by the non-dual users of cannabis and tobacco was significantly higher than the GPA corresponding to the concurrent and simultaneous users. The combined use of cannabis and tobacco, regardless of the type of use (concurrent or simultaneous), is moderately related to poor academic achievement amongst university students.

Prevalence of problematic cannabis use in Canada: Cross-sectional findings from the 2013 Canadian Tobacco, Alcohol and Drugs Survey

OBJECTIVES

Cannabis is the most widely used illicit substance in Canada. There exist a variety of tools to measure problematic characteristics of cannabis use; however, there is no consensus on the operational definition of "problematic use". The current study sought to estimate the prevalence of problematic cannabis use in Canada, in terms of the kinds of problems Canadians report due to their cannabis use, the levels of harm associated with cannabis consumption, and potential differences among socio-demographic groups.

METHODS

Cross-sectional, nationally representative data for Canadians were obtained from the publicly available Statistics Canada's 2013 Canadian Tobacco, Alcohol and Drugs Survey (CTADS) (n = 13 635). Binary logistic regression analyses were conducted to examine subgroup differences in patterns of cannabis use and problematic outcomes defined by the World Health Organization's Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) tool embedded in CTADS.

RESULTS

The findings indicate that, while 1 in 10 Canadians reported using cannabis in the past 3 months, only 2% of the sample of Canadians who reported using cannabis in the past 3 months were characterized as having a "high risk" of severe health or other problems. Canadian male respondents were more likely to report social problems than females and to be categorized as high risk. Youth and young adults between the ages of 15 and 29 consistently reported a greater prevalence of problems associated with their cannabis consumption than their older counterparts.

CONCLUSION

A very small proportion of Canadians report using cannabis to a degree that is problematic. Approximately one in two young people reported using cannabis at some point in their lives, of concern given the negative health outcomes of early cannabis use. This study highlights the need for the development of more sensitive instruments to detect problematic cannabis use.

Measuring cannabis consumption: Psychometric properties of the Daily Sessions, Frequency, Age of Onset, and Quantity of Cannabis Use Inventory (DFAQ-CU)

Objective

We created the Daily Sessions, Frequency, Age of Onset, and Quantity of Cannabis Use Inventory (DFAQ-CU) because the current lack of psychometrically sound inventories for measuring these dimensions of cannabis use has impeded research on the effects of cannabis in humans.

Method

A sample of 2,062 cannabis users completed the DFAQ-CU and was used to assess the DFAQ-CU’s factor structure and reliability. To assess validity, a subsample of 645 participants completed additional measures of cannabis dependence and problems (Marijuana Smoking History Questionnaire [MSHQ], Timeline Followback [TLFB], Cannabis Abuse Screening Test [CAST], Cannabis Use Disorders Identification Test Revised [CUDIT-R], Cannabis Use Problems Identification Test [CUPIT], and Alcohol Use Disorder Identification Test [AUDIT]).

Results

A six-factor structure was revealed, with factors measuring: daily sessions, frequency, age of onset, marijuana quantity, cannabis concentrate quantity, and edibles quantity. The factors were reliable, with Cronbach’s alpha coefficients ranging from .69 (daily sessions) to .95 (frequency). Results further provided evidence for the factors’ convergent (MSHQ, TLFB), predictive (CAST, CUDIT-R, CUPIT), and discriminant validity (AUDIT).

Conclusions

The DFAQ-CU is the first psychometrically sound inventory for measuring frequency, age of onset, and quantity of cannabis use. It contains pictures of marijuana to facilitate the measurement of quantity of marijuana used, as well as questions to assess the use of different forms of cannabis (e.g., concentrates, edibles), methods of administering cannabis (e.g., joints, hand pipes, vaporizers), and typical THC levels. As such, the DFAQ-CU should help facilitate research on frequency, quantity, and age of onset of cannabis use.

Microaggressions and marijuana use among college students

This study examines the association between exposure to microaggressions and marijuana use, using original survey data from a sample of racial/ethnic minority college students (n = 332) from a large Division I university in the United States. Nearly all of our sample (96%) reported at least one experience with microaggressions in the past 6 months, while 33% reported using marijuana regularly. We modeled regular use of marijuana using multiple logistic regression, with consideration of sex, age, race/ethnicity, and microaggression scale scores as covariates. Age, sex, the microinvalidations subscale score, and the full microaggression scale score were significantly associated with marijuana use in our full models (p < .01; p = .01; p = .02; p = .03, respectively). With each additional experience of microaggression, the odds of regular marijuana use increase. Academic communities may consider the primary prevention of discriminatory behavior when addressing student substance use.

Definitions of Risky and Problematic Cannabis Use: A Systematic Review

Although cannabis is widely used, it remains unclear which consumption patterns are more likely to produce future consequences (risky/hazardous use) or current damage (problematic/harmful use). This unresolved issue contributes to cannabis public health implications. In order to facilitate further consensus, this review analyzes previously used definitions in the literature.

METHODS

This systematic review was performed following the PRISMA guidelines. Articles published before October 2015 in the Medline, Scopus-Elsevier, ISI-Web of Knowledge and Cochrane databases and fulfilling a-priori decided criteria were retrieved. Definitions in preselected websites of national and international organizations addressing drug problems were also included.

RESULTS

Definitions identified in articles (n = 46) and official websites (n = 3) widely varied from each other. Weekly cannabis use was mostly considered risky. Problematic cannabis use was mostly described with the Cannabis Abuse and Screening Test. Evidence-based definitions as well as information on quantities consumed, time-frames and special considerations for risky groups were very limited.

CONCLUSIONS

Working on official definitions is highly necessary as criteria used remain incomplete, leading to increased confusion in the field. Recommendations to improve existing definitions are given.

Progesterone and Postpartum Smoking Relapse: A Pilot Double-Blind Placebo-Controlled Randomized Trial

INTRODUCTION

Pregnancy is a strong motivator to quit smoking, yet postpartum relapse rates are high. Growing evidence suggests a role of sex hormones in drug abuse behavior and given the precipitous drop in sex hormones at delivery, they may play a role in postpartum relapse. This pilot study evaluates the feasibility and potential role of exogenous progesterone in postpartum smoking relapse.

METHODS

This 12-week double-blind placebo-controlled randomized pilot trial randomized 46 abstinent postpartum women to active progesterone (PRO; 200mg twice a day) versus placebo (PBO) for 4 weeks. Participants were followed for relapse for 12 weeks. Main study outcomes include abstinence (point prevalence), feasibility (compliance per number of clinic visits attended, pill counts and Electronic Data Capture [EDC] completed) and self-reported acceptability. Safety was also measured by depressive symptom scores, adverse events, and breastfeeding.

RESULTS

Overall retention rate was 87% at week 12. At week 4, abstinence rates were 75% in the PRO group and 68.2% in the PBO group (p = .75). Medication adherence was 68% and clinic visit attendance was 80%, with no differences by randomization. Depressive symptom scores, adverse events, and breastfeeding did not vary by randomization.

CONCLUSIONS

Although the study was not powered to evaluate abstinence rates, we did observe a higher prevalence of abstinence at week 4 in the PRO group. Further, exogenous progesterone was well tolerated and did not adversely affect depressive symptoms or breastfeeding. Thus, the results of this pilot study indicate further investigation into progesterone as a postpartum relapse prevention strategy is warranted.

IMPLICATIONS

This innovative pilot trial determined the feasibility of delivering exogenous progesterone as a potential prevention of postpartum smoking relapse. We observed high retention and moderate adherence rates, as well as high acceptability among participants. Further, though not statistically significant, more women in the treatment group remained abstinent from smoking during follow-up. This project adds to the growing body of literature on the role of sex hormones in smoking relapse and also provides support for a fully powered clinical trial.

Clearing the haze: the complexities and challenges of research on state marijuana laws

As states increasingly liberalize marijuana laws, high-quality research is needed that will inform the public and policymakers about the health and societal impact of these laws. However, there are many challenges to studying marijuana policy, including the heterogeneity of the drug and its use, the variability in the laws and their implementation from state to state, the need to capture a wide variety of relevant outcomes, and the poorly understood influence of marijuana commercialization. Furthermore, current instruments generally fail to distinguish between types of users and lack accurate and detailed measures of use. This review provides a background on marijuana laws in the United States and an overview of existing policy research, discusses methodological considerations when planning analysis of state marijuana laws, and highlights specific topics needing further development and investigation.

Safety and Toxicology of Cannabinoids

There is extensive research on the safety, toxicology, potency, and therapeutic potential of cannabis. However, uncertainty remains facilitating continued debate on medical and recreational cannabis policies at the state and federal levels. This review will include a brief description of cannabinoids and the endocannabinoid system; a summary of the acute and long-term effects of cannabis; and a discussion of the therapeutic potential of cannabis. The conclusions about safety and efficacy will then be compared with the current social and political climate to suggest future policy directions and general guidelines.