A Survey of Cannabis Acute Effects and Withdrawal Symptoms: Differential Responses Across User Types and Age

Contextual factors associated with subjective effects of cannabis: A systematic review and meta-analysis

BACKGROUND

Cannabis is consumed in various social and environmental settings, and such contexts may be important predictors of subjective effects. The aim of this systematic review and meta-analysis was to examine the relationship between contextual factors and subjective effects of cannabis.

METHODS

A PRISMA-guided search of MEDLINE, Embase, PsycINFO, Global Health, and Google Scholar yielded 29 studies.

RESULTS

Study type (Ecological Momentary Assessment or Experimental) was a significant predictor of intoxication effects, and experimental studies had a greater pooled effect size (z =.296,95 % CI [.132,.478], p=.004) than Ecological Momentary Assessment (EMA) studies (z =.071,95 % CI [.011,.130], p =.02). Contextual conditions (environment, social group, expectancy, time of day, day of week) were not significant predictors of cannabis effects.

CONCLUSION

Findings did not point to a significant association between contextual conditions and subjective effects. However, as current literature is methodologically weak, it may be premature to conclude that subjective effects are not shaped by contextual factors. In view of policy and therapeutic implications, replications and study refinements are recommended.

Assessing rates and predictors of cannabis-associated psychotic symptoms across observational, experimental and medical research

Cannabis, one of the most widely used psychoactive substances worldwide, can give rise to acute cannabis-associated psychotic symptoms (CAPS). While distinct study designs have been used to examine CAPS, an overarching synthesis of the existing findings has not yet been carried forward. To that end, we quantitatively pooled the evidence on rates and predictors of CAPS (k = 162 studies, n = 210,283 cannabis-exposed individuals) as studied in (1) observational research, (2) experimental tetrahydrocannabinol (THC) studies, and (3) medicinal cannabis research. We found that rates of CAPS varied substantially across the study designs, given the high rates reported by observational and experimental research (19% and 21%, respectively) but not medicinal cannabis studies (2%). CAPS was predicted by THC administration (for example, single dose, Cohen's d = 0.7), mental health liabilities (for example, bipolar disorder, d = 0.8), dopamine activity (d = 0.4), younger age (d = -0.2), and female gender (d = -0.09). Neither candidate genes (for example, COMT, AKT1) nor other demographic variables (for example, education) predicted CAPS in meta-analytical models. The results reinforce the need to more closely monitor adverse cannabis-related outcomes in vulnerable individuals as these individuals may benefit most from harm-reduction efforts.

Factors associated with the use of cannabis for self-medication by adults: data from the French TEMPO cohort study

BACKGROUND

Medical cannabis, legalized in many countries, remains illegal in France. Despite an experiment in the medical use of cannabis that began in March 2021 in France, little is known about the factors associated with the use of cannabis for self-medication among adults.

METHODS

Data came from the French TEMPO cohort and were collected between December 2020 and May 2021. Overall, 345 participants aged 27-47 were included. Cannabis for self-medication was defined using the following questions: 'Why do you use cannabis?' and 'In what form do you use cannabis?'. The penalized regression method "Elastic net" was used to determine factors associated with the use of cannabis for self-medication, with the hypothesis that it is mainly used for pain in individuals who have already used cannabis.

RESULTS

More than half of the participants reported having ever used cannabis (58%). Only 10% used it for self-declared medical reasons (n = 36). All self-medication cannabis users, except one, were also using cannabis for recreational purposes. The main factors associated with cannabis use for self-medication vs. other reasons included cannabis use trajectories, the presence of musculoskeletal disorders, tobacco smoking, and parental divorce.

CONCLUSIONS

Engaging in cannabis use during adolescence or early adulthood may increase the likelihood of resorting to self-medication in adulthood. Due to the propensity of individuals with cannabis use during adolescence to resort to uncontrolled products for self-medication, this population should be more systematically targeted and screened for symptoms and comorbidities that may be associated with cannabis use.

Adverse outcomes of cannabis use in Canada, before and after legalisation of non-medical cannabis: cross-sectional analysis of the International Cannabis Policy Study

OBJECTIVES

To date, there is little evidence on the extent to which cannabis legalisation affects the prevalence of adverse events from cannabis at the population level. The current study examined trends in the prevalence of adverse events among people who consumed cannabis before and after Canada's legalisation of recreational cannabis.

DESIGN

Data come from the first four survey waves of the International Cannabis Policy Study, which were conducted online annually immediately prior to non-medical cannabis legalisation in Canada in October 2018, and in the three following years (2019-2021).

PARTICIPANTS

The current analysis included 18 285 Canadian respondents aged 16-65 who reported cannabis use in the past 12 months.

OUTCOME MEASURES

Primary outcomes included types of adverse events experienced from cannabis use, medical help-seeking and the types of products used. Weighted logistic regression models examined differences in help-seeking, emergency room usage and the experience of cannabinoid hyperemesis syndrome across survey years.

RESULTS

Approximately one-third of people who consume cannabis reported experiencing at least one adverse event within the past 12 months, including 5% of consumers who sought medical help for an adverse event, most commonly for panic attacks, feeling faint/dizzy/passing out, heart/blood pressure problems and nausea/vomiting. The prevalence of seeking help and the types of adverse events were similar before (2018) and after legalisation (2019-2021); however, the proportion of consumers seeking help from emergency rooms increased postlegalisation (F=2.77, p=0.041). Adverse events were associated with various product types, with dried flower and oral oils accounting for the largest proportion of events. Help-seeking associated with cannabis edibles significantly decreased after legalisation (p=0.001).

CONCLUSIONS

Substantial proportions of people who consume cannabis report adverse events, suggesting widespread difficulty in 'dosing'. Few changes were observed in the prevalence of adverse events reported by consumers since legalisation; however, the location of medical help-seeking and associated products used have changed postlegalisation.

A longitudinal study of cannabis use and risk for cognitive and functional decline among older adults with HIV

Cannabis use is rapidly increasing among older adults in the United States, in part to treat symptoms of common health conditions (e.g., chronic pain, sleep problems). Longitudinal studies of cannabis use and cognitive decline in aging populations living with chronic disease are lacking. We examined different levels of cannabis use and cognitive and everyday function over time among 297 older adults with HIV (ages 50-84 at baseline). Participants were classified based on average cannabis use: frequent (> weekly) (n = 23), occasional (≤ weekly) (n = 83), and non-cannabis users (n=191) and were followed longitudinally for up to 10 years (average years of follow-up = 3.9). Multi-level models examined the effects of average and recent cannabis use on global cognition, global cognitive decline, and functional independence. Occasional cannabis users showed better global cognitive performance overall compared to non-cannabis users. Rates of cognitive decline and functional problems did not vary by average cannabis use. Recent cannabis use was linked to worse cognition at study visits when participants had THC+ urine toxicology-this short-term decrement in cognition was driven by worse memory and did not extend to reports of functional declines. Occasional (≤ weekly) cannabis use was associated with better global cognition over time in older adults with HIV, a group vulnerable to chronic inflammation and cognitive impairment. Recent THC exposure may have a temporary adverse impact on memory. To inform safe and efficacious medical cannabis use, the effects of specific cannabinoid doses on cognition and biological mechanisms must be investigated in older adults.

Cannabis use for Sleep Disturbance Among Older Patients in a Geriatrics Clinic

Cannabis use is growing among older adults to manage medical concerns including poor sleep. In this study, we characterized how patients seen at a geriatrics clinic use cannabis to address sleep disturbance. Specifically, we conducted an anonymous survey of 568 adults, including 83 who reported cannabis use within the past 3 years, to inquire about such use. We compared cannabis use characteristics between those using it for sleep disturbance versus all other conditions. We considered a p-value <.10 to be statistically significant. Among the cannabis users in our sample, 29% reported using cannabis for sleep disturbance (N = 24). They were more likely than other users to be female (p = .07), consume cannabis more frequently (p = .01), use products containing tetrahydrocannabinol (THC) (vs. cannabidiol [CBD]-only; p < .01), and use cannabis to target more symptoms (p < .01). As cannabis use continues to grow in older populations, it is essential to delineate better how cannabis may be used safely and effectively to improve older adults' sleep health.

E-cigarette, cannabis and combustible tobacco use: associations with xerostomia among California adolescents

OBJECTIVE

Xerostomia (subjective experience of dry mouth), while less common in younger populations, can contribute to caries and oral discomfort. Use of e-cigarettes and cannabis among adolescents is increasing and may be a xerostomia risk factor. This study evaluates xerostomia prevalence in an adolescent population, overall and by e-cigarette, cannabis and combustible tobacco use.

METHODS

Cross-sectional analyses of 12-month follow-up data (N=976; collected 2020-2021) from a cohort of adolescents recruited from public high schools in Northern California (USA) compared self-reported past 30-day e-cigarette, cannabis and other tobacco use and dry mouth (overall dry mouth experience; shortened xerostomia inventory, SXI). Dry mouth experience (never, occasionally, frequently/always) was modelled using ordered logistic regression with school-level clustering and adjustment for gender, race/ethnicity, alcohol use, asthma, physical activity and mutually for e-cigarette, cannabis and tobacco use.

RESULTS

Past 30-day use prevalence was 12% for e-cigarettes, 16% for cannabis and 3% for combustible tobacco. Occasional dry mouth experience (54%) was more common than frequent/always experience (5%). Frequent/always dry mouth was more prevalent among frequent (>5 days/month) e-cigarette (14%) and cannabis (19%) users and combustible tobacco users (19%) than non-users of those respective products (all comparisons p < 0.001). In covariable-adjusted models, frequent e-cigarette use was no longer significantly associated with dry mouth experience (OR: 1.40; 95% CI: 0.69, 2.84), while frequent cannabis use (OR: 3.17; 95% CI: 1.47, 6.82) and combustible tobacco use (OR: 1.92; 95% CI: 1.38, 2.68) were associated with greater odds of reporting more frequent dry mouth. Findings were qualitatively similar using the SXI.

CONCLUSIONS

In this study, xerostomia was not independently associated with e-cigarette use but was one potential health concern of adolescent cannabis and combustible tobacco use.

Recommendation for Cannabis Use Disorder Diagnosis in a Context of Cannabis for Therapeutic Purposes

This Viewpoint proposes a model of cannabis use disorder diagnosis in the context of cannabis for therapeutic purposes that is based on DSM-5 model of diagnosing substance use disorder in the context of prescribed medication use

Experience of Cannabis Use from Adolescence to Adulthood in France: An Interpretative Phenomenological Analysis

Levels of cannabis use are high during adolescence, but the proportion of cannabis users among adults is also progressing, often for medical reasons. This study describes the reasons and motivations for using medical cannabis among adults over 30 years old in France. This qualitative study was performed using an interpretative phenomenological analysis. People with a history of cannabis use or current cannabis users were recruited from the TEMPO cohort. Homogeneous purposive sampling was applied among those using medical cannabis. Twelve participants, among thirty-six who reported using cannabis for medical reasons, were selected and interviewed. Five superordinate themes were identified in the analysis: 1-soothing a traumatic experience through cannabis use; 2-an ambivalent relationship with the user and cannabis and with the user and close relatives; 3-cannabis, a known soft drug comparable to alcohol or tobacco, leading to an illogical demonization; 4-recreational use in the context of experimentation; and 5-a paradoxical desire for exemplary parenting. In this first recent study to describe the reasons and views adults have in order to continue using cannabis after 30 years of age, we identified ways to explain this consumption. The internal appeasement provoked by cannabis stems from a struggle to appease a violent external situation.

Effects of inhaled cannabis high in Δ9-THC or CBD on the aging brain: A translational MRI and behavioral study

With the recent legalization of inhaled cannabis for medicinal and recreational use, the elderly represents one of the newest, rapidly growing cohorts of cannabis users. To understand the neurobiological effects of cannabis on the aging brain, 19-20 months old mice were divided into three groups exposed to vaporized cannabis containing ~10% Δ9-THC, ~10% CBD, or placebo for 30 min each day. Voxel based morphometry, diffusion weighted imaging, and resting state functional connectivity data were gathered after 28 days of exposure and following a two-week washout period. Tail-flick, open field, and novel object preference tests were conducted to explore analgesic, anxiolytic, and cognitive effects of cannabis, respectively. Vaporized cannabis high in Δ9-THC and CBD achieved blood levels reported in human users. Mice showed antinociceptive effects to chronic Δ9-THC without tolerance while the anxiolytic and cognitive effects of Δ9-THC waned with treatment. CBD had no effect on any of the behavioral measures. Voxel based morphometry showed a decrease in midbrain dopaminergic volume to chronic Δ9-THC followed but an increase after a two-week washout. Fractional anisotropy values were reduced in the same area by chronic Δ9-THC, suggesting a reduction in gray matter volume. Cannabis high in CBD but not THC increased network strength and efficiency, an effect that persisted after washout. These data would indicate chronic use of inhaled cannabis high in Δ9-THC can be an effective analgesic but not for treatment of anxiety or cognitive decline. The dopaminergic midbrain system was sensitive to chronic Δ9-THC but not CBD showing robust plasticity in volume and water diffusivity prior to and following drug cessation an effect possibly related to the abuse liability of Δ9-THC. Chronic inhaled CBD resulted in enhanced global network connectivity that persisted after drug cessation. The behavioral consequences of this sustained change in brain connectivity remain to be determined.

Recreational cannabis use is associated with poorer sleep outcomes in young adult African Americans

INTRODUCTION

The present study sought to determine the relationship between self-reported cannabis use dosage in grams per day with (1) objective sleep outcomes: sleep efficiency (SE), sleep onset latency SOL and number of night-time awakenings (NWAK) (2) if objective and subjective sleep measures, using the PSQI, differed between cannabis users and non-cannabis users.

METHODS

Our sample included 178 participants, aged 18-35 years. We collected demographic information, cannabis use in dosage per day and frequency of use, depressive symptoms through the CESD, and subjective sleep reports using the PSQI. After the survey assessment, we monitored sleep using the Phillips Actiwatch Spectrum watch for a minimum of 5 nights.

RESULTS

The amount of cannabis consumed per day was inversely related to SOL and SE, and positively related to NWAK. After controlling for covariates, regression models were statistically significant for predicting SOL (β = -0.369, p <.001), SE (β = -0.232, p <.05) and NWAK, (β = -0.318, p <.001), indicating cannabis dosage per day is the strongest predictor for the sleep parameters. Subjective sleep measures did not differ from cannabis users versus non-cannabis users.

CONCLUSION

Recreational cannabis use is beneficial for SOL but may be detrimental to SE as those who reported increased cannabis use also had more NWAK. Cannabis may be useful for sleep onset, results suggest that increased use does not aid in sleep maintenance.

Rates and correlates of cannabis-associated psychotic symptoms in over 230,000 people who use cannabis

Cannabis, a widely used psychoactive substance, can trigger acute cannabis-associated psychotic symptoms (CAPS) in people who use cannabis (PWUC). To assess rates and correlates of CAPS requiring emergency medical treatment, we analyzed data from an international sample of PWUC (n = 233,475). We found that 0.47% (95%CI 0.42; 0.52) PWUC reported lifetime occurrence of CAPS, defined as the occurrence of hallucinations and/or paranoia requiring emergency medical treatment following the use of cannabis. A range of factors correlated with risk of CAPS in the last year: higher rates were observed in young individuals [risk ratio (RR) 2.66, compared to older PWUC] and those residing in Denmark (RR 3.01, compared to PWUC from other countries). Furthermore, risk was elevated in those using predominantly high-potency resin (RR 2.11, compared to PWUC using herbal cannabis), those mixing cannabis with tobacco (RR 2.15, compared to PWUC not mixing with tobacco) and those with a diagnosis of psychosis (RR 14.01), bipolar (RR 4.30), anxiety (RR 2.92) and depression (RR 2.68), compared to individuals without a mental health diagnosis. Taken together, acute self-limiting psychotic symptoms in the context of cannabis use may occur in about 1 in 200 PWUC's lifetime. Some individuals could be particularly sensitive to the adverse psychological effects of cannabis, such as young individuals or those with pre-existing mental health vulnerabilities. In light of the movements towards legalization of recreational cannabis, more research should focus on the potential harms related to cannabis use, to educate PWUC and the public about risks related to its use.

Physician Communication and Perceived Stigma in Prenatal Cannabis Use

Cannabis has long been widely used throughout the prenatal period. However, motives for prenatal cannabis use (PCU) have not been comprehensively examined. Stigmatization has been identified as a barrier to therapeutic cannabis use and related physician communication. Such stigma may be particularly salient in the context of PCU. One hundred and three women who reported current or past pregnancy were recruited online. Participants completed a survey querying prenatal experiences, substance use, and attitudes toward PCU. PCU was reported by 35 (34%) respondents. Treating nausea and vomiting of pregnancy was the most frequently reported reason for PCU (89%), and 24 (69%) reported substituting cannabis for pharmaceutical drugs. Sixty-two percent of PCU participants and 31% of non-PCU participants indicated discomfort discussing PCU with their physician, and 74% of PCU participants and 27% of non-PCU participants indicated they would not disclose PCU to their physician if it occurred in future pregnancies. Our findings suggest that PCU may reflect primarily therapeutic motives of relieving symptoms of morning sickness, nausea, low appetite, pain, and substituting for other prescription medications. Respondents reported discomfort discussing PCU with physicians, which was more pronounced among respondents with lived experience of PCU. Findings suggest PCU might best be evaluated within a therapeutic framework and highlight the importance of efforts to enhance patient-caregiver communication regarding PCU.

Differences in clinical features associated with cannabis intoxication in presentations to European emergency departments according to patient age and sex

OBJECTIVE

To investigate if clinical features associated with acute cannabis intoxication in patients presenting to Emergency Departments for medical assistance differ according to patient age and sex.

METHODS

We analysed presentations in the Euro-DEN Plus dataset from 2014 to 2019 in which cannabis was the only drug involved (except for alcohol), and age, sex and alcohol co-ingestion had been recorded. Age was considered as categorical (five groups; <20, 20-29, 30-39, 40-49 and ≥50 years), and sex as binary variable (male/female). We evaluated 12 key clinical features recorded during emergency department (ED) care. Risks of presenting with each of these clinical features according to patient age and sex were calculated by logistic regression models, and adjusted for sex, age and alcohol co-ingestion.

RESULTS

4,268 of 43,633 Euro-DEN presentations (9.8%) fulfilled the inclusion criteria (median age: 26 years (IQR = 20-34), 70% male, 52% co-ingested alcohol). The frequency of clinical features was: anxiety 28%, vomiting 24%, agitation 23%, palpitations 14%, reduced consciousness 13%, acute psychosis 9%, hallucinations 9%, chest pain 7%, headache 6%, hypotension 4%, hypertension 3% and seizures 2%. Patients younger than 20 years more frequently had vomiting (34.7% of cases), reduced consciousness (21.5%), and headache (10.8%); and less frequently acute psychosis (5.5%). Patients older than 49 years more often had hypotension (6.5%) and less frequently vomiting (20%), anxiety (14%), agitation (14%) and reduced consciousness (10%). Males more frequently presented with hypertension (3.7 vs. 1.5%; OR = 2.311, 95%CI = 1.299-3.816), psychosis (10.4 vs 6.3%; 1.948, 1.432-2.430), chest pain (8.1 vs 4.5%; 1.838, 1.390-2.430) and seizures (2.5 vs 1.4%; 1.805, 1.065-3.060), and less frequently with vomiting (21.8 vs 28.2%; 0.793, 0.677-0.930), anxiety (25.4 vs 32.3%; 0.655, 0.561-0.766) and hypotension (2.9 vs 5.8%; 0.485, 0.350-0.671).

CONCLUSIONS

The prevalence of some clinical features typically associated with acute cannabis intoxication differed according to age and sex. The causes for these differences should be further investigated in order to better understand the pathophysiology of cannabis-related acute toxicity, and they may be relevant particularly for developing prevention campaigns and for treatment in specific sex and/or age groups.

Dos(e)Age: Role of Dose and Age in the Long-Term Effect of Cannabinoids on Cognition

Cannabis is still the most widely used illicit drug around the world. While its use has always been prevalent among adolescents, recent evidence suggests that its consumption is also increasing among other population groups, such as pregnant women and aged people. Given the known impact of cannabis on brain development and behavior, it is important to dissect the possible long-term impact of its use across different age groups, especially on measures of cognitive performance. Animal models of cannabinoid exposure have represented a fundamental tool to characterize the long-lasting consequences of cannabinoids on cognitive performance and helped to identify possible factors that could modulate cannabinoids effects in the long term, such as the age of exposure and doses administered. This scoping review was systematically conducted using PubMed and includes papers published from 2015 to December 2021 that examined the effects of cannabinoids, either natural or synthetic, on cognitive performance in animal models where exposure occurred in the prenatal period, during adolescence, or in older animals. Overall, available data clearly point to a crucial role of age in determining the long-term effect of cannabinoid on cognition, highlighting possible detrimental consequences during brain development (prenatal and adolescent exposure) and beneficial outcomes in old age. In contrast, despite the recent advances in the field, it appears difficult to clearly establish a possible role of dosage in the effects of cannabinoids on cognition, especially when the adolescent period is taken into account.

Predicting Self-Medication with Cannabis in Young Adults with Hazardous Cannabis Use

Using cannabis to reduce psychological and physical distress, referred to as self-medication, is a significant risk factor for cannabis use disorder. To better understand this high-risk behavior, a sample of 290 young adults (ages 18–25; 45.6% female) were recruited from two U.S. universities in January and February of 2020 to complete a survey about their cannabis use and self-medication. Results: seventy-six percent endorsed using cannabis to reduce problems such as anxiety, sleep, depression, pain, loneliness, social discomfort, and concentration. When predicting reasons for self-medication with cannabis, logistic regression models showed that lower CUDIT-R scores, experiencing withdrawal, living in a state where cannabis was illegal, and being female were all associated with higher rates of self-medication. Withdrawal symptoms were tested to predict self-medication with cannabis, and only insomnia and loss of appetite were significant predictors. To further explore why young adults self-medicate, each of the original predictors were regressed on seven specified reasons for self-medication. Young adults experiencing withdrawal were more likely to self-medicate for pain. Participants living where cannabis is legal were less likely to self-medicate for anxiety and depression. Living where cannabis is illegal also significantly predicted self-medicating for social discomfort—though the overall model predicting social discomfort was statistically non-significant. Finally, female participants were more likely to self-medicate for anxiety. These results suggest widespread self-medication among young adults with likely CUD and underscore the complexity of their cannabis use. The findings have implications for understanding why young adults use cannabis in relation to psychological and physical distress and for accurately treating young adults with cannabis use disorder.

Age-related changes in CB1 receptor expression and function and the behavioral effects of cannabinoid receptor ligands

Cannabinoid use has increased among aging individuals. However, little information on age-related differences in the behavioral effects of these agents is available. To explore potential differences in the behavioral effects of cannabinoids, we determined effects of Δ⁹-tetrahydrocannabinol (THC, 1-10 mg/kg) or rimonabant (0.3-3.2 mg/kg) on operant fixed-ratio responding (FR10) for food in young adult (6 months) and aged (29 months) rats. THC dose-dependently decreased responding for food. Rimonabant alone had little or no effect on responding up to 1.0 mg/kg, but disrupted responding following a 3.2 mg/kg dose. Rimonabant (1.0 mg/kg) partially antagonized response disruption by THC. These effects were similar in young adult and aged rats. However, aging has been reported to change the neurobiology of cannabinoid CB1 receptors. To confirm our rats exhibited such differences, we assessed CB1 receptor binding sites and function in six subcortical (caudate, nucleus accumbens CA1, and CA2/CA3), and three cortical regions (medial prefrontal, temporal, entorhinal) in young adult (6 months) or aged (26 months) male Lewis rats using quantitative autoradiography. CB1 receptor binding sites were reduced in cortical, but not subcortical brain regions of aged rats. CB1 receptor function, at the level of receptor-G protein interaction, was not different in any region studied. Results indicate that down-regulation of CB1 receptor binding sites observed in cortical regions of aged rats was not accompanied by a commensurate decrease in CB1 receptor-stimulated [³⁵S]GTPγS binding, suggesting a compensatory increase in receptor function in cortical areas. Together, our results provide additional evidence of age-related changes in central CB1 receptor populations. However, the functional compensation for decreased CB1 receptor binding may mitigate changes in behavioral effects of cannabinoids. With the rising use of cannabinoid-based therapeutics among aging populations, further evaluation of age-related changes in the cannabinoid system and the impact of these changes on effects of this class of drugs is warranted.

Cannabis for the Treatment of Attention Deficit Hyperactivity Disorder: A Report of 3 Cases

Attention deficit hyperactivity disorder (ADHD) is a chronic neurobehavioral disorder that is highly prevalent in children and adults. An increasing number of patients with ADHD are self-medicating with cannabis, despite a lack of evidence on efficacy and safety. This case report describes 3 males (ages 18, 22, and 23) who have integrated cannabis into their treatment regimen with positive results. Semistructured interviews conducted with the patients describe subjective improvements in symptoms and on quality of life. Improvements on validated rating scales conducted post-cannabis initiation, compared to pre-cannabis initiation obtained from the medical chart, corroborated their personal accounts. Scores on the PHQ-9 (measuring depression) improved by 8-22 points (30-81%), and the SCARED (measuring anxiety) ranged from 0 to 27 points (up to 33%). Improvements on the CEER-9 scale (measuring regulation) ranged from 2 to 7 points (22-78%), and the 9-item SNAP scale (measuring inattention) showed improvements of 2-8 points (7-30%). Mild adverse events including short-term memory problems, dry mouth, and sleepiness were reported. Blood samples were also collected from the patients to determine the plasma concentrations of the cannabinoids and relevant metabolites before and after a cannabis administration. After cannabis use, the plasma levels for CBD and THC ranged from 0 to 15.29 ng/mL and 1.32 to 13.76 ng/mL, respectively. Cannabinoids, however, were not detected prior to dosing, suggesting that cannabis played a complimentary role in the therapeutic regimen of these 3 patients. Clinical trials are recommended to confirm the efficacy of cannabis in the treatment of ADHD.

Pharmacokinetics and Perceptions of Children and Young Adults Using Cannabis for Attention-Deficit/Hyperactivity Disorder and Oppositional Defiant Disorder: Protocol for a Mixed Methods Proof-of-Concept Study

Background

Despite the lack of evidence on the use of cannabis for the treatment of attention-deficit/hyperactivity disorder (ADHD), the growing perception that cannabis is safe has led more patients and caregivers to self-medicate. Some psychiatrists now authorize medicinal cannabis for patients with ADHD with features of oppositional defiant disorder (ODD) to curtail the unregulated (ie, self-medicated) use of recreational cannabis or to offer a therapeutic option to those who continue to experience symptoms after exhausting all other treatment options.

Objective

This protocol aims to explore the perceived effectiveness and pharmacokinetics of cannabis in youth and young adults, who are currently taking it as part of their treatment plan for ADHD with features of ODD, under the supervision of a psychiatrist.

Methods

Patients between the ages of 12 and 25 years with a diagnosis of ADHD and features of ODD, who are currently taking cannabis herbal extract (at a Δ⁹-tetrahydrocannabinol [THC]:cannabidiol [CBD] ratio of 1:20) as a treatment adjunct to stimulant pharmacotherapy will be recruited. A sample size of 10-20 individuals is estimated. The study interview will consist of (1) validated symptom rating scales (Swanson, Nolan, and Pelham-IV Questionnaire [SNAP-IV], 90-item; Patient Health Questionnaire, 9-item [PHQ-9]; and Screen for Child Anxiety Related Emotional Disorders [SCARED] tool to measure symptoms of ADHD and ODD, depression, and anxiety, respectively); (2) a semistructured interview to probe the experiences of using cannabis; and (3) a cannabis side effects survey. A cannabis product sample as well as 2 blood samples (a trough level and 2-hour postdose level) will be collected to measure plasma concentrations of cannabinoids and relevant metabolites (THC, CBD, 11-hydroxy-THC, 7-hydroxy-CBD, cannabichromene, and 11-nor-9-carboxy-THB) using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Self-report rating scales (SNAP-IV, SCARED, and PHQ-9) will be scored in accordance with standard protocols and compared to retrospective scores obtained from the participant’s chart. Demographic variables (age, weight, and race), symptom scores, and blood levels (peaks and troughs) of THC, CBD, cannabichromene (CBC), and metabolites will be summarized using descriptive statistics. Relationships between plasma concentrations and symptom scores will be determined using analysis of variance, and multiple regression analysis will be performed to determine associations between plasma concentrations and demographic variables (age, weight, and ethnicity). The qualitative data will be audio-recorded and transcribed and organized into themes.

Results

The protocol was approved by the Biomedical Research Ethics Board at the University of Saskatchewan (protocol #1726), and recruitment began in May 2021.

Conclusions

This proof-of-concept study will explore the potential treatment effectiveness of medical cannabis in participants with ADHD and ODD through a mixed methods approach to inform future research in this area.

International Registered Report Identifier (IRRID)

DERR1-10.2196/31281

The Effects of Cannabis Use on Cognitive Function in Healthy Aging: A Systematic Scoping Review

BACKGROUND

Older adults (≥50 years) represent the fastest-growing population of people who use cannabis, potentially due to the increasing promotion of cannabis as medicine by dispensaries and cannabis websites. Given healthy aging and cannabis use are both associated with cognitive decline, it is important to establish the effects of cannabis on cognition in healthy aging.

OBJECTIVE

This systematic scoping review used preferred reporting items for systematic reviews and meta-analyses guidelines to critically examine the extent of literature on this topic and highlight areas for future research.

METHOD

A search of six databases (PubMed, EMBASE, PsycINFO, Web of Science, Family and Society Studies Worldwide, and CINAHL) for articles published by September 2019, yielded 1,014 unique results.

RESULTS

Six articles reported findings for older populations (three human and three rodent studies), highlighting the paucity of research in this area. Human studies revealed largely null results, likely due to several methodological limitations. Better-controlled rodent studies indicate that the relationship between ∆9-tetrahydrocannabinol (THC) and cognitive function in healthy aging depends on age and level of THC exposure. Extremely low doses of THC improved cognition in very old rodents. Somewhat higher chronic doses improved cognition in moderately aged rodents. No studies examined the effects of cannabidiol (CBD) or high-CBD cannabis on cognition.

CONCLUSIONS

This systematic scoping review provides crucial, timely direction for future research on this emerging issue. Future research that combines neuroimaging and cognitive assessment would serve to advance understanding of the effects of age and quantity of THC and CBD on cognition in healthy aging.

Patterns of Cannabis Use Among Individuals with Obsessive-Compulsive Disorder: Results from an Internet Survey

BACKGROUND

Americans increasingly use cannabis, including those with psychiatric disorders. Yet little is known about cannabis use among individuals with obsessive-compulsive disorder (OCD). Thus, we conducted the first survey of cannabis users with OCD.

METHODS

Adults with OCD (i.e., prior professional diagnosis and/or score above the cutoff on a validated scale) who reported using cannabis were recruited from internet sources to complete a survey querying demographic information, medical/psychiatric history, cannabis use patterns, and perceived cannabis effects.

RESULTS

Of 1096 survey completers, 601 met inclusion criteria. Inhalation/cannabis flower were the most common method/formulation participants endorsed; most identified using high-potency cannabis products; 42% met criteria for cannabis use disorder. Nearly 90% self-reported using cannabis medicinally, 33.8% had a physician's recommendation, and 29% used specifically to manage OCD symptoms. Most participants reported cannabis improved obsessions/compulsions; those with increased obsession severity perceived less benefit. Finally, most participants were not receiving evidence-based OCD treatment, and the odds of receiving treatment decreased with increased cannabis use.

CONCLUSIONS

In this survey, participants with OCD reported both subjective benefits and harms from cannabis use. Future research should clarify the risks and benefits of cannabis use to those with OCD and develop treatment models to better support this population.

Impact of cannabis use on outcomes of patients admitted to an involuntary psychiatric unit: A retrospective cohort study

INTRODUCTION

Cannabis is associated with an increased risk of mental disorders, including the onset or adverse evolution of schizophrenia, bipolar disorder and depression. The aim of our study was to examine how cannabis use influences length of stay and readmissions in a unit of involuntary care.

METHOD

All patients admitted to one secure adult psychiatry unit in France in 2016 were included (n = 370). Patients were assigned to one of two groups according to detection of urinary tetrahydrocannabinol (THC + or -). Clinical outcomes, such as length of stay and readmissions, were compared between the groups in multivariate analyses.

RESULTS

We identified 130 THC + patients and 240 THC- patients. THC + patients were often young men. In adjusted analyses, THC + status was significantly associated with one-year readmissions (OR = 2.29, p = .0082) and more prescriptions of benzodiazepines (OR = 1.93, p = .02), but not antipsychotics, at discharge.

CONCLUSIONS

Cannabis users seem to have a particular profile in secure units, and are associated with specific diagnoses and treatments, and a higher risk of readmissions. Adapted management strategies might be warranted for these patients.

Cannabis use, abuse, and withdrawal: Cannabinergic mechanisms, clinical, and preclinical findings

Cannabis sativa is the most widely used illicit drug in the world. Its main psychoactive component is delta-9-tetrahydrocannabinol (THC), one of over 100 phytocannabinoid compounds produced by the cannabis plant. THC is the primary compound that drives cannabis abuse potential and is also used and prescribed medically for therapeutic qualities. Despite its therapeutic potential, a significant subpopulation of frequent cannabis or THC users will develop a drug use syndrome termed cannabis use disorder. Individuals suffering from cannabis use disorder exhibit many of the hallmarks of classical addictions including cravings, tolerance, and withdrawal symptoms. Currently, there are no efficacious treatments for cannabis use disorder or withdrawal symptoms. This makes both clinical and preclinical research on the neurobiological mechanisms of these syndromes ever more pertinent. Indeed, basic research using animal models has provided valuable evidence of the neural molecular and cellular actions of cannabis that mediate its behavioral effects. One of the main components being central action on the cannabinoid type-one receptor and downstream intracellular signaling related to the endogenous cannabinoid system. Back-translational studies have provided insight linking preclinical basic and behavioral biology research to better understand symptoms observed at the clinical level. This narrative review aims to summarize major research elucidating the molecular, cellular, and behavioral manifestations of cannabis/THC use that play a role in cannabis use disorder and withdrawal.

Human Laboratory Models of Cannabis Use: Applications for Clinical and Translational Psychiatry Research

Cannabis is increasingly used by individuals with mental health diagnoses and often purported to treat anxiety and various other psychiatric symptoms. Yet support for using cannabis as a psychiatric treatment is currently limited by a lack of evidence from rigorous placebo-controlled studies. While regulatory hurdles and other barriers make clinical trials of cannabis challenging to conduct, addiction researchers have decades of experience studying cannabis use in human laboratory models. These include methods to control cannabis administration, to delineate clinical and mechanistic aspects of cannabis use, and to evaluate potential treatment applications for cannabis and its constituents. In this paper, we review these human laboratory procedures and describe how each can be applied to study cannabis use in patients with psychiatric disorders. Because anxiety disorders are among the most common psychiatric illnesses affecting American adults, and anxiety relief is also the most commonly-reported reason for medicinal cannabis use, we focus particularly on applying human laboratory models to study cannabis effects in individuals with anxiety and related disorders. Finally, we discuss how these methods can be integrated to study cannabis effects in other psychiatric conditions and guide future research in this area.

Dissecting the role of CB1 and CB2 receptors in cannabinoid reward versus aversion using transgenic CB1- and CB2-knockout mice

Cannabinoids produce both rewarding and aversive effects in humans and experimental animals. However, the mechanisms underlying these conflicting findings are unclear. Here we examined the potential involvement of CB1 and CB2 receptors in cannabinoid action using transgenic CB1-knockout (CB1-KO) and CB2-knockout (CB2-KO) mice. We found that Δ9-tetrahydrocannabinol (Δ9-THC) induced conditioned place preference at a low dose (1 mg/kg) in WT mice that was attenuated by deletion of the CB1 receptor. At 5 mg/kg, no subjective effects of Δ9-THC were detected in WT mice, but CB1-KO mice exhibited a trend towards place aversion and CB2-KO mice developed significant place preferences. This data suggests that activation of the CB1 receptor is rewarding, while CB2R activation is aversive. We then examined the nucleus accumbens (NAc) dopamine (DA) response to Δ9-THC using in vivo microdialysis. Unexpectedly, Δ9-THC produced a dose-dependent decrease in extracellular DA in WT mice, that was potentiated in CB1-KO mice. However, in CB2-KO mice Δ9-THC produced a dose-dependent increase in extracellular DA, suggesting that activation of the CB2R inhibits DA release in the NAc. In contrast, Δ9-THC, when administered systemically or locally into the NAc, failed to alter extracellular DA in rats. Lastly, we examined the locomotor response to Δ9-THC. Both CB1 and CB2 receptor mechanisms were shown to underlie Δ9-THC-induced hypolocomotion. These findings indicate that Δ9-THC's variable subjective effects reflect differential activation of cannabinoid receptors. Specifically, the opposing actions of CB1 and CB2 receptors regulate cannabis reward and aversion, with CB2-mediated effects predominant in mice.

Cannabis vaping: Understanding the health risks of a rapidly emerging trend

The rapid emergence of youth vaping has completely changed the landscape of adolescent substance use in Canada and has become a pressing public health issue of our time. While nicotine remains the most common substance encountered in vaping devices, cannabis vaping is now reported by one-third of youth who vape. Though cannabis vaping is thought to generate fewer toxic emissions than cannabis smoking, it has been associated with several cases of acute lung injury and often involves high-potency forms of cannabis, exposing youth to several acute and long-term health risks. The low perceived riskiness of cannabis as a substance and of vaping as a mode of consumption may bring a false sense of security and be particularly appealing for youth who may be looking for a 'healthier way' to use substances. While research is still lacking on how best to support youth who may have already initiated cannabis vaping, concerted efforts among paediatric providers, public health experts, schools, communities, and families are urgently needed to limit the spread of cannabis vaping among Canadian youth.

Association of Cannabis Use With Intimate Partner Violence Among Couples With Substance Misuse

BACKGROUND AND OBJECTIVES

There is a well-established causal link between substance use and intimate partner violence (IPV) perpetration and victimization. However, little is known about the complex emerging relationship between cannabis use and IPV. Because cannabis is the most commonly used drug in the United States and is associated with numerous IPV risk factors such as alcohol use, it is important to examine this relationship in greater detail.

METHOD

The current exploratory study examined the association between (a) self-reported cannabis use during the past 90 days and (b) Δ9-tetrahydrocannabinol (THC) urine drug screens and IPV perpetration and victimization in a sample of 30 alcohol or drug-misusing community couples (N = 60 individual participants).

RESULTS

The majority of participants (n = 50 individuals, 83.3%) had concordant cannabis self-reported and urine drug screen results. After accounting for demographic variables and quantity and frequency of alcohol and stimulant use, greater quantity and frequency of cannabis use as well as positive THC urine drug screen results were associated with greater physical IPV victimization, and greater quantity and frequency of cannabis were associated with greater IPV psychological victimization and perpetration, and physical IPV victimization. CONCLUSION AND SCIENTIFIC SIGNIFICANCE: Findings emphasize the unique and important role that cannabis plays in the occurrence of IPV among intact couples. Findings also underscore the feasibility and utility of integrating confirmatory biological samples into future studies on this topic in order to advance the science in this area. (Am J Addict 2020;00:00-00).

Use of cannabinoid-based medicine among older residential care recipients diagnosed with dementia: study protocol for a double-blind randomised crossover trial

BACKGROUND

Dementia is a neurological condition that affects the cognitive and functional ability of the brain and is the leading cause of disability among those aged 65 years and above. More effective ways to manage dementia symptoms are needed because current treatment options (antidepressants and antipsychotics) can be ineffective and are associated with substantial side effects, including increased rate of mortality. Cannabinoid-based medicine (CBM) has shown an ability to inhibit some symptoms associated with dementia, and the adverse effects are often minimal; yet, little research has explored the use of CBM among this population.

AIM

To monitor the safety of a purified dose of CBM oil (3:2 delta-9-tetrahydrocannabinol:cannabidiol) on behaviour symptoms, quality of life and discomfort caused by pain.

METHODS/DESIGN

We will carry out an 18-week, randomised, double-blind crossover trial that consists of a 2-week eligibility period, two 6-week treatment cycles, and two 2-week washout periods (between both cycles and after the second treatment cycle). We aim to recruit 50 participants with dementia who are living in residential aged-care facilities. The participants will be randomised into two groups and will receive a dose of either CBM oil or placebo for the first treatment cycle and the opposite medication for the second. Data will be collected using the Neuropsychiatric Inventory Questionnaire, the Cohen-Mansfield Agitation Inventory, the Quality of Life in Alzheimer's Disease questionnaire, and the Abbey Pain Scale on seven occasions. These will be completed by the participants, aged-care staff, and nominated next of kin or family members. The participants' heart rate and blood pressure will be monitored weekly, and their body composition and weight will be monitored fortnightly by a research nurse, to assess individual dose response and frailty. In addition, pre- and post-surveys will be administered to aged-care staff and family members to understand their perceptions of CBM and to inform proposed focus groups consisting of the aged-care staff and next of kin.

DISCUSSION

The study design has been informed by medical professionals and key stakeholders, including those working in the residential aged-care industry to ensure patient safety, collection of non-invasive measures, and methodological rigor and study feasibility.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12619000474156. Registered on 21 March 2019.

Overbaked: assessing and predicting acute adverse reactions to Cannabis

Background

Trends toward legalizing cannabis may increase experimentation with the drug among less experienced users with limited knowledge of possible adverse reactions. This study explores the prevalence, frequency, and levels of distress produced by various acute adverse reactions to cannabis, as well as predictors of these reactions.

Methods

The Adverse Reactions Scale (ARS) was created and administered to a large sample of undergraduate college students (n = 999) who were predominantly white (> 70%), female (> 70%), recreational (> 90%) cannabis users. The ARS was administered in an anonymous online survey measuring demographics, cannabis use patterns, cannabis use motives, personality, and negative affect.

Results

The most prevalent adverse reactions to cannabis were coughing fits, anxiety, and paranoia, which > 50% of the sample reported experiencing. The most frequently occurring reactions were coughing fits, chest/lung discomfort, and body humming, which occurred on approximately 30–40% of cannabis use sessions. Panic attacks, fainting, and vomiting were rated as the most distressing, with mean ratings falling between “moderately” and “quite” distressing. Multiple regression analyses revealed that lower frequency of cannabis use predicted increased frequency of adverse reactions. Symptoms of cannabis use disorder, conformity motives, and anxiety sensitivity were significant predictors of both the prevalence of, and distress caused by, adverse reactions.

Conclusions

Relative to past research, this study provides a more comprehensive account of possible adverse reactions to cannabis, and individual difference variables that predict these reactions. This study has implications for inexperienced cannabis users, as well as medical professionals and budtenders who provide information about cannabis use.

A Systematic Review of the Neurocognitive Effects of Cannabis Use in Older Adults

Purpose of Review

Older adults currently represent the fastest growing demographic of cannabis users, yet few studies have investigated the effects of cannabis use on cognitive functioning in aging. We conducted a systematic review of the recent literature examining cognitive outcomes associated with cannabis use in older adults, with and without neurocognitive disorders, to clarify the potential neuroprotective benefits and risks of cognitive decline in this population.

Recent Findings

We identified 26 studies examining cognitive outcomes associated with medical and recreational use of cannabis in healthy aging, dementia, Parkinson's disease, multiple sclerosis, HIV, and pain populations. Although variability in the cannabis products used, outcomes assessed, and study quality limits the conclusions that can be made, modest reductions in cognitive performance were generally detected with higher doses and heavier lifetime use.

Summary

This review highlights the need for additional high-quality research using standardized, validated assessments of cannabis exposure and cognitive outcomes. Reliable measures and longitudinal data are necessary to better characterize the effects of cannabis use on cognitive aging, as well as differential effects of recreational and medical cannabis.

Age related differences in cannabis use and subjective effects in a large population-based survey of adult athletes

BACKGROUND

There is a paucity of information regarding cannabis use behaviors in adult community-based athletes as most research in athletes has focused on misuse of cannabis in elite, adolescent, university-based athletes. We aimed to determine whether age related differences exist in patterns of cannabis use and subjective effects to cannabis in adult athletes.

METHODS

The Athlete PEACE Survey used mainly social media and email blasts to recruit and SurveyGizmo to collect data. Cannabis patterns of use (duration of use, frequency of use, routes of administration, cannabinoid used, concurrent use with exercise), benefits, and adverse effects were reported. Age was reported by decade from 21 to ≥60. Age trends in cannabis use patterns and subjective effects were assessed using linear trend analysis.

RESULTS

Of the 1161 participants, 301 (26%) athletes currently used cannabis. Younger athletes compared to older athletes reported significantly more positive and adverse subjective effects to cannabis, used cannabis longer, and used both tetrahydrocannabinol and cannabidiol for medical and recreational purposes. Younger athletes used cannabis concurrently with exercise more often than older athletes and consumed edibles, vaporized, and smoked more than older athletes.

CONCLUSIONS

We found age-related cannabis patterns of use and subjective effects to cannabis. Concerns about cannabis mis-use and abuse in athletes maybe overstated with the potential benefits (improved sleep, decreased anxiety, less pain) outweighing the adverse effects (increased anxiety, increased appetite, difficulty concentrating).

Cue Reactivity in the Ventral Striatum Characterizes Heavy Cannabis Use, Whereas Reactivity in the Dorsal Striatum Mediates Dependent Use

BACKGROUND

Animal models of addiction suggest that the transition from incentive-driven drug use to habitual and ultimately compulsive drug use is mediated by a shift from ventral to dorsal striatal cue control over drug seeking. Previous studies in human cannabis users reported elevated trait impulsivity and neural cue reactivity in striatal circuits; however, these studies were not able to separate addiction-related from exposure-related adaptations.

METHODS

To differentiate the adaptive changes, the current functional magnetic resonance imaging study examined behavioral and neural cue reactivity in dependent (n = 18) and nondependent (n = 20) heavy cannabis users and a nonusing reference group (n = 44).

RESULTS

Irrespective of dependence status, cannabis users demonstrated elevated trait impulsivity as well as increased ventral striatal reactivity and striatal frontal coupling in response to drug cues. Dependent users selectively exhibited dorsal striatal reactivity and decreased striatal limbic coupling during cue exposure. An exploratory analysis revealed that higher ventral caudate neural cue reactivity was associated with stronger cue-induced arousal and craving in dependent users, whereas this pattern was reversed in nondependent users.

CONCLUSIONS

Taken together, the current findings suggest that exaggerated responses of the ventral striatal reward system may promote excessive drug use in humans, whereas adaptations in dorsal striatal systems engaged in habit formation may promote the transition to addictive use.