Determining the magnitude and duration of acute Δ9-tetrahydrocannabinol (Δ9-THC)-induced driving and cognitive impairment: A systematic and meta-analytic review

Does acute cannabidiol (CBD) use impair performance? A meta-analysis and comparison with placebo and delta-9-tetrahydrocannabinol (THC)

Cannabidiol (CBD) is widely used and believed to be non-intoxicating, lacking acute performance effects (e.g., non-impairing). However, a synthesis of data has not evaluated this. This meta-analysis synthesized data from controlled human laboratory studies that evaluated if acute CBD use impairs performance. Performance on objective and subjective measures of cognitive and psychomotor function were used as markers for potential performance changes and impairment. Studies were identified through systematic database searches. Adult clinical trials measuring acute CBD effects (within 0-8 h of administration) were included. The primary outcome was the peak mean difference in performance measures between CBD and placebo. A secondary analysis utilizing delta-9-tetrahydrocannabinol (Δ9-THC) as a positive control for comparison to CBD was completed. Pooled Hedges' g estimates were calculated using robust variance estimation (RVE) meta-regression. The omnibus RVE meta-analysis indicated a statistically significant, but small effect size (Hedge's g < 0.2) for impaired performance following acute CBD consumption compared to placebo (N = 16 trials, Hedges' g = 0.122, 95% CI: 0.023-0.221, p = 0.019). Measure type was a significant moderator with larger mean differences between CBD and placebo when subjective measures, specifically self-reported sedation, were used versus objective performance tasks (Hedges' gSubjective = 0.288 versus Hedges' gObjective = 0.048). Δ9-THC had a significantly greater magnitude of impairment compared to CBD (N = 8, Hedges' g = 0.416, 95% CI: 0.017-0.816, p = 0.043). In summary, acute CBD consumption was associated with a small increase in subjective ratings of sedation, but no difference from placebo was observed across multiple domains of objectively assessed cognitive or psychomotor performance. These findings suggest that acute CBD alone is unlikely to significantly impair daily functioning or workplace performance.

Intoxication due to Δ9-tetrahydrocannabinol is characterized by disrupted prefrontal cortex activity

Neural states of impairment from intoxicating substances, including cannabis, are poorly understood. Cannabinoid 1 receptors, the main target of Δ9-tetrahydrocannabinol (THC), the primary intoxicating cannabinoid in cannabis, are densely localized within prefrontal cortex; therefore, prefrontal brain regions are key locations to examine brain changes that characterize acute intoxication. We conducted a double-blind, randomized, cross-over study in adults, aged 18-55 years, who use cannabis regularly, to determine the effects of acute intoxication on prefrontal cortex resting-state measures, assessed with portable functional near-infrared spectroscopy. Participants received oral THC (10-80 mg, individually dosed to overcome tolerance and achieve acute intoxication) and identical placebo, randomized for order; 185 adults were randomized and 128 completed both study days and had usable data. THC was associated with expected increases in subjective intoxication ratings (ES = 35.30, p < 0.001) and heart rate (ES = 11.15, p = 0.001). THC was associated with decreased correlations and anticorrelations in static resting-state functional connectivity within the prefrontal cortex relative to placebo, with weakest correlations and anticorrelations among those who reported greater severity of intoxication (RSFC between medial PFC-ventromedial PFC and DEQ scores, r = 0.32, p < 0.001; RSFC between bilateral mPFC and DEQ scores, r = -0.28, p = 0.001). Relative to placebo, THC was associated with increased variability (or reduced stability) in dynamic resting-state functional connectivity of the prefrontal cortex at p = 0.001, consistent across a range of window sizes. Finally, using frequency power spectrum analyses, we observed that relative to placebo, THC was associated with widespread reduced spectral power within the prefrontal cortex across the 0.073-0.1 Hz frequency range at p < 0.039. These neural features suggest a disruptive influence of THC on the neural dynamics of the prefrontal cortex and may underlie cognitive impairing effects of THC that are detectable with portable imaging. This study is registered in Clinicaltrials.gov (NCT03655717).

Randomized Laboratory Study of Single-Dose Cannabis, Dronabinol, and Placebo in Patients With Schizophrenia and Cannabis Use Disorder

BACKGROUND AND HYPOTHESIS

Up to 43% of people with schizophrenia have a lifetime cannabis use disorder (CUD). Tetrahydrocannabinol (THC) has been shown to exacerbate psychosis in a dose-dependent manner, but little research has assessed its effects on schizophrenia and co-occurring CUD (SCZ-CUD). In this double-dummy, placebo-controlled trial (total n = 130), we hypothesized that a modest dose of THC would worsen cognitive function but not psychosis.

STUDY DESIGN

Effects of single-dose oral THC (15 mg dronabinol) or smoked 3.5% THC cigarettes vs placebo in SCZ-CUD or CUD-only on positive and negative symptoms of schizophrenia (only for SCZ-CUD), cognition, and drug experiences assessed several hours after drug administration. SCZ-only and healthy control participants were also assessed.

STUDY RESULTS

Drug liking was higher in THC groups vs placebo. Neither smoked THC nor oral dronabinol predicted positive or negative symptom subscale scores 2 and 5 h, respectively, after drug exposure in SCZ-CUD participants. The oral dronabinol SCZ-CUD group, but not smoked THC SCZ-CUD group, performed worse than placebo on verbal learning (B = -9.89; 95% CI: -16.06, -3.18; P = .004) and attention (B = -0.61; 95% CI: -1.00, -0.23; P = .002). Every 10-point increment in serum THC + THCC ng/ml was associated with increased negative symptoms (0.40 points; 95% CI: 0.15, 0.65; P = .001; subscale ranges 7-49) and trends were observed for worse positive symptoms and performance in verbal learning, delayed recall, and working memory.

CONCLUSIONS

In people with SCZ-CUD, a modest single dose of oral THC was associated with worse cognitive functioning without symptom exacerbation several hours after administration, and a THC dose-response effect was seen for negative symptoms.

Complexity of Translating Analytics to Recent Cannabis Use and Impairment

While current analytical methodologies can readily identify cannabis use, definitively establishing recent use within the impairment window has proven to be far more complex, requiring a new approach. Recent studies have shown no direct relationship between impairment and Δ9-tetra-hydrocannabinol (Δ9-THC) concentrations in blood or saliva, making legal "per se" Δ9-THC limits scientifically unjustified. Current methods that focus on Δ9-THC and/or metabolite concentrations in blood, saliva, urine, or exhaled breath can lead to false-positive results for recent use due to the persistence of Δ9-THC well outside of the typical 3-4 h window of potential impairment following cannabis inhalation. There is also the issue of impairment due to other intoxicating substances-just because a subject exhibits signs of impairment and cannabis use is detected does not rule out the involvement of other drugs. Compounding the matter is the increasing popularity of hemp-derived cannabidiol (CBD) products following passage of the 2018 Farm Bill, which legalized industrial hemp in the United States. Many of these products contain varying levels of Δ9-THC, which can lead to false-positive tests for cannabis use. Furthermore, hemp-derived CBD is used to synthesize Δ8-THC, which possesses psychoactive properties similar to Δ9-THC and is surrounded by legal controversy. For accuracy, analytical methods must be able to distinguish the various THC isomers, which have identical masses and exhibit immunological cross-reactivity. A new testing approach has been developed based on exhaled breath and blood sampling that incorporates kinetic changes and the presence of key cannabinoids to detect recent cannabis use within the impairment window without the false-positive results seen with other methods. The complexity of determining recent cannabis use that may lead to impairment demands such a comprehensive method so that irresponsible users can be accurately detected without falsely accusing responsible users who may unjustly suffer harsh, life-changing consequences.

A randomised, placebo-controlled, double blind, crossover trial on the effect of a 20:1 cannabidiol: Δ9-tetrahydrocannabinol medical cannabis product on neurocognition, attention, and mood

As cannabinoid-based medications gain popularity in the treatment of refractory medical conditions, it is crucial to examine the neurocognitive effects of commonly prescribed products to ensure associated safety profiles. The present study aims to investigate the acute effects of a standard 1 mL sublingual dose of CannEpil®, a medicinal cannabis oil containing 100 mg cannabidiol (CBD) and 5 mg Δ9-tetrahydrocannabinol (THC) on neurocognition, attention, and mood. A randomised, double-blind, placebo-controlled, within-subjects design assessed 31 healthy participants (16 female, 15 male), aged between 21 and 58 years, over a two-week experimental protocol. Neurocognitive performance outcomes were assessed using the Cambridge Neuropsychological Test Automated Battery, with the Profile of Mood States questionnaire, and the Bond-Lader Visual Analogue Scale used to assess subjective state and mood. CannEpil increased Total Errors in Spatial Span and Correct Latency (median) in Pattern Recognition Memory, while also increasing Efficiency Score (lower score indicates greater efficiency) relative to placebo (all p < .05). Subjective Contentedness (p < .01) and Amicability (p < .05) were also increased at around 2.5 h post dosing, relative to placebo. Drowsiness or sedative effect was reported by 23 % of participants between three to six hours post CannEpil administration. Plasma concentrations of CBD, THC, and their metabolites were not significantly correlated with any observed alterations in neurocognition, subjective state, or adverse event occurrence. An acute dose of CannEpil impairs select aspects of visuospatial working memory and delayed pattern recognition, while largely preserving mood states among healthy individuals. Intermittent reports of drowsiness and sedation underscore the inter-individual variability of medicinal cannabis effects on subjective state. (ANZCTR; ACTRN12619000932167; https://www.anzctr.org.au).

Risk of motor vehicle collision associated with cannabis and alcohol use among patients presenting for emergency care

BACKGROUND

The objective of this study was to examine the relationship between cannabis and alcohol use and occurrence of motor vehicle collision (MVC) among patients in the emergency department (ED).

METHODS

This was a cross-sectional study of visits to EDs in Denver, CO, Portland, OR, and Sacramento, CA by drivers who were involved in MVCs and presented with injuries (cases) and non-injured drivers (controls) who presented for medical care. We obtained blood samples and measured delta-9-THC and its metabolites. Alcohol levels were determined by breathalyzer or samples taken in the course of clinical care. Participants completed a research-assistant-administered interview consisting of questions about drug and alcohol use prior to their visit, context of use, and past-year drug and alcohol use. Multiple logistic regression was used to estimate the association between MVC and cannabis/alcohol use, adjusted for demographic characteristics. We then stratified participants based on levels of cannabis use and calculated the odds of MVC across these levels, first using self-report and then using blood levels for delta-9-THC in separate models. We conducted a case-crossover analysis, using 7-day look-back data to allow each participant to serve as their own control. Sensitivity analyses examined the influence of usual use patterns and driving in a closed (car, truck, van) versus open (motorcycle, motorbike, all-terrain vehicle) vehicle.

RESULTS

Cannabis alone was not associated with higher odds of MVC, while acute alcohol use alone, and combined use of alcohol and cannabis were both independently associated with higher odds of MVC. Stratifying by level of self-reported or measured cannabis use, higher levels were not associated with higher odds for MVC, with or without co-use of alcohol; in fact, high self-reported acute cannabis use was associated with lower odds of MVC (odds ratio [OR] 0.18, 95% confidence interval [CI] 0.05-0.65). In the case-crossover analysis, alcohol use alone or in combination with cannabis was associated with higher odds of MVC, while cannabis use alone was again associated with decreased odds of MVC.

CONCLUSIONS

Alcohol use alone or in conjunction with cannabis was consistently associated with higer odds for MVC. However, the relationship between measured levels of cannabis and MVC was not as clear. Emphasis on actual driving behaviors and clinical signs of intoxication to determine driving under the influence has the strongest rationale.

Detection of Δ9 -tetrahydrocannabinol (THC) in oral fluid using two point-of-collection testing devices following oral administration of a THC and cannabidiol containing oil

Point-of-collection testing (POCT) devices are widely used in roadside and workplace drug testing to identify recent cannabis use by measuring the presence of Δ9 -tetrahydrocannabinol (THC) in oral fluid (OF). However, the performance of POCT devices with oral medicinal cannabis products remains poorly described. In a randomised, double-blinded, crossover trial, adults with insomnia disorder (n = 20) received a single (2 mL) oral dose of oil containing 10 mg THC + 200 mg cannabidiol, or placebo, prior to sleep. Participants were tested with the Securetec DrugWipe® 5S (10 ng/mL THC cut-off) and Dräger DrugTest® 5000 (25 ng/mL THC cut-off) POCT devices at baseline (pre-treatment) and then at 0.5, 10, and 18 h post-treatment. An OF sample, taken at each time point, was also analysed using liquid chromatography-tandem mass spectrometry. Large individual variability in OF THC concentrations was observed 0.5 h post-treatment (range: 0-425 ng/mL; mean (SD) 48.7 (107.5) ng/mL). Both the Securetec DrugWipe® 5S and DrugTest® 5000 demonstrated poor sensitivity to THC at 0.5 h post-treatment (25% and 50%, respectively). At 10 and 18 h post-treatment, all participant OF THC concentrations were below screening cut-offs, and all test results were negative. These findings highlight the relatively poor sensitivity of both devices in detecting recent use of an oral medicinal cannabis product. They also suggest a low probability of obtaining a positive THC result the morning after ('one-off') use. Further research is required to establish the probability of obtaining a positive THC result with regular medicinal cannabis use.

Effects of acute cannabis inhalation on reaction time, decision-making, and memory using a tablet-based application

BACKGROUND

Acute cannabis use has been demonstrated to slow reaction time and affect decision-making and short-term memory. These effects may have utility in identifying impairment associated with recent use. However, these effects have not been widely investigated among individuals with a pattern of daily use, who may have acquired tolerance. The purpose of this study was to examine the impact of tolerance to cannabis on the acute effects as measured by reaction time, decision-making (gap acceptance), and short-term memory.

METHODS

Participants (ages 25-45) completed a tablet-based (iPad) test battery before and approximately 60 min after smoking cannabis flower. The change in performance from before to after cannabis use was compared across three groups of cannabis users: (1) occasional use (n = 23); (2) daily use (n = 31); or (3) no current use (n = 32). Participants in the occasional and daily use group self-administered ad libitum, by smoking or vaping, self-supplied cannabis flower with a high concentration of total THC (15-30%).

RESULTS

The occasional use group exhibited decrements in reaction time (slowed) and short-term memory (replicated fewer shapes) from before to after cannabis use, as compared to the no-use group. In the gap acceptance task, daily use participants took more time to complete the task post-smoking cannabis as compared to those with no use or occasional use; however, the level of accuracy did not significantly change.

CONCLUSIONS

The findings are consistent with acquired tolerance to certain acute psychomotor effects with daily cannabis use. The finding from the gap acceptance task which showed a decline in speed but not accuracy may indicate a prioritization of accuracy over response time. Cognitive and psychomotor assessments may have utility for identifying impairment associated with recent cannabis use.

Cannabis use disorder contributes to cognitive dysfunction in Veterans with traumatic brain injury

Background

While emerging evidence supports a link between traumatic brain injury (TBI) and progressive cognitive dysfunction in Veterans, there is insufficient information on the impact of cannabis use disorder (CUD) on long-term cognitive disorders. This study aimed to examine the incidences of cognitive disorders in Veterans with TBI and CUD and to evaluate their relationship.

Methods

This retrospective cohort study used the US Department of Veterans Affairs and Department of Defense administrative data from the Long-term Impact of Military-Relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium Phenotype study. Diagnoses suggesting cognitive disorders after a TBI index date were identified using inpatient and outpatient data from 2003 to 2022. We compared the differential cognitive disorders incidence in Veterans who had the following: (1) no CUD or TBI (control group), (2) CUD only, (3) TBI only, and (4) comorbid CUD+TBI. Kaplan-Meier analyses were used to estimate the overall cognitive disorders incidence in the above study groups. The crude and adjusted Cox proportional hazards models were used to estimate crude and adjusted hazard ratios (HRs) for cognitive disorders.

Results

A total of 1,560,556 Veterans [82.32% male, median (IQR) age at the time of TBI, 34.51 (11.29) years, and 61.35% white] were evaluated. The cognitive disorder incidence rates were estimated as 0.68 (95% CI, 0.62, 0.75) for CUD only and 1.03 (95% CI, 1.00, 1.06) for TBI only per 10,000 person-months of observations, with the highest estimated cognitive disorder incidence observed in participants with both TBI and CUD [1.83 (95% CI, 1.72, 1.95)]. Relative to the control group, the highest hazard of cognitive disorders was observed in Veterans with CUD+TBI [hazard ratio (HR), 3.26; 95% CI, 2.91, 3.65], followed by those with TBI only (2.32; 95 CI%, 2.13, 2.53) and with CUD (1.79; 95 CI%, 1.60, 2.00). Of note, in the CUD only subgroup, we also observed the highest risk of an early onset cognitive disorder other than Alzheimer's disease and Frontotemporal dementia.

Discussion

The results of this analysis suggest that individuals with comorbid TBI and CUD may be at increased risk for early onset cognitive disorders, including dementia.

Accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking

INTRODUCTION

Cannabis intoxication may increase the risk of motor vehicle crashes. However, reliable methods of assessing cannabis intoxication are limited. The presence of eyelid tremors is among the signs of cannabis use identified under the Drug Evaluation and Classification Program of the International Association of Chiefs of Police. Our objectives were to assess the accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking using a blinded, controlled study design.

METHODS

Adult subjects (N = 103) were recruited into three groups based on their cannabis use history: daily, occasional, and no current cannabis use. Participants' closed eyelids were video recorded for 30 seconds by infrared videography goggles before and at a mean ± standard deviation time of 71.4 ± 4.6 minutes after the onset of a 15-minute interval of ad libitum cannabis flower smoking or vaping. Three observers with expertise in neuro-ophthalmology and medical toxicology were trained on exemplar videos of eyelids to reach a consensus on how to grade eyelid tremor. Without knowledge of subjects' cannabis use history or time point (pre- or post-smoking), observers reviewed each video for eyelid tremor graded as absent, slight, moderate, or severe. During subsequent data analysis, this score was further dichotomized as a consensus score of absent (absent/slight) or present (moderate/severe).

RESULTS

Kappa and intraclass correlation coefficient statistics demonstrated moderate agreement among the coders, which ranged from 0.44-0.45 and 0.58-0.61, respectively. There was no significant association between recent cannabis use and the observers' consensus assessment that eyelid tremor was present, and cannabis users were less likely to have tremors (odds ratio: 0.75; 95 percent confidence interval: 0.25, 2.40). The assessment of eyelid tremor as an indicator of recent cannabis smoking had a sensitivity of 0.86, specificity of 0.18, and accuracy of 0.64.

DISCUSSION

Eyelid tremor has fair sensitivity but poor specificity and accuracy for identification of recent cannabis use. Inter-rater reliability for assessment of eyelid tremor was moderate for the presence and degree of tremor. The weak association between recent cannabis use and eyelid tremor does not support its utility in identifying recent cannabis use.

LIMITATIONS

Videos were recorded at only one time point after cannabis use. Adherence to abstinence could not be strictly supervised. Due to regulatory restrictions, we were unable to control the cannabis product used or administer a fixed Δ9-tetrahydrocannabinol dose. Participants were predominately non-Hispanic and White.

CONCLUSIONS

In a cohort of participants with a range of cannabis use histories, acute cannabis smoking was not associated with the presence of eyelid tremor, regardless of cannabis use history, at 70 minutes post-smoking. Additional research is needed to identify the presence of eyelid tremor accurately, determine the relationship between cannabis dose and timeline in relation to last cannabis use to eyelid tremor, and determine how it should be, if at all, utilized for cannabis Drug Recognition Evaluator examinations.

Acute administration of alprazolam, alcohol and their combination on cognitive performance and mood: A randomised, double-blind, placebo-controlled study

BACKGROUND

Recreational co-consumption of benzodiazepines and alcohol is a common practise; yet, the cognitive effects of this combination remain poorly understood. This study aimed to investigate the acute cognitive effects of combining a 1 mg dose of alprazolam with a moderate dose of alcohol (target 0.04% blood alcohol concentration (BAC)) in a non-clinical population.

METHODS

In this randomised, double-blind, placebo-controlled, crossover trial, participants completed computerised cognitive assessments and the brief biphasic alcohol effects scale (B-BAES) after consuming 1 mg of alprazolam, both with and without a moderate dose of alcohol (target 0.04% BAC).

RESULTS

Among 20 healthy participants (mean age = 28.6, SD ± 4.0 years, 60% female), we found that a peak BAC of 0.03% had no significant impact on cognitive performance. Both the individual use of alprazolam and its combination with alcohol resulted in impaired reaction time, digit vigilance, and verbal, spatial and numeric working memory tasks, although an additive effect when alcohol and alprazolam were consumed together was not evident. The most pronounced cognitive effects occurred at 100 min after dosing, coinciding with increased alprazolam concentrations. Sedative effects were heightened with alcohol, alprazolam and their combination while no stimulative effects were reported.

CONCLUSIONS

Our findings highlight the significant implications of a therapeutic dose of alprazolam on impairing cognitive performance. This is particularly relevant considering the frequency of non-medical alprazolam use. Future studies should explore different dosages, administration timings and long-term effects to inform the development of public health policies and guidelines regarding the combined use of alcohol and benzodiazepines.

A two-sample approach to retrograde extrapolation of blood THC concentrations - Is it feasible?

BACKGROUND

Retrograde extrapolation of drug concentrations in blood can be relevant in cases of drug-impaired driving and is regularly used in forensic toxicology in Norway. Δ9-tetrahydrocannabinol (THC) has complex, multi-compartmental pharmacokinetics, which makes retrograde extrapolation of blood THC concentrations problematic. In the present study, we evaluated an approach to retrograde extrapolation in which momentary rates of decrease of THC were estimated from two consecutive blood samples in apprehended drivers.

MATERIAL AND METHODS

Data were collected from apprehended drivers in Norway 2000-2020. We included 548 cases in which THC was detected in two consecutive blood samples collected ≥ 20 min apart. THC concentrations were measured by GC-MS and UHPLC-MS/MS. In each case, THC concentrations and the time between the two sampling points (Δt) were used to estimate the rate constant k. The relationship between THC concentration and k was modelled by linear regression.

RESULTS

The median Δt was 31 min (interquartile range, IQR = 9). The median blood THC concentration was 2.4 μg/L (IQR = 3.4) at the first sampling point and 2.3 μg/L (IQR =3.1) at the second. The concentration decreased in 62% and increased in 38% of all cases. However, considering measurement uncertainty, the changes were not statistically significant in 87% of cases. The mean of k was 0.12 h-1, corresponding to an apparent t1/2 of 6.0 h. The t1/2 predicted from linear regression of k against THC concentration ranged from 0.93 to 13 h for the highest and lowest concentrations observed (36 and 0.63 μg/L, respectively). The time from driving to blood collection had a median of 1.7 h (IQR = 1.5), and did not correlate with k.

CONCLUSIONS

The apparent t1/2 of THC calculated from the mean of k was 6.0 h, which is shorter than the terminal elimination t1/2 suggested in previous population studies. This indicates that blood samples were often taken during the late distribution phase of THC. Because Δt was short relative to the rates of decrease expected in the late distribution and elimination phases, the underlying true concentration changes related to in vivo pharmacokinetics were small and masked by the relatively larger "false" changes introduced by random analytical and pre-analytical error. Therefore, individual values of k calculated from only two blood samples taken a short time apart are unreliable, and a two-sample approach to retrograde extrapolation of THC cannot be recommended.

An overview on synthetic and biological activities of cannabidiol (CBD) and its derivatives

(-)-Cannabidiol is a class of non-psychoactive plant cannabinoids derived from cannabis plants. Currently, Epidiolex (Cannabidiol) has been approved by the FDA for the treatment of two rare and severe forms of epilepsy related diseases, namely Lennox-Gastaut syndrome (LGS) and Dravet (DS). In addition, Cannabidiol and its structural analogues have received increasing attention due to their potential therapeutic effects such as neuroprotection, anti-epilepsy, anti-inflammation, anti-anxiety, and anti-cancer. Based on literature review, no comprehensive reviews on the synthesis of Cannabidiol and its derivatives have been found in recent years. Therefore, this article summarizes the published synthesis methods of Cannabidiol and the synthesis routes of Cannabidiol derivatives, and introduces the biological activities of some Cannabidiol analogues that have been studied extensively and have significant activities.

A Semi-Naturalistic, Open-Label Trial Examining the Effect of Prescribed Medical Cannabis on Neurocognitive Performance

BACKGROUND AND OBJECTIVES

Medical cannabis use is increasing in Australia and other jurisdictions, yet little is known about the effects of medical cannabis on cognitive function. Findings from studies of non-medical ('recreational') cannabis may not be applicable to patients using prescribed medical cannabis to manage a health condition.

METHODS

In this semi-naturalistic, open-label trial, patients with various health conditions attended a single laboratory session in which they self-administered a standard dose of prescribed medical cannabis as per instructions on the pharmacy label. We assessed cognitive performance using the Cambridge Neuropsychological Test Automated Battery (CANTAB) and Druid application (app) prior to and following (CANTAB: + 3 h; Druid: + 3 and 5.5 h) medical cannabis self-administration. We also assessed subjective drug effects prior to and following (1, 2 and 4 h) medical cannabis self-administration using a range of 0-10 cm visual analogue scales ('stoned', 'sedated', 'relaxed', 'comfortable', 'anxious' and 'confident'). Data were analyzed using linear fixed-effect models.

RESULTS

Participants (N = 40; 22 females) were prescribed a range of products including orally administered oils (n = 23) and flower for vaporization (n = 17). Participants had a mean (standard deviation [SD]) age of 41.38 (12.66) years and had been using medical cannabis for a mean (SD) of 10.18 (8.73) months. Chronic non-cancer pain was the most common indication for medical cannabis use (n = 20), followed by sleep disorder (n = 18) and anxiety (n = 11). The mean (SD) delta-9-tetrahydrocannabinol (THC)/cannabidiol (CBD) dose administered by participants was 9.61 (8.52) mg/9.15 (10.11) mg among those using an oil, and 37.00 (24.53) mg/0.38 (1.58) mg among those who vaporized flower, respectively. Participants' performance improved over time on the CANTAB Multitasking Test and Rapid Visual Information Processing test (both p-values <0.001). All other changes in cognitive performance measures over time were non-significant (p > 0.05). Vaporization of flower was associated with significantly stronger subjective feelings of 'stoned' and 'sedated' relative to oils (both p < 0.001).

CONCLUSIONS

These findings suggest that prescribed medical cannabis may have minimal acute impact on cognitive function among patients with chronic health conditions, although larger and controlled trials are needed.

The Place of Cannabinoids in the Treatment of Gynecological Pain

Cannabis sativa (L), a plant with an extensive history of medicinal usage across numerous cultures, has received increased attention over recent years for its therapeutic potential for gynecological disorders such as endometriosis, chronic pelvic pain, and primary dysmenorrhea, due at least in part to shortcomings with current management options. Despite this growing interest, cannabis inhabits an unusual position in the modern medical pharmacopoeia, being a legal medicine, legal recreational drug, and an illicit drug, depending on jurisdiction. To date, the majority of studies investigating cannabis use have found that most people are using illicit cannabis, with numerous obstacles to medical cannabis adoption having been identified, including outdated drug-driving laws, workplace drug testing policies, the cost of quality-assured medical cannabis products, a lack of cannabis education for healthcare professionals, and significant and persistent stigma. Although currently lacking robust clinical trial data, a growing evidence base of retrospective data, cohort studies, and surveys does support potential use in gynecological pain conditions, with most evidence focusing on endometriosis. Cannabis consumers report substantial reductions in pelvic pain, as well as common comorbid symptoms such as gastrointestinal disturbances, mood disorders such as anxiety and depression, and poor sleep. Substitution effects were reported, with >50% reduction or cessation in opioid and/or non-opioid analgesics being the most common. However, a substantial minority report not disclosing cannabis consumption to their health professional. Therefore, while such deprescribing trends are potentially beneficial, the importance of medical supervision during this process is paramount given the possibility for withdrawal symptoms.

Driving-related behaviors, attitudes, and perceptions among Australian medical cannabis users: results from the CAMS 20 survey

Road safety is an important concern amidst expanding worldwide access to legal cannabis. The present study reports on the driving-related subsection of the Cannabis as Medicine Survey 2020 (CAMS-20) which surveyed driving-related behaviors, attitudes, and perceptions among Australian medical cannabis (MC) users. Of the 1063 respondents who reported driving a motor vehicle in the past 12 months, 28% (297/1063) reported driving under the influence of cannabis (DUIC). Overall, 49-56% of respondents said they typically drive within 6 h of MC use, depending on the route of administration (oral or inhaled). Non-medical cannabis (NMC) was perceived to be more impairing for driving than MC. Binary logistic regression revealed associations between likelihood of DUIC and (1) inhaled routes of cannabis administration, (2) THC-dominant products, (3) illicit rather than prescribed use, (4) believing NMC does not impair driving, and (5) not being deterred by roadside drug testing. Overall, these findings suggest there is a relatively low perception of driving-related risk among MC users. Targeted education programs may be needed to highlight the potential risks associated with DUIC, and further research is needed to determine whether driving performance is differentially affected by MC and NMC.

Australian daily cannabis users' use of police avoidance strategies and compensatory behaviours to manage the risks of drug driving

INTRODUCTION

Daily use of cannabis is increasing in Australia, yet there is limited understanding of the driving behaviours within this cohort, including how they perceive and manage the risks of being apprehended for drug driving and involved in a crash after consumption.

METHODS

An online survey was completed by 487 Australians who reported daily cannabis use (30% medically prescribed patients, 58% male).

RESULTS

Current drug driving (i.e., driving within 4 h of consuming cannabis each week) was reported by 86% of participants. Future drug driving was anticipated by 92% of the sample. While most participants (93%) disagreed that their risk of crash increased following cannabis use, participants reported that they would drive more carefully (89%), leave greater headway (79%) and/or drive slower (51%) following cannabis consumption. Half of the sample (53%) perceived the risk of apprehension for drug driving to be likely to some extent. Strategies to reduce the likelihood of being detected were used by 25% of participants, and included using Facebook police location sites (16%), driving on back roads (6%) and/or consuming substances to mask the presence of drugs (13%). The regression analysis revealed that individuals who reported more occasions of cannabis use per day, and who perceived that cannabis does not reduce driving ability, reported a greater extent of current drug driving.

DISCUSSION AND CONCLUSIONS

Interventions and education which aim to challenge this perception that 'cannabis does not reduce driving ability' may prove important for reducing drug driving among the most frequent consumers of cannabis.

Tetrahydrocannabinol and Cannabidiol in Tourette Syndrome

BACKGROUND: Tourette syndrome is characterized by chronic motor and vocal tics. There is preliminary evidence of benefit from cannabis products containing Δ9-tetrahydrocannabinol (THC) and that coadministration of cannabidiol (CBD) improves the side-effect profile and safety. METHODS: In this double-blind, crossover trial, participants with severe Tourette syndrome were randomly assigned to a 6-week treatment period with escalating doses of an oral oil containing 5 mg/ml of THC and 5 mg/ml of CBD, followed by a 6-week course of placebo, or vice versa, separated by a 4-week washout period. The primary outcome was the total tic score on the Yale Global Tic Severity Scale (YGTSS; range, 0 to 50 [higher scores indicate greater severity of symptoms]). Secondary outcomes included video-based assessment of tics, global impairment, anxiety, depression, and obsessive-compulsive symptoms. Outcomes were correlated with plasma levels of cannabinoid metabolites. A computerized cognitive battery was administered at the beginning and the end of each treatment period. RESULTS: Overall, 22 participants (eight female participants) were enrolled. Reduction in total tic score (at week 6 relative to baseline) as measured by the YGTSS was 8.9 (±7.6) in the active group and 2.5 (±8.5) in the placebo group. In a linear mixed-effects model, there was a significant interaction of treatment (active/placebo) and visit number on tic score (coefficient = −2.28; 95% confidence interval, −3.96 to −0.60; P=0.008), indicating a greater decrease (improvement) in tics under active treatment. There was a correlation between plasma 11-carboxy-tetrahydrocannabinol levels and the primary outcome, which was attenuated after exclusion of an outlier. The most common adverse effect in the placebo period was headache (n=7); in the active treatment period, it was cognitive difficulties, including slowed mentation, memory lapses, and poor concentration (n=8). CONCLUSIONS: In severe Tourette syndrome, treatment with THC and CBD reduced tics and may reduce impairment due to tics, anxiety, and obsessive-compulsive disorder; although in some participants this was associated with slowed mentation, memory lapses, and poor concentration. (Funded by the Wesley Medical Research Institute, Brisbane, and the Lambert Initiative for Cannabinoid Therapeutics, a philanthropically-funded research organization at the University of Sydney, Australia; Australian and New Zealand Clinical Trials Registry number, ACTRN12618000545268.)

Balancing risks and benefits of cannabis use: umbrella review of meta-analyses of randomised controlled trials and observational studies

OBJECTIVE

To systematically assess credibility and certainty of associations between cannabis, cannabinoids, and cannabis based medicines and human health, from observational studies and randomised controlled trials (RCTs).

DESIGN

Umbrella review.

DATA SOURCES

PubMed, PsychInfo, Embase, up to 9 February 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Systematic reviews with meta-analyses of observational studies and RCTs that have reported on the efficacy and safety of cannabis, cannabinoids, or cannabis based medicines were included. Credibility was graded according to convincing, highly suggestive, suggestive, weak, or not significant (observational evidence), and by GRADE (Grading of Recommendations, Assessment, Development and Evaluations) (RCTs). Quality was assessed with AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2). Sensitivity analyses were conducted.

RESULTS

101 meta-analyses were included (observational=50, RCTs=51) (AMSTAR 2 high 33, moderate 31, low 32, or critically low 5). From RCTs supported by high to moderate certainty, cannabis based medicines increased adverse events related to the central nervous system (equivalent odds ratio 2.84 (95% confidence interval 2.16 to 3.73)), psychological effects (3.07 (1.79 to 5.26)), and vision (3.00 (1.79 to 5.03)) in people with mixed conditions (GRADE=high), improved nausea/vomit, pain, spasticity, but increased psychiatric, gastrointestinal adverse events, and somnolence among others (GRADE=moderate). Cannabidiol improved 50% reduction of seizures (0.59 (0.38 to 0.92)) and seizure events (0.59 (0.36 to 0.96)) (GRADE=high), but increased pneumonia, gastrointestinal adverse events, and somnolence (GRADE=moderate). For chronic pain, cannabis based medicines or cannabinoids reduced pain by 30% (0.59 (0.37 to 0.93), GRADE=high), across different conditions (n=7), but increased psychological distress. For epilepsy, cannabidiol increased risk of diarrhoea (2.25 (1.33 to 3.81)), had no effect on sleep disruption (GRADE=high), reduced seizures across different populations and measures (n=7), improved global impression (n=2), quality of life, and increased risk of somnolence (GRADE=moderate). In the general population, cannabis worsened positive psychotic symptoms (5.21 (3.36 to 8.01)) and total psychiatric symptoms (7.49 (5.31 to 10.42)) (GRADE=high), negative psychotic symptoms, and cognition (n=11) (GRADE=moderate). In healthy people, cannabinoids improved pain threshold (0.74 (0.59 to 0.91)), unpleasantness (0.60 (0.41 to 0.88)) (GRADE=high). For inflammatory bowel disease, cannabinoids improved quality of life (0.34 (0.22 to 0.53) (GRADE=high). For multiple sclerosis, cannabinoids improved spasticity, pain, but increased risk of dizziness, dry mouth, nausea, somnolence (GRADE=moderate). For cancer, cannabinoids improved sleep disruption, but had gastrointestinal adverse events (n=2) (GRADE=moderate). Cannabis based medicines, cannabis, and cannabinoids resulted in poor tolerability across various conditions (GRADE=moderate). Evidence was convincing from observational studies (main and sensitivity analyses) in pregnant women, small for gestational age (1.61 (1.41 to 1.83)), low birth weight (1.43 (1.27 to 1.62)); in drivers, car crash (1.27 (1.21 to 1.34)); and in the general population, psychosis (1.71 (1.47 to 2.00)). Harmful effects were noted for additional neonatal outcomes, outcomes related to car crash, outcomes in the general population including psychotic symptoms, suicide attempt, depression, and mania, and impaired cognition in healthy cannabis users (all suggestive to highly suggestive).

CONCLUSIONS

Convincing or converging evidence supports avoidance of cannabis during adolescence and early adulthood, in people prone to or with mental health disorders, in pregnancy and before and while driving. Cannabidiol is effective in people with epilepsy. Cannabis based medicines are effective in people with multiple sclerosis, chronic pain, inflammatory bowel disease, and in palliative medicine but not without adverse events.

STUDY REGISTRATION

PROSPERO CRD42018093045.

FUNDING

None.

Cannabinol (CBN; 30 and 300 mg) effects on sleep and next-day function in insomnia disorder ('CUPID' study): protocol for a randomised, double-blind, placebo-controlled, cross-over, three-arm, proof-of-concept trial

OBJECTIVE

Insomnia is the most prevalent sleep disorder, with few effective pharmacotherapies. Anecdotal reports and recent preclinical research suggest that cannabinol (CBN), a constituent of Cannabis sativa derived from delta-9-tetrahydrocannabinol, could be an effective treatment. Despite this, the isolated effects of CBN on sleep have yet to be systematically studied in humans.

METHODS

The present protocol paper describes a randomised, double-blind, placebo-controlled, single-dose, three-arm, cross-over, proof-of-concept study which investigates the effects of CBN on sleep and next-day function in 20 participants with clinician-diagnosed insomnia disorder and an Insomnia Severity Index Score ≥15. Participants receive a single fixed oral liquid dose of 30 mg CBN, 300 mg CBN and matched placebo, in random order on three treatment nights; each separated by a 2-week wash-out period. Participants undergo overnight sleep assessment using in-laboratory polysomnography and next-day neurobehavioural function tests. The primary outcome is wake after sleep onset minutes. Secondary outcomes include changes to traditional sleep staging, sleep-onset latency and absolute spectral power during non-rapid eye movement (NREM) sleep. Tertiary outcomes include changes to sleep spindles during NREM sleep, arousal indices, absolute spectral power during REM sleep and subjective sleep quality. Safety-related and exploratory outcomes include changes to next-day simulated driving performance, subjective mood and drug effects, postural sway, alertness and reaction time, overnight memory consolidation, pre and post-sleep subjective and objective sleepiness; and plasma, urinary, and salivary cannabinoid concentrations. The study will provide novel preliminary data on CBN efficacy and safety in insomnia disorder, which will inform larger clinical trials.

ETHICS AND DISSEMINATION

Human Research Ethics Committee approval has been granted by Bellberry (2021-08-907). Study findings will be disseminated in a peer-reviewed journal and at academic conferences.

TRIAL REGISTRATION NUMBER

NCT05344170.

Does the "Entourage Effect" in Cannabinoids Exist? A Narrative Scoping Review

Background: The concept of an "entourage" effect in the cannabis and cannabinoids' field was first introduced in the late 1990s, during a period when most research on medical cannabinoids focused on the effects of isolated cannabinoids, such as cannabidiol and Δ9-tetrahydrocannabinol. Over the past decade, however, with the increased understanding of the endocannabinoid system, the discovery of other phytocannabinoids and their potential therapeutic uses, the term has gained widespread use in scientific reviews and marketing campaigns. Objective: Critically review the application of the term "entourage effect (EE)" in the literature and its endorsement by certain sectors of the cannabis market. Also, explore the perspectives for further interpretation and elaboration of the term based on current evidence, aiming to contribute to a more nuanced understanding of the concept and its implications for cannabinoid-based medicine. Methods: A comprehensive review of the literature was conducted to evaluate the current state of knowledge regarding the entourage effect. Relevant studies and scientific reviews were analyzed to assess the evidence of clinical efficacy and safety, as well as the regulation of cannabinoid-containing product production. Results: The EE is now recognized as a synergistic phenomenon in which multiple components of cannabis interact to modulate the therapeutic actions of the plant. However, the literature provides limited evidence to support it as a stable and predictable phenomenon. Hence, there is also limited evidence to support clinical efficacy, safety, and appropriate regulation for cannabinoid-containing products based on a "entourage" hypothesis. Conclusion: The EE has significant implications for the medical use of cannabinoid-containing products and their prescription. Nevertheless, a critical evaluation of the term's application is necessary. Further research and evidence are needed to establish the clinical efficacy, safety, and regulatory framework for these products. It's crucial that regulators, the pharmaceutical industry, the media, and health care providers exercise caution and avoid prematurely promoting the entourage effect hypothesis as a scientific proven phenomenon for cannabinoids and other cannabis-derived compound combinations.

Driving Under the Influence of Cannabis: Impact of Combining Toxicology Testing with Field Sobriety Tests

BACKGROUND

Cannabis is increasingly used both medically and recreationally. With widespread use, there is growing concern about how to identify cannabis-impaired drivers.

METHODS

A placebo-controlled randomized double-blinded protocol was conducted to study the effects of cannabis on driving performance. One hundred ninety-one participants were randomized to smoke ad libitum a cannabis cigarette containing placebo or delta-9-tetrahydrocannabinol (THC) (5.9% or 13.4%). Blood, oral fluid (OF), and breath samples were collected along with longitudinal driving performance on a simulator (standard deviation of lateral position [SDLP] and car following [coherence]) over a 5-hour period. Law enforcement officers performed field sobriety tests (FSTs) to determine if participants were impaired.

RESULTS

There was no relationship between THC concentrations measured in blood, OF, or breath and SDLP or coherence at any of the timepoints studied (P > 0.05). FSTs were significant (P < 0.05) for classifying participants into the THC group vs the placebo group up to 188 minutes after smoking. Seventy-one minutes after smoking, FSTs classified 81% of the participants who received active drug as being impaired. However, 49% of participants who smoked placebo (controls) were also deemed impaired at this same timepoint. Combining a 2 ng/mL THC cutoff in OF with positive findings on FSTs reduced the number of controls classified as impaired to zero, 86 minutes after smoking the placebo.

CONCLUSIONS

Requiring a positive toxicology result in addition to the FST observations substantially improved the classification accuracy regarding possible driving under the influence of THC by decreasing the percentage of controls classified as impaired.

Challenges and considerations for treating PTSD with medicinal cannabis: the Australian clinician's perspective

INTRODUCTION

Preclinical and experimental research have provided promising evidence that medicinal cannabis may be efficacious in the treatment of posttraumatic stress disorder (PTSD). However, implementation of medicinal cannabis into routine clinical therapies may not be straightforward.

AREAS COVERED

In this review, we describe some of the clinical, practical, and safety challenges that must be addressed for cannabis-based treatment of PTSD to be feasible in a real-world setting. These issues are especially prevalent if medicinal cannabis is to be combined with trauma-focused psychotherapy.

EXPERT OPINION

Future consideration of the clinical and practical considerations of cannabis use in PTSD therapy will be essential to both the efficacy and safety of the treatment protocols that are being developed. These issues include dose timing and titration, potential for addiction, product formulation, windows of intervention, and route of administration. In particular, exposure therapy for PTSD involves recall of intense emotions, and the interaction between cannabis use and reliving of trauma memories must be explored in terms of patient safety and impact on therapeutic outcomes.

"Wake-and-bake" cannabis use: Predictors and cannabis-related outcomes of use shortly after waking

BACKGROUND

Given recent historical increases in young adults frequent cannabis use and changes in cannabis policies throughout the United States, there is a need to examine high-risk patterns of use. This paper examined predictors and cannabis-related outcomes of "wake-and-bake" cannabis use, operationalized as use within 30min of waking.

METHODS

Participants were 409 young adults (Mage=21.61 years, 50.8% female) enrolled in a longitudinal study on simultaneous alcohol and cannabis use (i.e., using alcohol and cannabis at the same time such that their effects overlap). Eligibility criteria included reporting alcohol use 3+ times and simultaneous alcohol and cannabis use 1+ times in the past month. Participants completed twice-daily surveys for six 14-day bursts across two calendar years. Aims were tested using multilevel models.

RESULTS

Analyses were limited to cannabis use days (9406 days; 33.3% of all sampled days), and thereby to participants who reported using cannabis (384 participants; 93.9% of the sample). Wake-and-bake use was reported on 11.2% of cannabis use days and at least once by 35.4% of participants who used cannabis. On wake-and-bake use days, participants were high for more hours and had greater odds of driving under the influence of cannabis, but did not experience more negative consequences, relative to non-wake-and-bake cannabis use days. Participants who reported more cannabis use disorder symptoms and those reporting higher average social anxiety motives for cannabis use reported more frequent wake-and-bake use.

CONCLUSIONS

Wake-and-bake cannabis use may be a useful marker of high-risk cannabis use, including driving under the influence of cannabis.

Measuring the diversity gap of cannabis clinical trial participants compared to people who report using cannabis

Little is known about the demographics of people who use cannabis, including how use trends within population subgroups have evolved over time. It is therefore challenging to know if the demographics of participants enrolled in cannabis clinical trials are representative of those who use cannabis. To fill this knowledge gap, data from the National Survey on Drug Use and Health (NSDUH) on "past-month" cannabis use across various population subgroups in the United States was examined from 2002 to 2021. The most notable increases in "past-month" cannabis use prevalence occurred in those aged 65 and older (2,066.1%) and 50-64-year-olds (472.4%). In 2021, people reporting "past-month" cannabis use were 56.6% male and 43.4% female. Distribution across self-reported race and ethnicity was 64.1% White, 14.3% Black, 14.1% Hispanic, and 3.1% more than one race. And many ages were represented as 24.4% were 26-34, 24.1% were 35-49, 22.4% were 18-25, and 17.6% were 50-64 years old. To understand if these population subgroups are represented in cannabis clinical trials, participant demographics were extracted from peer-reviewed clinical trials reporting on pharmacokinetic and/or pharmacodynamic models of cannabis or cannabinoids. Literature was grouped by publication year (2000-2014 and 2015-2022) and participant prior exposure to cannabis. Results identified that cannabis clinical trial participants are skewed toward overrepresentation by White males in their 20s and 30s. This represents structural discrimination in the research landscape that perpetuates social and health inequities.

Preliminary study of the interactive effects of THC and ethanol on self-reported ability and simulated driving, subjective effects, and cardiovascular responses

RATIONALE

Drug- and alcohol-related motor vehicle accidents are a leading cause of morbidity and mortality worldwide. Compared to alcohol, less is known about the effects of cannabis on driving and even less about their combined effects.

OBJECTIVE

To characterize the combined and separate effects of ethanol and tetrahydrocannabinol (THC) on perceived ability to drive, subjective effects, and simulated driving.

METHODS

In a within-subject (crossover), randomized, placebo-controlled, double-blind, 2 × 2 design, the effects of oral THC (10 mg [dronabinol] or placebo) and low-dose intravenous ethanol (clamped at BAC 0.04% or placebo) on perceived ability to drive, simulated driving (standard deviation of lateral position [SDLP]), subjective effects (e.g., "high"), and physiological effects (e.g., heart rate) were studied in healthy humans (n = 18).

RESULTS

Subjects reported reductions in perceived ability to drive (THC < ethanol < combination) which persisted for ~ 6 h (placebo = ethanol, THC < combination). Ethanol and THC produced synergistic effects on heart rate, significant differences compared to either drug alone on perceived ability to drive and feeling states of intoxication (e.g., high), as well increases in SDLP compared to placebo.

CONCLUSIONS

Perceived ability to drive is reduced under the influence of THC against the backdrop of blood alcohol levels that are below the legal limit. People should be aware that the effects of oral THC on driving may persist for up to six hours from administration. Findings are relevant to the increasingly common practice of combining alcohol and cannabinoids and the effects on driving.

Blood cannabinoid molar metabolite ratios are superior to blood THC as an indicator of recent cannabis smoking

INTRODUCTION

Cannabis use is a growing concern in transportation and workplace incidents. Because Δ9-tetrahydrocannabinol is detectable after acute psychoactive effects have resolved, it has limitations as an indicator of recent usage or potential impairment.

METHODS

In an observational study of driving and psychomotor performance, we measured whole blood Δ9-tetrahydrocannabinol plus its metabolites 11-hydroxy-Δ9-tetrahydrocannabinol and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol by liquid chromatography with tandem mass spectrometry at baseline and 30 min after starting a 15-minute interval of smoking cannabis in 24 occasional and 32 daily cannabis smokers. We calculated two blood cannabinoid molar metabolite ratios: 1) [Δ9-tetrahydrocannabinol] to [11-nor-9-carboxy-Δ9-tetrahydrocannabinol] and 2) ([Δ9-tetrahydrocannabinol] + [11-hydroxy-Δ9-tetrahydrocannabinol]) to [11-nor-9-carboxy-Δ9-tetrahydrocannabinol]. We compared these to blood [Δ9-tetrahydrocannabinol] alone as indicators of recent cannabis smoking.

RESULTS

Median Δ9-tetrahydrocannabinol concentrations increased from 0 ( 0.38). By comparison, a cut-point for Δ9-tetrahydrocannabinol of 5.3 µg/L yielded 88% specificity, 73% sensitivity, and 80% accuracy.

CONCLUSIONS

In occasional and daily users, the blood cannabinoid molar metabolite ratios were superior to whole blood Δ9-tetrahydrocannabinol as indicators of recent cannabis smoking. We recommend measurement and reporting of Δ9-tetrahydrocannabinol, 11-hydroxy-Δ9-tetrahydrocannabinol, and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol, and their molar metabolite ratios in forensic and safety investigations.

Cannabis use and gastrointestinal tract illnesses: The National Health and Nutrition Examination Surveys, 2005-2018

INTRODUCTION

The antiemetic properties of cannabis have motivated its use in the management of chemotherapy-induced nausea and vomiting. Conversely, case reports of intractable vomiting among heavy cannabis users have increasingly appeared in the literature. Studies on cannabis and gastrointestinal tract (GIT) health are scare. Here, we use data for the National Health and Nutrition Examination Surveys (NHANES, 2005-2018) to estimate the association between cannabis use and GIT illness.

METHODS

The study sample included non-pregnant adult NHANES participants (20-59 years) without history of cancer or HIV (n = 18,753). Cannabis use was categorised into never, former (0 day in the past 30 days), infrequent (1-2 days), occasional (3-19 days) and frequent (20-30 days) use. Recent GIT illness was defined as experiencing GIT illness with vomiting or diarrhoea that started in the 30 days prior to NHANES. Logistic regression was used to regress GIT illness on cannabis use, adjusting for potential confounders.

RESULTS

Compared to never use, frequent cannabis use was associated with higher odds of GIT illness (OR = 1.4; 95% confidence interval 1.04, 1.9). There were no associations between former, infrequent or occasional cannabis use and GIT illness.

DISCUSSION AND CONCLUSIONS

Frequent cannabis use is associated with GIT illnesses in a large cross-sectional study of US residents. It is possible that frequent cannabis use adversely affects GIT health, consistent with clinical case reports. Alternatively, patients with GIT illness might self-medicate with cannabis given its antiemetic properties. Prospective studies are needed to understand the effects of cannabis use on GIT health.

The minor cannabinoid cannabigerol (CBG) is a highly specific blood biomarker of recent cannabis smoking

INTRODUCTION

The determination of recent cannabis use is of forensic interest in the investigation of automotive crashes, workplace incidents and other mishaps. Because Δ9-tetrahydrocannabinol may persist in blood after psychoactive effects of intoxication resolve, particularly in regular users, short-lived minor cannabinoids such as cannabigerol have merited examination as adjunct indicators of recent cannabis inhalation.

METHODS

As part of an observational cohort study, whole blood cannabinoids including cannabigerol were measured in whole blood by liquid chromatography with tandem mass spectrometry at baseline, and 30 minutes after initiation of a 15-minute supervised interval of ad libitum cannabis smoking in occasional (1-2 days/week over the past 30 days) (n = 24) and daily cannabis smokers (n = 32). Per protocol, subjects self-reported abstention from inhaling cannabis (>8 h) or ingesting cannabis (>12 h) prior to baseline measurement.

RESULTS

At baseline, none of the occasional users had detectable cannabigerol (limit of detection = 0.2 µg/L), whereas cannabigerol was detectable post-smoking in 7 of 24 (29%). Among daily cannabis users, 2 of 32 (6%) had detectable cannabigerol at baseline, increasing to 21 of 32 (66%) post-smoking. The odds ratio for recent cannabis smoking associated with a detectable cannabigerol was 27 (95% confidence interval: 6.6, 110.3). In this mixed cohort of occasional and daily cannabis users, receiver operator characteristic curve analysis indicated that whole blood cannabigerol concentration of ≥ 0.2 µg/L had 96% specificity, 50% sensitivity, and 73% accuracy for identifying a 15-minute interval of ad libitum cannabis smoking initiated 30 minutes earlier. Post smoking blood Δ9-tetrahydrocannabinol (median = 5.6 µg/L in occasional users, 21.3 µg/L in daily users) was significantly correlated with post-smoking cannabigerol (P < 0.0001).

CONCLUSION

Whole blood cannabigerol may have forensic utility as a highly specific albeit insensitive biomarker of recent cannabis smoking.

Trends in emergency department visits associated with cannabis use among older adults in California, 2005-2019

BACKGROUND

The use of cannabis among older adults is increasing in the United States. While cannabis use has been suggested to help alleviate chronic symptoms experienced by older adults, its potential adverse effects may lead to unintended consequences, including increased acute healthcare utilization related to its use. The objective of this study was to examine trends in cannabis-related emergency department (ED) visits in California.

METHODS

Using data from the Department of Healthcare Access and Information, we conducted a trend analysis of cannabis-related ED visits from all acute care hospitals in California from 2005 to 2019. For each calendar year, we determined the cannabis-related ED visit rate per 100,000 ED visits for adults aged ≥65 utilizing primary or secondary diagnosis codes. We estimated the absolute and relative changes in overall cannabis-related visit rates during the study period and by subgroup, including age (65-74, 75-84, ≥85), race/ethnicity, sex, payer/insurance, Charlson comorbidity index score, and cannabis-related diagnosis code.

RESULTS

The cannabis-related ED visit rate increased significantly for adults aged ≥65 and all subgroups (p < 0.001). The overall rate increased from 20.7 per 100,000 visits in 2005 to 395.0 per 100,000 ED visits in 2019, a 1804% relative increase. By race/ethnicity, older Black adults had the highest ED visit rate in 2019 and the largest absolute increase while older males had a higher ED visit rate in 2019 and a greater absolute increase than older women. Older adults with a higher Charlson score had a higher ED visit rate in 2019 and a larger absolute increase during the study period.

CONCLUSION

Cannabis-related ED visits are increasing among older adults in California and are an adverse effect of cannabis use. Asking about cannabis use and providing education about its use should be a part of routine medical care for older adults.

Associations of cannabis use with motor vehicle crashes and traffic stops among older drivers: AAA LongROAD study

BACKGROUND

Acute cannabis use is associated with a higher risk of motor vehicle crashes (MVC). This study aimed to determine if self-reported past-year cannabis use is associated with MVC or traffic stops among older drivers.

METHODS

This cross-sectional analysis used data from a multi-center study enrolling active drivers aged 65-79 years. Data regarding cannabis use, MVC, and traffic stops (i.e., being pulled over by police, whether ticketed or not) within the previous 12 months were collected through participant interviews. Log-binomial regression models examined associations of past-year cannabis use with MVC and traffic stops, adjusting for site and sociodemographic and mental health characteristics.

RESULTS

Of 2,095 participating older drivers, 186 (8.88%) used cannabis in the past year but only 10 (<0.5%) within an hour before driving in the last 30 days; 11.41% reported an MVC and 9.45% reported a traffic stop. Past-year cannabis users had a higher prevalence of MVC (adjusted prevalence ratio [aPR] = 1.38; 95%CI: 0.96, 2.00; p = 0.086) and traffic stops (aPR = 1.58; 1.06, 2.35; p = 0.024).

CONCLUSIONS

Past-year cannabis use was associated with increased traffic stops, which are correlated modestly with increased MVC in past studies and may indicate impaired driving performance. We did not find a statistically significant association of past-year cannabis use with MVC, which may indicate limited sustained effects on driving performance from periodic use among older adults, who report rarely driving immediately after use.

ASRA Pain Medicine consensus guidelines on the management of the perioperative patient on cannabis and cannabinoids

BACKGROUND

The past two decades have seen an increase in cannabis use due to both regulatory changes and an interest in potential therapeutic effects of the substance, yet many aspects of the substance and their health implications remain controversial or unclear.

METHODS

In November 2020, the American Society of Regional Anesthesia and Pain Medicine charged the Cannabis Working Group to develop guidelines for the perioperative use of cannabis. The Perioperative Use of Cannabis and Cannabinoids Guidelines Committee was charged with drafting responses to the nine key questions using a modified Delphi method with the overall goal of producing a document focused on the safe management of surgical patients using cannabinoids. A consensus recommendation required ≥75% agreement.

RESULTS

Nine questions were selected, with 100% consensus achieved on third-round voting. Topics addressed included perioperative screening, postponement of elective surgery, concomitant use of opioid and cannabis perioperatively, implications for parturients, adjustment in anesthetic and analgesics intraoperatively, postoperative monitoring, cannabis use disorder, and postoperative concerns. Surgical patients using cannabinoids are at potential increased risk for negative perioperative outcomes.

CONCLUSIONS

Specific clinical recommendations for perioperative management of cannabis and cannabinoids were successfully created.

Crash-involved THC-positive drivers in Norway have a high frequency of polysubstance use

BACKGROUND

Tetrahydrocannabinol (THC) is the most frequently detected drug in blood samples from apprehended drug driving suspects in Norway. This investigation aimed to study the extent of polysubstance use among apprehended crash-involved drivers with THC concentrations above the legal limit and explore the importance of THC in polysubstance cases.

METHODS

We selected all drug driving cases where blood samples had been submitted for forensic toxicology testing after involvement in road traffic crashes during 2013-2020, except drivers who were fatally injured.

RESULTS

Twenty percent (n = 2133) of the 10,520 apprehended crash-involved drivers had concentrations of THC in their blood above the legal limit of 1.3 ng/mL, and 84 % of those also had concentrations of alcohol or other drugs above the legal limits; 61 % for sedatives, 38 % for stimulants, 33 % for alcohol, and 10 % for opioids. The most frequent substance combination was cannabis together with sedatives and stimulants (22.9 %; n = 488). Polysubstance use was least common among drivers under 24 years. The proportion of drivers with THC > 5 ng/mL was highest if the blood sample was collected within 90 min after the crash, and when only THC was detected. There was a statistically significant inverse association between THC > 5 ng/mL and concentrations of alcohol or amphetamines at the highest sanction level.

CONCLUSIONS

Most apprehended crash-involved THC-positive drivers also tested positive for other psychoactive substances. Drivers with high blood THC concentrations had less often high concentrations of other substances; cannabis might then have been a more important contributor to impairment.

The "Next Day" Effects of Cannabis Use: A Systematic Review

Background: Δ⁹-Tetrahydrocannabinol (THC), the main intoxicating component of cannabis, can cause cognitive and psychomotor impairment. Whether this impairment is still present many hours or even days after THC use requires clarification. Possible "next day" effects are of major significance in safety-sensitive workplaces. We therefore conducted a systematic review of studies investigating the "next day" effects of THC. Methods: Studies that measured performance on safety-sensitive tasks (e.g., driving, flying) and/or neuropsychological tests >8 h after THC (or cannabis) use using interventional designs were identified by searching two online databases from inception until March 28, 2022. Risk of bias (RoB) was evaluated using the relevant Cochrane tools. Results were described in terms of whether THC had a significant effect on performance relative to the primary comparator (i.e., placebo or baseline, as appropriate). Results: Twenty studies (n=458) involving 345 performance tests were reviewed. Most studies administered a single dose of THC (median [interquartile range]: 16 [11-26] mg) and assessed performance between >12 and 24 h post-treatment. N=209/345 tests conducted across 16 published studies showed no "next day" effects of THC. Nine of these 16 studies used randomized, double-blind, placebo-controlled designs. Half (N=8) had "some" RoB, and half (N=8) had a "high" RoB. Notably, N=88 of these 209 tests failed to demonstrate "acute" (i.e., <8 h post-treatment) THC-induced impairment. N=12/345 tests conducted across five published studies indicated negative (i.e., impairing) "next day" effects of THC. None of these five studies used randomized, double-blind, placebo-controlled designs and all were published >18 years ago (four, >30 years ago). Three had "some" RoB, and two had a "high" RoB. A further N=121/345 tests indicated "unclear" "next day" effects of THC with insufficient information provided to assess outcomes. The remaining N=3/345 tests indicated positive (i.e., enhancing) "next day" effects of THC. Conclusions: Some lower quality studies have reported "next day" effects of THC on cognitive function and safety-sensitive tasks. However, most studies, including some of higher quality, have found no such effect. Overall, it appears that there is limited scientific evidence to support the assertion that cannabis use impairs "next day" performance. Further studies involving improved methodologies are required to better address this issue.

Can cannabis kill? Characteristics of deaths following cannabis use in England (1998-2020)

BACKGROUND

Cannabis is the most widely used illegal drug but is rarely considered a causal factor in death.

AIMS

This study aimed to understand trends in deaths in England where cannabinoids were detected at post-mortem, and to evaluate the clinical utility of post-mortem cannabinoid concentrations in coronial investigations.

METHODS

Deaths with cannabinoid detections reported to the National Programme on Substance Abuse Deaths (NPSAD) were extracted and analysed.

RESULTS

From 1998 to 2011, on average 7% of all cases reported to NPSAD had a cannabinoid detected (n = 110 deaths per year), rising to 18% in 2020 (n = 350). Death following cannabis use alone was rare (4% of cases, n = 136/3455). Traumatic injury was the prevalent underlying cause in these cases (62%, n = 84/136), with cannabis toxicity cited in a single case. Polydrug use was evident in most cases (96%, n = 3319/3455), with acute drug toxicity the prevalent underlying cause (74%, n = 2458/3319). Cardiac complications were the most cited physiological underlying cause of death (4%, n = 144/3455). The median average Δ9-tetrahydrocannabinol post-mortem blood concentrations were several magnitudes lower than previously reported median blood concentrations in living users (cannabis alone: 4.3 µg/L; cannabis in combination with other drugs: 3.5 µg/L).

CONCLUSIONS

Risk of death due to cannabis toxicity is negligible. However, cannabis can prove fatal in circumstances with risk of traumatic physical injury, or in individuals with cardiac pathophysiologies. These indirect harms need careful consideration and further study to better elucidate the role cannabis plays in drug-related mortality. Furthermore, the relevance of cannabinoid quantifications in determining cause of death in coronial investigations is limited.

A study of self-reported personal cannabis use and state legal status and associations with engagement in and perceptions of cannabis-impaired driving

Objective: The objectives of the current study were to (1) characterize predictors of perceived risk of driving within 2 h of cannabis use and driving after cannabis use in a sample of adults who have used cannabis in the past year and (2) determine whether the influence of these predictors vary by state legalizations status.Methods: Data for this study were from online surveys. Study participants from Colorado, Iowa, and Illinois were included if they reported being between 25 and 40 years old and had a history of cannabis use. Outcome variables included (1) days of cannabis use per month, (2) reported driving within 2 h of cannabis use (vs. not driving within 2 h as reference), (3) proportion of driving after cannabis use days per month (days of driving a car within 2 h of cannabis use per month/days of cannabis use per month), and (4) perception of safety of driving after cannabis use. Potential predictors included age of first use of cannabis, gender, education status, and state of residence. The SAS GLMSELECT Procedure was used for the analysis.Results: Increased age of first use of cannabis was associated with decreased days of cannabis use per month (B = -0.51 days/month per year), a reduction in the proportion of driving after cannabis use days per month (B = -0.02 per month), and decreased perception of safety of driving after cannabis use (B = -0.06 per year). Female gender was also associated with less use (B = -2.3 days per month), a lower proportion of driving following use (B = -0.06 days driving/days used), and decreased perception of safety (B = -0.29). In addition, residents of Colorado reported using the most days, had the highest likelihood of driving within 2 h of use, and had the most positive perceptions of being able to safely drive after cannabis use.Conclusions: The delay in onset of cannabis use may mitigate its use among adults and driving after cannabis use. This has important implications for driver safety. Intervention programs for reducing cannabis's effects on driving should focus on individuals with early onset of use, male drivers, and drivers in states where cannabis for adult recreational use is legalized.

Effects of psychotropic drugs on ocular parameters relevant to traffic safety: A systematic review

Driving is a complex neurobehavioural task necessitating the rapid selection, uptake, and processing of visual information. Eye movements that are critical for the execution of visually guided behaviour such as driving are also sensitive to the effects of psychotropic substances. The Embase (via Ovid), EBSCOHost, Psynet, Pubmed, Scopus and Web of Science databases were examined from January 01st, 2000 to December 31st, 2021. Study selection, data extraction and Cochrane Risk of Bias (RoB2) assessments were conducted according to PRISMA guidelines. The review was prospectively registered (CRD42021267554). In total, 36 full-text articles examined the effects of six principal psychotropic drug classes on measures of oculomotor parameters relevant to driving. Centrally depressing substances affect oculomotor responses in a dose-dependent manner. Psychostimulants improve maximal speed, but not accuracy, of visual search behaviours. Inhaled Δ-9-tetrahydrocannabinol (THC) increases inattention (saccadic inaccuracy) but does not consistently affect other oculomotor parameters. Alterations to composite ocular parameters due to psychoactive substance usage likely differently compromises performance precision during driving through impaired ability to select and process dynamic visual information.

Daily level predictors of impaired driving behaviors in young adults: Protocol design for utilizing daily assessments

Background

Motor vehicle crashes remain a leading cause of death among young adults (ages 18–25) in the United States. Many drivers implicated in these crashes are under the influence of alcohol, cannabis, or the simultaneous use of alcohol and cannabis. Extremely limited research has assessed impaired driving behaviors and their predictors at the daily level. Perceived norms and motives to use substances have empirical support suggesting they may impact impaired driving-related behavior. Novel approaches to assess these associations at the daily level are needed and may inform future intervention and prevention programs.

Objective

The goal of the current study is to utilize electronic daily assessments to assess driving under the influence of alcohol, cannabis, or simultaneous use and riding with a driver impaired by these substances to assess variability and predictors of these impaired driving-related behaviors at the daily level. This present manuscript details a protocol, measures, and a plan of analyses to assess how within-person differences in perceived norms and motives to use are associated with the likelihood of engaging in impaired driving-related behaviors.

Methods

Participants include young adults in Washington State who report simultaneous use in the past month and either driving under the influence of alcohol, cannabis, or simultaneous use, or riding with a driver under the influence of both substances in the past 6 months. Individuals who verify their identity and meet eligibility requirements will complete a baseline assessment after which they will be scheduled for training on the daily assessment procedure via Zoom. Next, they will be invited to complete daily surveys on Thursday, Friday, Saturday, and Sunday every other week for 6 months and a 6-month follow up assessment. Analyses will utilize multilevel models with days nested within individuals.

Results

The study is currently recruiting participants. A total of 192 participants have been recruited and 100 have completed the study protocol. Data collection is expected to be completed in Fall 2022.

Conclusions

This study utilizes a novel design to assess impaired driving and predictors at the daily level among young adults at high risk of impaired driving-related behaviors. Findings will provide unique data that will shape the knowledge base in the field of social science and public health substance use research and that may be helpful for future prevention and intervention efforts on impaired driving.

DRUG-IMPAIRED DRIVING AND TRAFFIC COLLISIONS: STUDY ON A CROSS SECTION OF THE ITALIAN POPULATION

The present study focuses on the association between road accidents and the presence of drugs of abuse markers in the biological fluids of the drivers. Biological fluids collected from 1,236 drivers involved in road accidents (54 fatal and 1,182 non-fatal crashes) in the Rome area were analysed for alcohol and psychotropic drugs, as required by judicial authorities. The substance most frequently detected was alcohol (in 19% of non-fatal and 32% of fatal crashes), followed by cannabinoids (12% of non-fatal crashes) and cocaine (9% of non-fatal and 20% of fatal crashes). The results obtained for cocaine and cannabinoids in blood and urine were compared. We observed the absence or low concentrations of the active drug in blood (cocaine was often below 5 ng/mL and THC below 1 ng/mL), whereas urinary concentrations of metabolites were generally high (benzoylecgonine 250 - above 5000 ng/mL, THCCOOH 15-270 ng/mL). The risk of being involved in a road accident if cocaine or cannabis markers were present in the urine specimens was evaluated compared to a control population. The odds ratios calculated, being 8.13 for cannabis and 5.32 for cocaine, suggest a strong association between the presence of these drugs in the urine of drivers and traffic accidents, regardless of their presence in blood samples. The present data suggest that the chance of being involved in a road accident is higher than in the control population even if the subject is no longer "under the influence" of cannabis or cocaine at the time of the accident.

The effects of oral and vaporized cannabis alone, and in combination with alcohol, on driving performance using the STISIM driving simulator: A two-part, double-blind, double-dummy, placebo-controlled, randomized crossover clinical laboratory protocol

The legalization of cannabis for medicinal and non-medicinal purposes, and the corresponding increase in diversity of cannabis products, has resulted an urgent need for cannabis regulatory science. Among the most pressing needs is research related to impairment due to cannabis exposure, especially on driving performance. The present project was designed to evaluate the impact of oral and vaporized cannabis, when administered alone or in combination with alcohol, on simulated driving performance (STISIM driving simulator), cognitive/psychomotor ability, and field sobriety performance. Healthy adults will complete two, double-blind, double-dummy, placebo-controlled, randomized crossover clinical laboratory studies, one with oral cannabis (16 men/16 women) and the second with vaporized cannabis (16 men/16 women). In each study, participants will complete seven experimental sessions during which acute doses of placebo or high Δ9-THC cannabis containing 0, 10, or 25 mg Δ9-THC will be administered both alone and in combination with placebo or alcohol-containing beverages (target breath alcohol concentrations, BAC, of 0.0% or 0.05%). A positive control session (i.e., alcohol at target BAC of 0.08% with placebo cannabis) will also be completed. Simulated driving performance tests (available for download; see Methods), field sobriety assessments, subjective drug effect questionnaires, a mobile device impairment test (DRUID app), and collection of whole blood specimens will be completed repeatedly during each session. Linear mixed models will be used to test for differences across experimental conditions and a priori planned comparisons will be used to determine differences between conditions of interest (e.g., cannabis alone vs cannabis with alcohol). This research is designed to extend prior studies of cannabis and alcohol on driving performance by using oral and vaporized routes of cannabis administration. By increasing understanding of impairment associated with co-use of alcohol and these novel forms of cannabis, this research could inform impairment detection standards for cannabis and alcohol and have important implications for law enforcement, public policy decisions regarding accessibility of these substances, and education of the general population who may use cannabis and/or alcohol. Lastly, this manuscript provides interested researchers with access to the simulated driving scenarios and data extraction tools developed for this study as a means of facilitating future cross-study comparisons, which is important given the heterogeneity in methods used across laboratories in prior research.

Separate and combined effects of alcohol and cannabis on mood, subjective experience, cognition and psychomotor performance: A randomized trial

Co-use of alcohol and cannabis is associated with increased frequency and intensity of use and related problems. This study examined acute effects of alcohol and cannabis on mood, subjective experience, cognition, and psychomotor performance. Twenty-eight healthy cannabis users aged 19-29 years with recent history of binge drinking completed this within-subjects, double-blind, double-dummy, placebo-controlled, randomized clinical trial. Participants received: placebo alcohol and placebo cannabis (<0.1% THC); alcohol (target breath alcohol content [BrAC] 80 mg/dL) and placebo cannabis; placebo alcohol and active cannabis (12.5% THC); and active alcohol and cannabis over four sessions. Profile of Mood States (POMS), Addiction Research Centre Inventory (ARCI), verbal free recall (VFR), Digit Symbol Substitution Test (DSST), Continuous Performance Test (CPT), and grooved pegboard (GPB) task were administered before and approximately 75 min after drinking alcohol (1 h after smoking cannabis ad libitum). Significant effects of condition were found for the POMS (Tension-Anxiety, Confusion) and ARCI (MBG, LSD, PCAG, Euphoria, Sedation), predominantly with greater increases emerging after cannabis or alcohol-cannabis combined relative to placebo. Significant effects were found for VFR (immediate total and delayed recall, percent retained), DSST (trials attempted, trials correct, reaction time), and GPB (non-dominant hand) predominantly with greater declines in performance after alcohol and alcohol-cannabis combined relative to placebo and/or cannabis. Cannabis appeared to affect mood and subjective experience, with minimal impact on cognitive performance. Alcohol appeared to impair cognitive and psychomotor performance, with minimal impact on mood and subjective experience. Acute effects of alcohol and cannabis combined were additive at most.

A cross-sectional survey: Exploring future healthcare workers' intention to use cannabis through extended theory of planned behavior

Cannabis is the most extensively abused drug, leading to multiple health burdens such as traffic accidents and psychosis. There is a global wave of legalization of recreational and medical cannabis. This study aimed to understand future healthcare workers' intention to use cannabis through extended Theory of Planned Behavior (TPB). An online cross-sectional survey on cannabis, including validated survey tools and questions on demographics, knowledge, and constructs of the TPB was designed, and distributed during virtual classes in late 2020. Responses were obtained from the Faculty of Medicine of a local university. Nine hundred ninety-six responses were collected, of which 629 were complete and analysed. Age was the only demographic variable associated with cannabis use intention (p = 0.029). Respondents with intention had better knowledge of cannabis. All TPB and additional constructs, including perceived behavioral control (COR = 3.44, 95% CI 2.72-4.35, p < 0.001), descriptive norm (COR = 2.24, 95% CI 1.81-2.77, p < 0.001), injunctive norm (COR = 0.51, 95% CI 0.42-0.61, p < 0.001), attitude (COR = 1.23, 95% CI 1.18-1.28, p < 0.001), knowledge (COR = 1.08, 95% CI 1.03-1.14), and perceived availability (COR = 2.75, 95% CI 2.22-3.40, p < 0.001) were individually associated with intention. In the final multiple logistic regression model adjusted for age, only attitude (AOR = 1.19, 95% CI 1.13-1.25, p < 0.001) and perceived availability (p = 0.004) showed statistically significant associations with intention. Descriptive norm (standardized coefficient = 0.570) had better explanatory power than the injunctive norm (standardized coefficient = -0.143) in the model. Perceived behavioral control was associated with intention among respondents with negative to neutral attitudes towards cannabis (AOR = 2.48, 95% CI 1.63-3.77, p < 0.001), but not among those with positive attitudes. All TPB constructs positively correlated with the intention to use cannabis. Changing the attitudes and perceived control on cannabis use may be useful in preventing cannabis use.

Cannabinoids, Insomnia, and Other Sleep Disorders

Sleep disturbances are often cited as a primary reason for medicinal cannabis use, and there is increasing clinical interest in the therapeutic potential of cannabinoids in treating sleep disorders. Burgeoning evidence suggests a role of the endocannabinoid system in regulating the circadian sleep-wake cycle, highlighting a potential avenue for developing novel therapeutics. Despite widespread use of cannabis products as sleep aids globally, robustly designed studies verifying efficacy in sleep-disordered populations are limited. Although some study outcomes have suggested cannabinoid utility in insomnia disorder and sleep apnea, most studies to date are limited by small sample sizes, lack of rigorously controlled study designs, and high risk of bias. This critical review summarizes the current evidence for the use of cannabinoids as a treatment for sleep disorders and provides an overview of endocannabinoid modulation of sleep-wake cycles, as well as the sleep-modulating effects of plant-derived cannabinoids such as delta-9-tetrahydrocannbinol, cannabidiol, and cannabinol. The review also discusses practical considerations for clinicians regarding cannabinoid formulations, routes of administration, respiratory concerns, dosing, potential side effects, drug interactions, and effects relevant to driving, tolerance, and withdrawal. Although current interest in, and uptake of, medicinal cannabis use for sleep disorders may have surpassed the evidence base, there is a strong rationale for continued investigation into the therapeutic potential of cannabinoids.

Evidence on the acute and residual neurocognitive effects of cannabis use in adolescents and adults: a systematic meta-review of meta-analyses

BACKGROUND

Cannabis is among the most consumed psychoactive substances world-wide. Considering changing policy trends regarding the substance, it is crucial to understand more clearly its potential acute and residual adverse effects from a public health viewpoint. Cognitive function is one of the targeted areas with conflicting findings. This meta-review measured the magnitude of acute and residual effects of cannabis on cognition in adolescents and adults provided by meta-analyses and evaluated quality of evidence.

METHODS

A systematic search was performed in PubMed, PsycINFO, Web of Science and Google Scholar. Meta-analyses were included if they quantitatively examined the performances of users from the general population on cognitive tasks.

RESULTS

The search retrieved 10 eligible meta-analyses (71 effects sizes, n = 43 761) with evidence ranging from low to moderate quality, which were categorized into domains of cognitive functions: executive functions (k = 7), learning and memory (k = 5), attention (k = 4), processing speed (k = 5), perceptual motor function (k = 2) and language (k = 2). Verbal learning and memory displayed the most robust evidence and were most impaired by acute cannabis intoxication that persisted after intoxication passed. Small-to-moderate acute and residual   adverse effects were reported for executive functioning. Cannabis use led to small deficits in inhibitory processes and flexibility, whereas small-to-moderate deficits were reported for working memory and decision-making. Evidence regarding processing speed and attention has shown that cannabis administration induced small-to-moderate adverse effects and residual neurocognitive deficits were observed in heavy cannabis-using youths. Results showed no significant difference between cannabis users and non-users on language, and small-to-moderate effects for simple motor skills.

CONCLUSION

Meta-analytical data on the acute effects of cannabis use on neurocognitive function have shown that cannabis intoxication leads to small to moderate deficits in several cognitive domains. These acute impairments accord with documented residual effects, suggesting that the detrimental effects of cannabis persist beyond acute intake.