Testing for cannabis in the work-place: a review of the evidence

Effects of recent cannabis consumption on eye-tracking and pupillometry

Introduction

Cannabis consumption is known to immediately affect ocular and oculomotor function, however, cannabis consumption is also known to affect it for a prolonged period of time. The purpose of this study is to identify an eye tracking or pupillometry metric which is affected after recent cannabis consumption but is not confounded by cannabis consumption history or demographic variables.

Methods

Quasi-experimental design. Participants who would consume inhalable cannabis (n = 159, mean age 31.0 years, 54% male) performed baseline neurobehavioral testing and eye-function assessments when they were sober. Eye function assessments included eye-tracking [gaze (point of visual focus), saccades (smooth movement)] and pupillometry. Participants then inhaled cannabis until they self-reported to be high and performed the same assessment again. Controls who were cannabis naïve or infrequent users (n = 30, mean age 32.6 years, 57% male) performed the same assessments without consuming cannabis in between.

Results

Cannabis significantly affected several metrics of pupil dynamics and gaze. Pupil size variability was the most discriminant variable after cannabis consumption. This variable did not change in controls on repeat assessment (i.e., no learning effect), did not correlate with age, gender, race/ethnicity, or self-reported level of euphoria, but did correlate with THC concentration of cannabis inhaled.

Discussion

A novel eye-tracking metric was identified that is affected by recent cannabis consumption and is not different from non-users at baseline. A future study that assesses pupil size variability at multiple intervals over several hours and quantifies cannabis metabolites in biofluids should be performed to identify when this variable normalizes after consumption and if it correlates with blood THC levels.

Urinary Excretion Profile of Cannabinoid Analytes Following Acute Administration of Oral and Vaporized Cannabis in Infrequent Cannabis Users

Traditionally, smoking has been the predominant method for administering cannabis, but alternative routes of administration have become more prevalent. Additionally, research examining urinary cannabinoid excretion profiles has primarily focused on 11-nor-9-carboxy-∆9-tetrahydrocannabinol (∆9-THC-COOH), a metabolite of ∆9-tetrahydrocannabinol (∆9-THC), as the primary analyte. The aim of the current study was to characterize the urinary excretion profile of ∆9-THC-COOH, ∆9-THC, ∆8-tetrahydrocannabinol (∆8-THC), 11-hydroxy-∆9-tetrahydrocannabinol (11-OH-∆9-THC), ∆9-tetrahydrocannabivarin (THCV), 11-nor-∆9-tetrahydrocannabivarin-9-carboxlic acid (THCV-COOH), cannabidiol (CBD), cannabinol (CBN) and 8,11-dihydroxytetrahydrocannabinol (8,11-diOH-∆9-THC) following controlled administration of both oral and vaporized cannabis. Participants (n = 21, 11 men/10 women) who were infrequent cannabis users ingested cannabis-containing brownies (0, 10 and 25 mg ∆9-THC) and inhaled vaporized cannabis (0, 5 and 20 mg ∆9-THC) across six double-blind outpatient sessions. Urinary concentrations of ∆9-THC analytes were measured at baseline and for 8 h after cannabis administration. Sensitivity, specificity and agreement between the three immunoassays (IAs) for ∆9-THC-COOH (cutoffs of 20, 50 and 100 ng/mL) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) analyses (confirmatory cutoff concentrations of 15 ng/mL) were assessed. Urinary concentrations for ∆9-THC-COOH, ∆9-THC, 11-OH-∆9-THC, THCV, CBN and 8,11-diOH-∆9-THC all peaked at 5-6 h and 4 h following oral and vaporized cannabis administration, respectively. At each active dose, median maximum concentrations (Cmax) for detected analytes were quantitatively higher after oral cannabis administration compared to vaporized. Using current recommended federal workplace drug-testing criteria (screening via IA with a cutoff of ≥50 ng/mL and confirmation via LC-MS-MS at a cutoff of ≥15 ng/mL), urine specimens tested positive for ∆9-THC-COOH in 97.6% of oral sessions and 59.5% of vaporized sessions with active ∆9-THC doses. These data indicate that while ∆9-THC-COOH may serve as the most consistent confirmatory analyte under the current drug-testing guidelines, future work examining 11-OH-∆9-THC under similar parameters could yield an alternative analyte that may be helpful in distinguishing between licit and illicit cannabis products.

Predictors of no, low and frequent emergency department use for any medical reason among patients with cannabis-related disorders attending Quebec (Canada) addiction treatment centres

INTRODUCTION

Patients with substance-related disorders and mental disorders (MD) contribute substantially to emergency department (ED) overcrowding. Few studies have identified predictors of ED use integrating service use correlates, particularly among patients with cannabis-related disorders (CRD). This study compared predictors of low (1-2 visits/year) or frequent (3+ visits/year) ED use with no ED use for a cohort of 9836 patients with CRD registered at Quebec (Canada) addiction treatment centres in 2012-2013.

METHODS

This longitudinal study used multinomial logistic regression to evaluate clinical, sociodemographic and service use variables from various databases as predictors of the frequency of ED use for any medical reason in 2015-2016 among patients with CRD.

RESULTS

Compared to non-ED users with CRD, frequent ED users included more women, rural residents, patients with serious MD and chronic CRD, dropouts from programs in addiction treatment centres and with less continuity of physician care. Compared with non-users, low ED users had more common MD and there more workers than students.

DISCUSSION AND CONCLUSIONS

Multimorbidity, including MD, chronic physical illnesses and other substance-related disorders than CRD, predicted more ED use and explained frequent use of outpatient services and prior specialised acute care, as did being 12-29 years, after controlling for all other covariates. Better continuity of physician care and reinforcement of programs like assertive community or integrated treatment, and chronic primary care models may protect against frequent ED use. Strategies like screening, brief intervention and treatment referral, including motivational therapy for preventing treatment dropout may also be expanded to decrease ED use.

Preparing for COVID-2x: Urban Planning Needs to Regard Urological Wastewater as an Invaluable Communal Public Health Asset and Not as a Burden

Prior to the COVID-19 pandemic, the analysis of urological wastewater had been a matter of academic curiosity and community-wide big-picture studies looking at drug use or the presence of select viruses such as Hepatitis. The COVID-19 pandemic saw systematic testing of urological wastewater emerge as a significant early detection tool for the presence of SARS-CoV-2 in a community. Even though the pandemic still rages in all continents, it is time to consider the post-pandemic world. This paper posits that urban planners should treat urological wastewater as a communal public health asset and that future sewer design should allow for stratified multi-order sampling.

Urinary Pharmacokinetic Profile of Cannabidiol (CBD), Δ9-Tetrahydrocannabinol (THC), and their Metabolites Following Oral and Vaporized CBD and Vaporized CBD-Dominant Cannabis Administration

The market for products containing cannabidiol (CBD) is booming globally. However, the pharmacokinetics of CBD in different oral formulations and the impact of CBD use on urine drug testing outcomes for cannabis (e.g., 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (∆9-THCCOOH)) are understudied. This study characterized the urinary pharmacokinetics of CBD (100 mg) following vaporization or oral administration (including 3 formulations: gelcap, pharmacy-grade syrup, or Epidiolex) as well as vaporized CBD-dominant cannabis (containing 100 mg CBD and 3.7 mg Δ9-THC) in healthy adults (n=18). A subset of participants (n=6) orally administered CBD syrup following overnight fasting (versus low-fat breakfast). Urine specimens were collected before and for 58 hours after dosing on a residential research unit. Immunoassay (IA) screening (cutoffs: 20, 50, 100 ng/mL) for ∆9-THCCOOH was performed, and quantitation of cannabinoids was completed via LC-MS-MS. Urinary CBD concentrations (ng/mL) were higher after oral (mean Cmax: 734; mean Tmax: 4.7 h, n=18) versus vaporized CBD (mean Cmax: 240; mean Tmax: 1.3 h, n=18), and oral dose formulation significantly impacted mean Cmax (Epidiolex=1274 ng/mL, capsule=776 ng/mL, syrup=151 ng/mL, n=6/group) with little difference in Tmax. Overnight fasting had limited impact on CBD excretion in urine, and there was no evidence of CBD conversion to ∆8- or ∆9-THC in any route or formulation in which pure CBD was administered. Following acute administration of vaporized CBD-dominant cannabis, 3 of 18 participants provided a total of 6 urine samples in which ∆9-THCCOOH concentrations ≥15 ng/mL. All 6 specimens screened positive at a 20 ng/mL IA cutoff, and 2 of 6 screened positive at a 50 ng/mL cutoff. These data show that absorption/elimination of CBD is impacted by drug formulation, route of administration, and gastric contents. Although pure CBD is unlikely to impact drug testing, it is possible that hemp products containing low amounts of ∆9-THC may produce a cannabis-positive urine drug test.

The why behind the high: determinants of neurocognition during acute cannabis exposure

Acute cannabis intoxication may induce neurocognitive impairment and is a possible cause of human error, injury and psychological distress. One of the major concerns raised about increasing cannabis legalization and the therapeutic use of cannabis is that it will increase cannabis-related harm. However, the impairing effect of cannabis during intoxication varies among individuals and may not occur in all users. There is evidence that the neurocognitive response to acute cannabis exposure is driven by changes in the activity of the mesocorticolimbic and salience networks, can be exacerbated or mitigated by biological and pharmacological factors, varies with product formulations and frequency of use and can differ between recreational and therapeutic use. It is argued that these determinants of the cannabis-induced neurocognitive state should be taken into account when defining and evaluating levels of cannabis impairment in the legal arena, when prescribing cannabis in therapeutic settings and when informing society about the safe and responsible use of cannabis.

Cannabis and Cognitive Functioning: From Acute to Residual Effects, From Randomized Controlled Trials to Prospective Designs

In recent years, several jurisdictions have revised their regulation policy toward both medical and recreational use of cannabis. These changes have elicited concerns regarding how legalization impacts academic achievement and work performance. This review evaluates the acute and long-term (residual) association between cannabis use and cognitive functioning that underlies poor academic and work performance. Relative to other reviews, this article focuses on cross-over randomized controlled trials and prospective designs given that they allow to test the impairing effects of cannabis exposure at the within-subject level. Acute cannabis cognitive effects are discussed separately for known confounding factors such as levels of delta-9-tetrahydrocannabinol (Δ⁹-THC), Δ⁹-THC:cannabidiol ratio, previous cannabis use and, comorbidity with psychosis-spectrum disorders. The cognitive residual effects of cannabis are detailed in relation to duration of abstinence, frequency of use, comorbidity with psychosis-spectrum disorders, types of cognitive domains assessed, and age of cannabis use initiation. Moreover, considering the fact that adequate longitudinal studies can make inferences about causality between cannabis use and impaired cognitive functioning when disentangling between-subject from within-subject variation, proofs for the three main non-mutually exclusive hypotheses about this relationship will be presented: i) the cognitive vulnerability hypothesis as part of the more general common antecedent hypothesis, ii) the concurrent cannabis impairing hypothesis, and iii) the neurotoxic hypothesis of cannabis. Current research provides evidence for mild to moderate acute cannabis effects on episodic and working memory, processing speed, and executive functions. Mild residual impairing effects were also observed in these exact same cognitive domains, suggesting that adverse effects following cannabis intoxication persist at least days or weeks following cannabis abstinence. Relative to adult-onset, adolescent-onset cannabis use seems to explain the dose-response relationship and is associated with longer lasting residual effects even in mild users (<weekly). The association between cannabis and cognition is likely explained by common antecedents, such that genetic and shared environment factors predispose individuals to both cannabis use and cognitive deficits, and to a lesser degree, neurotoxic effects.

Cannabis and work: Need for more research

Cannabis sativa is one of the oldest and most widely used plants in the world with a variety of industrial, medical, and nonmedical applications. Despite its long history, cannabis-derived products remain a source of controversy across the fields of medicine, law, and occupational safety and health. More favorable public attitudes about cannabis in the US have resulted in greater access to cannabis through legalization by states, leading to more consumption by workers. As more states adopt cannabis access laws, and as more workers choose to consume cannabis products, the implications for existing workplace policies, programs, and practices become more salient. Past workplace practices were grounded in a time when cannabis consumption was always viewed as problematic, considered a moral failing, and was universally illegal. Shifting cultural views and the changing legal status of cannabis indicate a need for research into the implications and challenges relating to cannabis and work. This commentary suggests research needs in the following areas: (a) data about industries and occupations where cannabis consumption among workers is most prevalent; (b) adverse health consequences of cannabis consumption among workers; (c) workplace supported recovery programs; (d) hazards to workers in the emerging cannabis industry; (e) relationship between cannabis consumption and occupational injuries; (f) ways to assess performance deficits and impairment from cannabis consumption; (g) consumption of synthetic cannabinoids to evade detection by drug testing; (h) cannabis consumption and its effect on occupational driving; and (i) ways to craft workplace policies and practices that take into consideration conflicting state and federal laws pertaining to cannabis.

Blunted highs: Pharmacodynamic and behavioral models of cannabis tolerance

Acute exposure to cannabis comes with neurocognitive impairment, leading to increased risk of human error and injury. Evidence however indicates that such acute effects are less prominent in chronic users, suggesting cannabis tolerance. Models of cannabis tolerance stress the importance of neurobiological or behavioral adaptations following repeated cannabis exposure. The pharmacodynamic model relates neuroadaptive changes in the brain to a blunted response to cannabis. Downregulation of CB1 receptors in chronic cannabis users has been associated with a normalization of dopaminergic output from the ventral tegmental area to the mesolimbic circuit, and a reduction of impairment during acute cannabis exposure. Such neuroadaptions are absent in occasional users, who show strong increments of dopamine and glutamate levels in the striatum, a loss of functional connectivity within the mesolimbic circuit and neurocognitive impairments when exposed to cannabis. Evidence for a behavioral model of cannabis tolerance that poses that users can have volitional control to overcome functional impairment during cannabis intoxication is relatively weak, and at best shows limited control over a limited number of behavioral functions. Cannabis tolerance is most likely to occur in users that consume high doses of cannabis continuously, at a high pace, for a prolonged period of time. Knowledge on frequency, dose and duration of cannabis use that is needed to achieve, maintain or lessen tolerance however is very limited, but will be of importance in the context of cannabis therapeutics and in legal settings when evaluating the impact of cannabis exposure on human function.

Thermographic detection and quantification of THC in oral fluid at unprecedented low concentrations

With recent changes in the legalization of cannabis around the world, there is an urgent need for rapid, yet sensitive, screening devices for testing drivers and employees under the influence of cannabis at the roadside and at the workplace, respectively. Oral fluid lateral flow immunoassays (LFAs) have recently been explored for such applications. While LFAs offer on-site, low-cost and rapid detection of tetrahydrocannabinol (THC), their nominal detection threshold is about 25 ng/ml, which is well above the 1-5 ng/ml per se limits set by regulations. In this paper, we report on the development of a thermo-photonic imaging system that utilizes the commercially available low-cost LFAs but offers detection of THC at unprecedented low concentrations. Our reader technology examines photothermal responses of gold nanoparticles (GNPs) in LFA through lock-in thermography (LIT). Our results (n = 300) suggest that the demodulation of localized surface plasmon resonance responses of GNPs captured by infrared cameras allows for detection of THC concentrations as low as 2 ng/ml with 96% accuracy. Quantification of THC concentration is also achievable with our technology through calibration.

Urinary Pharmacokinetic Profile of Cannabinoids Following Administration of Vaporized and Oral Cannabidiol and Vaporized CBD-Dominant Cannabis

Cannabis products in which cannabidiol (CBD) is the primary chemical constituent (CBD-dominant) are increasingly popular and widely available. The impact of CBD exposure on urine drug testing has not been well studied. This study characterized the urinary pharmacokinetic profile of 100-mg oral and vaporized CBD, vaporized CBD-dominant cannabis (100-mg CBD; 3.7-mg ∆9-THC) and placebo in healthy adults (n = 6) using a within-subjects crossover design. Urine specimens were collected before and for 5 days after drug administration. Immunoassay (IA) screening (cutoffs of 20, 50 and 100 ng/mL) and LC-MS-MS confirmatory tests (cutoff of 15 ng/mL) for 11-nor-9-carboxy-∆9-tetrahydrocannabinol (∆9-THCCOOH) were performed; urine was also analyzed for CBD and other cannabinoids. Urinary concentrations of CBD were higher after oral (mean Cmax: 776 ng/mL) versus vaporized CBD (mean Cmax: 261 ng/mL). CBD concentrations peaked 5 h after oral CBD ingestion and within 1 h after inhalation of vaporized CBD. After pure CBD administration, only 1 out of 218 urine specimens screened positive for ∆9-THCCOOH (20-ng/mL IA cutoff) and no specimens exceeded the 15-ng/mL confirmatory cutoff. After inhalation of CBD-dominant cannabis vapor, nine samples screened positive at the 20-ng/mL IA cutoff, and two of those samples screened positive at the 50-ng/mL IA cutoff. Four samples that screened positive (two at 20 ng/mL and two at 50 ng/mL) confirmed positive with concentrations of ∆9-THCCOOH exceeding 15 ng/mL. These data indicate that acute dosing of pure CBD will not result in a positive urine drug test using current federal workplace drug testing guidelines (50-ng/mL IA cutoff with 15-ng/mL confirmatory cutoff). However, CBD products that also contain ∆9-THC may produce positive urine results for ∆9-THCCOOH. Accurate labeling and regulation of ∆9-THC content in CBD/hemp products are needed to prevent unexpected positive drug tests and unintended drug effects.

Urinary Excretion Profile of 11-Nor-9-Carboxy-Δ9-Tetrahydrocannabinol (THCCOOH) Following Smoked and Vaporized Cannabis Administration in Infrequent Cannabis Users

As cannabis has become more accessible, use of alternative methods for cannabis administration such as vaporizers has become more prevalent. Most prior controlled pharmacokinetic evaluations have examined smoked cannabis in frequent (often daily) cannabis users. This study characterized the urinary excretion profile of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH), the primary analytical outcome for detection of cannabis use, among infrequent cannabis users following controlled administration of both smoked and vaporized cannabis. Healthy adults (N = 17), with a mean of 398 (range 30-1,825) days since last cannabis use, smoked and vaporized cannabis containing 0, 10, and 25 mg of Δ9-tetrahydrocannabinol (THC) across six outpatient sessions. Urinary concentrations of THCCOOH were measured at baseline and for 8 h after cannabis administration. Sensitivity, specificity, and agreement between three immunoassays (IA) for THCCOOH (with cutoffs of 20, 50, and 100 ng/mL) and gas chromatography-mass spectrometry (GC/MS) results (confirmatory concentration of 15 ng/mL) were assessed. THCCOOH concentrations peaked 4-6 h after cannabis administration. Median maximum concentrations (Cmax) for THCCOOH were qualitatively higher after administration of vaporized cannabis compared to equal doses of smoked cannabis. Urine THCCOOH concentrations were substantially lower in this study relative to prior examinations of experienced cannabis users. The highest agreement between IA and GC/MS was observed at the 50 ng/mL IA cutoff while sensitivity and specificity were highest at the 20 and 100 ng/mL IA cutoffs, respectively. Using federal workplace drug-testing criteria (IA cutoff of 50 ng/mL and GC/MS concentration ≥15 ng/mL) urine specimens tested positive in 47% of vaporized sessions and 21% of smoked sessions with active THC doses (N = 68). Urinary concentrations of THCCOOH are dissimilar after administration of smoked and vaporized cannabis, with qualitatively higher concentrations observed after vaporization. Infrequent users of cannabis may excrete relatively low concentrations of THCCOOH following acute inhalation of smoked or vaporized cannabis.

Systematic Review of Cannabis Use and Risk of Occupational Injury

Aim: A range of nations, including countries of the European Union, Australia, and the Americas have recently implemented or proposed reforms to how they control cannabis use, thereby departing from traditional approaches of criminal prohibition that have dominated throughout most of the twentieth century. Given these policy developments and the widespread global use of cannabis, it is critically important to understand the possible risks associated with cannabis use in relation to major societal harms. Methods: This systematic review investigates the potential link between cannabis use and occupational injury. Consequently, it appraises all available current literature from five databases, following Cochrane and PRISMA guidelines. Results: Seven of the 16 reviewed studies show evidence supporting a positive association between cannabis use and occupational injury. One study shows evidence supporting a negative association and the remaining eight studies show no evidence of a significant relation. None of the studies assessed cannabis-related impairment. Only three of the reviewed studies show clear evidence that cannabis use preceded the occupational-injury event. Conclusion: The current body of evidence does not provide sufficient evidence to support the position that cannabis users are at increased risk of occupational injury. Further, the study quality assessment suggests significant biases in the extant literature are present due to potential confounding variables, selection of participants, and measurement of exposures and outcomes. Future high-quality evidence will be needed to elucidate the relation between cannabis use and occupational injury.

Evaluation of a workshop to address drugs and alcohol in the workplace

Purpose

Risky alcohol and other drug (AOD) use is ubiquitous in some workplace cultures, and is associated with considerable risks to health, safety and productivity. A workplace drug and alcohol first aid program was developed to support supervisors and managers to recognize and respond appropriately to AOD problems, increase knowledge of AOD and reduce the stigma associated with AOD. The purpose of this paper is to undertake an evaluation to assess the program’s efficacy.

Design/methodology/approach

A self-report survey was administered to program participants before (T1), immediately after (T2) and three months following program completion (T3). Changes in alcohol/drug-related knowledge, role adequacy, motivation and personal views were examined using repeated measures ANOVA.

Findings

A total of 109 participants took part in the program, with only 26 completing scores at all three time points. Mean scores increased significantly (p<0.05) between T1 and T2 for knowledge (12.7–16.0), role adequacy (11.8–17.4), motivation (9.7–10.4) and personal views (9.0–9.6). Significant improvements were maintained at T3 for knowledge (15.1) and role adequacy (17.3).

Practical implications

Drug and alcohol first aid programs offer a potentially valuable initiative to improve the knowledge, skills and understanding of managers and supervisors in tackling workplace AOD risks, associated stigma and improving help seeking.

Originality/value

Workplace programs for managers can facilitate organization-wide responses to the reduction of AOD-related problems, increase implementation of appropriate policy and interventions, minimize associated harms and stigma and reduce negative imposts on productivity and profit.

Pharmacokinetic Characterization of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol in Urine Following Acute Oral Cannabis Ingestion in Healthy Adults

Understanding the urine excretion profile for Δ9-tetrahydrocannabinol (THC) metabolites is important for accurate detection and interpretation of toxicological testing for cannabis use. Prior literature has primarily evaluated the urinary pharmacokinetics of the non-psychoactive THC metabolite 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) following smoked cannabis administration. The present study examined the urine THCCOOH excretion profile following oral cannabis administration in 18 healthy adults. Following ingestion of a cannabis-containing brownie with 10, 25 or 50 mg of THC (N = 6 per dose), urine specimens were collected on a closed residential research unit for 6 days, followed by three outpatient visits on Days 7-9. Average maximum concentrations (Cmax) of THCCOOH were 107, 335 and 713 ng/mL, and average times to maximum concentration (Tmax) were 8, 6 and 9 h for the 10, 25 and 50 mg THC doses, respectively. Detection windows to first positive and last positive varied as a function of dose; higher doses had shorter time to first positive and longer time to last positive. Considerable inter-subject variability was observed on study outcomes. Gas chromatography/mass spectrometry (GC/MS; 15 ng/mL cutoff) was used as the criterion to assess sensitivity, specificity and agreement for THCCOOH qualitative immunoassay tests using 20, 50 and 100 ng/mL cutoffs. The 50 ng/mL cutoff displayed good sensitivity (92.5%), specificity (92.4%) and overall agreement (92.4%), whereas the 20 ng/mL cutoff demonstrated poor specificity (58.4%), and the 100 ng/mL cutoff exhibited reduced sensitivity (70.9%). Ingestion of cannabis brownies containing the 10 and 25 mg THC doses yielded THCCOOH concentrations that differed in magnitude and time course from those previously reported for the smoked route of administration of comparable doses.

Marijuana use among adults: Initiation, return to use, and continued use versus quitting over a one-year follow-up period

BACKGROUND

This study examined factors associated with marijuana use initiation among never users, prior-to-past year user who return to use, and users who continue use over a 12-month follow-up period.

METHODS

Two waves (W1 and W2) of the Population Assessment of Tobacco and Health (PATH) Study provided data (N=26,204 aged 18+). Multivariable logistic regression models were used to examine associations of W1 sociodemographic, health/mental health, and other substance use characteristics with W2 use status. As applicable, marijuana initiation age, use frequency, and use problems were also examined.

RESULTS

At W2, 2.36% and 10.42% of W1 never users and prior-to-past year users, respectively, reported having used marijuana, and 72.54% of W1 past-year users reported continued use. Those in the 18-24 age group were most likely to initiate, resume, or continue use. Among never and prior-to-past year users, those who reported more mental health problems at W1 also had greater odds of use at W2. Marijuana initiation and return to use were significantly associated with movement from nonuse to use of other substances. Continued marijuana use, as opposed to quitting, was also associated with other substance use, initiation of marijuana use prior to age 18, weekly or more frequent use (AOR=2.34, 95% CI=1.87-2.93), and use problems (AOR=1.40, 95% CI=1.05-1.85) reported at W1.

CONCLUSIONS

Movement between marijuana nonuse and use was substantial during the 12-month follow-up period. Early intervention to prevent initiation of, return to, and continued marijuana and other substance use, especially among young adults, is needed.

Seven years of workplace drug testing in Italy: A systematic review and meta-analysis

In Italy, Workplace Drug Testing (WDT) has been compulsory by law for specific categories of workers since 2008, offering the opportunity to compare studies conducted within a single regulatory framework. The aims of this paper are to estimate the overall prevalence of WDT positivity (at screening survey) among Italian workers and evaluate the percentage of true and false positives at confirmation analysis. A systematic review and meta-analysis of the scientific literature on WDT in Italy from January 2008 to March 2015 was carried out, according to the MOOSE guidelines. A random effects model was utilized to calculate pooled prevalence. Potential sources of heterogeneity were explored using sensitivity test and subgroup analysis. The overall meta-analytical prevalence of positivity at WDT among Italian workers was 1.4% [95% confidence interval (CI) = 1.1-1.7%]. It was significantly lower among workers screened with an on-site test (1%; 95% CI = 0.5-1.5%), compared with a bench-top test (1.7%; 95% CI = 1.3-2.1%). Nine studies provided data on false positives at the screening test, with a combined prevalence estimate - calculated on positive cases - of 30% (95% CI = 16-44%). In Italy, the number of true positives at first-level workplace drug testing is low, while the frequency of false positives is relatively high. A revision of the Italian legislation on the subject seems advisable. Copyright © 2017 John Wiley & Sons, Ltd.

Rapid quantification of free and glucuronidated THCCOOH in urine using coated well plates and LC–MS/MS analysis

Aim: Generally, urine drug testing for cannabis abuse involves measuring total concentrations of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) obtained by enzymatic and/or alkaline hydrolysis of THCCOOH-glucuronide. As hydrolysis can be inconsistent and incomplete, direct measurement of the two metabolites is preferable. Methodology & results: We developed a high-throughput LC–MS/MS method for simultaneous quantification of free and glucuronidated THCCOOH in urine using coated 96-well plates for analyte extraction and column-switching chromatography. Excellent separation of the two analytes was achieved within 2.5 min, with linear ranges from 5 to 2000 μg/l for THCCOOH and from 10 to 4000 μg/l for THCCOOH-glucuronide. Conclusion: The method was successfully validated and applied to authentic urine samples from cannabis consumers, demonstrating its applicability for routine cannabinoid testing.

Simultaneous quantification of 11 cannabinoids and metabolites in human urine by liquid chromatography tandem mass spectrometry using WAX-S tips

A comprehensive cannabinoid urine quantification method may improve clinical and forensic result interpretation and is necessary to support our clinical research. A liquid chromatography tandem mass spectrometry quantification method for ∆(9)-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), 11-nor-9-carboxy-THC (THCCOOH), ∆(9)-tetrahydrocannabinolic acid (THCAA), cannabinol (CBN), cannabidiol (CBD), cannabigerol (CBG), ∆(9)-tetrahydrocannabivarin (THCV), 11-nor-9-carboxy-THCV (THCVCOOH), THC-glucuronide (THC-gluc), and THCCOOH-glucuronide (THCCOOH-gluc) in urine was developed and validated according to the Scientific Working Group on Toxicology guidelines. Sample preparation consisted of disposable pipette extraction (WAX-S) of 200 μL urine. Separation was achieved on a Kinetex C18 column using gradient elution with flow rate 0.5 mL/min, mobile phase A (10 mM ammonium acetate in water), and mobile phase B (15 % methanol in acetonitrile). Total run time was 14 min. Analytes were monitored in both positive and negative ionization modes by scheduled multiple reaction monitoring. Linear ranges were 0.5-100 μg/L for THC and THCCOOH; 0.5-50 μg/L for 11-OH-THC, CBD, CBN, THCAA, and THC-gluc; 1-100 μg/L for CBG, THCV, and THCVCOOH; and 5-500 μg/L for THCCOOH-gluc (R (2) > 0.99). Analytical biases were 88.3-113.7 %, imprecisions 3.3-14.3 %, extraction efficiencies 42.4-81.5 %, and matrix effect -10 to 32.5 %. We developed and validated a comprehensive, simple, and rapid LC-MS/MS cannabinoid urine method for quantification of 11 cannabinoids and metabolites. This method is being used in a controlled cannabis administration study, investigating urine cannabinoid markers documenting recent cannabis use, chronic frequent smoking, or route of drug administration and potentially improving urine cannabinoid result interpretation.

Perceived Risk of Low-Back Injury Among Four Occupations

OBJECTIVE

This study aimed to assess the perception of risk of low-back injury of individuals from four groups: office/administrative employees, dental workers (dentists/dental hygienists), firefighters, and undergraduate students.

BACKGROUND

The concept of worker's perception of injury risk has been used to set safe material-handling limits and to determine compliance with health and safety regulations but has not been used to identify perceptual differences among occupations or potential deficiencies in risk awareness.

METHOD

Participants (N = 232) were presented with eight images of different low-back postures/tasks and were required to rate their perceived magnitude of low-back risk on a scale from 0 (no risk) to 10 (extreme risk).

RESULTS

Office/administrative and dental workers rated postures higher than firefighters and students. Individuals from all groups perceived kyphotic postures as having a higher low-back risk than lordotic postures. Further, office and dental workers, compared to firefighters and students, perceived sitting postures to have a relatively higher level of risk, likely due to these postures being typically adopted by these individuals at work. No relationship between previous low-back pain and risk rating was observed in this study.

CONCLUSION

Low-back injury risk perception varies between occupations/groups and may be a result of different exposures.

APPLICATION

The results of this study can potentially be used to implement occupation-specific training programs to ensure that the scientific research regarding low-back injuries is being properly conveyed to employees across all sectors.

Workers' Risk Tolerance and Occupational Injuries

This study explores the relationship between individuals' risk tolerance and occupational injuries. We analyze data from a national representative survey of U.S. workers that includes information about injuries, risk tolerance, cognitive and noncognitive attributes, and risky behaviors. We measure risk tolerance through questions regarding individuals' willingness to gamble on their lifetime income. We estimate zero-inflated count models to assess the role played by such measures on workers' recurrent injuries. We discuss some implications of our results for future research and occupational safety policies. Our results highlight the concurrent and changing role played by individual, work, and environmental factors in explaining recurrent incidents. They show that risk tolerance affects recurrent injuries, although not in the direction that proponents of the concept of proneness would expect. Our measure of risk aversion shows that individuals who are somewhat more risk tolerant have fewer recurrent injuries than those who are risk averse. But the estimated relationship is U-shaped, not monotonic and, therefore, not easy to predict. At the same time, we find that individuals' "revealed risk preferences"-specific risky behaviors-are related to higher injury probabilities. Demanding working conditions, measures of socioeconomic status, health, and safety problems experienced by workers during their youth remain among the most important factors explaining the phenomena of recurrent injuries. So our results contribute also to the important debate about the relationship between health and socioeconomic status.

Clinical perspectives on medical marijuana (cannabis) for neurologic disorders

The American Academy of Neurology published an evidence-based systematic review of randomized controlled trials using marijuana (Cannabis sativa) or cannabinoids in neurologic disorders. Several cannabinoids showed effectiveness or probable effectiveness for spasticity, central pain, and painful spasms in multiple sclerosis. The review justifies insurance coverage for dronabinol and nabilone for these indications. Many insurance companies already cover these medications for other indications. It is unlikely that the review will alter coverage for herbal marijuana. Currently, no payers cover the costs of herbal medical marijuana because it is illegal under federal law and in most states. Cannabinoid preparations currently available by prescription may have a role in other neurologic conditions, but quality scientific evidence is lacking at this time.

How effective is drug testing as a workplace safety strategy? A systematic review of the evidence

The growing prevalence of workplace drug testing and the narrow scope of previous reviews of the evidence base necessitate a comprehensive review of research concerning the efficacy of drug testing as a workplace strategy. A systematic qualitative review of relevant research published between January 1990 and January 2013 was undertaken. Inclusion criteria were studies that evaluated the effectiveness of drug testing in deterring employee drug use or reducing workplace accident or injury rates. Methodological adequacy was assessed using a published assessment tool specifically designed to assess the quality of intervention studies. A total of 23 studies were reviewed and assessed, six of which reported on the effectiveness of testing in reducing employee drug use and 17 which reported on occupational accident or injury rates. No studies involved randomised control trials. Only one study was assessed as demonstrating strong methodological rigour. That study found random alcohol testing reduced fatal accidents in the transport industry. The majority of studies reviewed contained methodological weaknesses including; inappropriate study design, limited sample representativeness, the use of ecological data to evaluate individual behaviour change and failure to adequately control for potentially confounding variables. This latter finding is consistent with previous reviews and indicates the evidence base for the effectiveness of testing in improving workplace safety is at best tenuous. Better dissemination of the current evidence in relation to workplace drug testing is required to support evidence-informed policy and practice. There is also a pressing need for more methodologically rigorous research to evaluate the efficacy and utility of drug testing.

Current knowledge on cannabinoids in oral fluid

Oral fluid (OF) is a new biological matrix for clinical and forensic drug testing, offering non-invasive and directly observable sample collection reducing adulteration potential, ease of multiple sample collections, lower biohazard risk during collection, recent exposure identification, and stronger correlation with blood than urine concentrations. Because cannabinoids are usually the most prevalent analytes in illicit drug testing, application of OF drug testing requires sufficient scientific data to support sensitive and specific OF cannabinoid detection. This review presents current knowledge of OF cannabinoids, evaluating pharmacokinetic properties, detection windows, and correlation with other biological matrices and impairment from field applications and controlled drug administration studies. In addition, onsite screening technologies, confirmatory analytical methods, drug stability, and effects of sample collection procedure, adulterants, and passive environmental exposure are reviewed. Delta-9-tetrahydrocannabinol OF concentrations could be >1000 µg/L shortly after smoking, whereas minor cannabinoids are detected at 10-fold and metabolites at 1000-fold lower concentrations. OF research over the past decade demonstrated that appropriate interpretation of test results requires a comprehensive understanding of distinct elimination profiles and detection windows for different cannabinoids, which are influenced by administration route, dose, and drug use history. Thus, each drug testing program should establish cut-off criteria, collection/analysis procedures, and storage conditions tailored to its purposes. Building a scientific basis for OF testing is ongoing, with continuing OF cannabinoids research on passive environmental exposure, drug use history, donor physiological conditions, and oral cavity metabolism needed to better understand mechanisms of cannabinoid OF disposition and expand OF drug testing applicability. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Cannabis cue-induced brain activation correlates with drug craving in limbic and visual salience regions: preliminary results

Craving is a major motivator underlying drug use and relapse but the neural correlates of cannabis craving are not well understood. This study sought to determine whether visual cannabis cues increase cannabis craving and whether cue-induced craving is associated with regional brain activation in cannabis-dependent individuals. Cannabis craving was assessed in 16 cannabis-dependent adult volunteers while they viewed cannabis cues during a functional MRI (fMRI) scan. The Marijuana Craving Questionnaire was administered immediately before and after each of three cannabis cue-exposure fMRI runs. FMRI blood-oxygenation-level-dependent (BOLD) signal intensity was determined in regions activated by cannabis cues to examine the relationship of regional brain activation to cannabis craving. Craving scores increased significantly following exposure to visual cannabis cues. Visual cues activated multiple brain regions, including inferior orbital frontal cortex, posterior cingulate gyrus, parahippocampal gyrus, hippocampus, amygdala, superior temporal pole, and occipital cortex. Craving scores at baseline and at the end of all three runs were significantly correlated with brain activation during the first fMRI run only, in the limbic system (including amygdala and hippocampus) and paralimbic system (superior temporal pole), and visual regions (occipital cortex). Cannabis cues increased craving in cannabis-dependent individuals and this increase was associated with activation in the limbic, paralimbic, and visual systems during the first fMRI run, but not subsequent fMRI runs. These results suggest that these regions may mediate visually cued aspects of drug craving. This study provides preliminary evidence for the neural basis of cue-induced cannabis craving and suggests possible neural targets for interventions targeted at treating cannabis dependence.

Oral fluid/plasma cannabinoid ratios following controlled oral THC and smoked cannabis administration

Oral fluid (OF) is a valuable biological alternative for clinical and forensic drug testing. Evaluating OF to plasma (OF/P) cannabinoid ratios provides important pharmacokinetic data on the disposition of drug and factors influencing partition between matrices. Eleven chronic cannabis smokers resided on a closed research unit for 51 days. There were four 5-day sessions of 0, 30, 60, and 120 mg oral ∆(9)-tetrahydrocannabinol (THC)/day followed by a five-puff smoked cannabis challenge on Day 5. Each session was separated by 9 days ad libitum cannabis smoking. OF and plasma specimens were analyzed for THC and metabolites. During ad libitum smoking, OF/P THC ratios were high (median, 6.1; range, 0.2-348.5) within 1 h after last smoking, decreasing to 0.1-20.7 (median, 2.1) by 13.0-17.1 h. OF/P THC ratios also decreased during 5-days oral THC dosing, and after the smoked cannabis challenge, median OF/P THC ratios decreased from 1.4 to 5.5 (0.04-245.6) at 0.25 h to 0.12 to 0.17 (0.04-5.1) at 10.5 h post-smoking. In other studies, longer exposure to more potent cannabis smoke and oromucosal cannabis spray was associated with increased OF/P THC peak ratios. Median OF/P 11-nor-9-carboxy-THC (THCCOOH) ratios were 0.3-2.5 (range, 0.1-14.7) ng/μg, much more consistent in various dosing conditions over time. OF/P THC, but not THCCOOH, ratios were significantly influenced by oral cavity contamination after smoking or oromucosal spray of cannabinoid products, followed by time-dependent decreases. Establishing relationships between OF and plasma cannabinoid concentrations is essential for making inferences of impairment or other clinical outcomes from OF concentrations.

An analysis of ethical issues in using wastewater analysis to monitor illicit drug use

AIMS

To discuss ethical issues that may arise in using WWA to monitor illicit drug use in the general population and in entertainment precincts, prisons, schools and work-places.

METHOD

Review current applications of WWA and identify ethical and social issues that may be raised with current and projected future uses of this method.

RESULTS

Wastewater analysis (WWA) of drug residues is a promising method of monitoring illicit drug use that may overcome some limitations of other monitoring methods. When used for monitoring purposes in large populations, WWA does not raise major ethical concerns because individuals are not identified and the prospects of harming residents of catchment areas are remote. When WWA is used in smaller catchment areas (entertainment venues, prisons, schools or work-places) their results could, possibly, indirectly affect the occupants adversely. Researchers will need to take care in reporting their results to reduce media misreporting. Fears about possible use of WWA for mass individual surveillance by drug law enforcement officials are unlikely to be realized, but will need to be addressed because they may affect public support adversely for this type of research.

CONCLUSIONS

Using wastewater analysis to monitor illicit drug use in large populations does not raise major ethical concerns, but researchers need to minimize possible adverse consequences in studying smaller populations, such as workers, prisoners and students.

The accuracy of self-reported data concerning recent cannabis use in the French armed forces

BACKGROUND

The aims were to evaluate the accuracy of self-report of past-month cannabis use in a representative sample of French military staff members and to evaluate the scale of the prevarication bias.

METHOD

Data from three cross-sectional surveys conducted between 2005 and 2008 (n = 3493) were used. The characteristics of self-report (sensitivity, specificity, positive predictive value and negative predictive value) were computed using tetrahydrocannabinol detection in urine as the reference.

RESULTS

The prevalence for past-month cannabis use was 16.1% and for positive testing was 13.4%. The discriminant power of self-report was good, with an area under the receiver operating characteristics curve 0.90. Specificity (94.5%) and negative predictive values (97.8%) were good, but sensitivity (85.7%) and positive predictive values (70.4%) were lower. The lowest sensitivity values were observed in the higher categories of personnel and in the Navy, which could reflect some prevarication in these sub-populations who might believe they were more exposed to sanctions if detected.

CONCLUSIONS

Despite certain limitations of urine analysis as a reference, because of its poor detection of occasional users, our study is in favour of good accuracy of self-reported data on cannabis use, even among the military. However, our results, derived from a population study, do not enable any assumptions on the validity of self-reported data collected during individual testing procedures for the purpose of improving occupational safety.

The negative impact of attention-deficit/hyperactivity disorder on occupational health in adults and adolescents

PURPOSE

To review the negative effects of attention-deficit/hyperactivity disorder (ADHD) in adolescence and adulthood on work productivity and occupational health.

METHODS

A review of the MEDLINE database was carried out to identify direct and indirect effects of ADHD on work, employment and occupational health.

RESULTS

ADHD is associated with higher levels of unemployment versus controls. Adults with ADHD who are employed experience workplace impairment and reduced productivity, as well as behavioural issues such as irritability and low frustration tolerance. Adults with ADHD are also at increased risk of accidents, trauma and workplace injuries, particularly traffic accidents. Indirect effects of ADHD on occupational health include reduced educational achievement and increased rates of substance abuse and criminality. Overall, ADHD in adults has a substantial economic impact as a result of absenteeism and lost productivity. Psychoeducation, combined with stimulant medications if necessary, is recommended as first-line treatment for adults with ADHD. Limited data available suggest that stimulant treatment can improve work productivity and efficacy, and reduce the risks associated with driving, although further studies are necessary.

CONCLUSIONS

ADHD can affect the ability to gain and maintain employment and to work safely and productively. As ADHD is a treatable condition, patients, employers and physicians have a role to play in ensuring optimal occupational health.