Recent Cannabis Use Research Articles

Association between recent cannabinoid use and acute ischemic stroke.

Studies that have analyzed the association between cannabis use and acute ischemic stroke (AIS) have provided conflicting results. In this study, we aim to determine the association of recent cannabis use detected through urine drug screen (UDS) among patients admitted with AIS. A retrospective observational study was performed using the medical records database. All patients aged 18 years and older admitted from January 1, 2015, to December 31, 2017, who underwent urine toxicology testing on admission were included in the analysis. Multivariate logistic regression analysis was performed to analyze independent association between recent cannabis use and AIS. A total of 9,350 patients were determined to have undergone UDS during admission, and 18% (1,643) of this had a positive urine cannabis test. Unadjusted risk ratio showed a 50% decrease in risk of AIS among cannabis users (risk ratio = 0.505, 95% confidence interval [CI] 0.425-0.600). The effect was lost after adjusting for age, race, ethnicity, sickle cell disease, dyslipidemia, hypertension, obesity, diabetes mellitus, cigarette smoking, atrial fibrillation, and other cardiac conditions (odds ratio 1.038, 95% CI 0.773-1.394). This is one of the few studies analyzing the association of recent cannabis use and AIS using admission urine toxicology test independent of polysubstance use. Although our study has limitations, we did not find an independent association between recent cannabis use and the incidence of AIS. Further studies using urine toxicology tests with larger sample size and including dosage of cannabis exposure should be conducted.

1023 Oncologists’ Beliefs About Medical Marijuana’s Effectiveness for Sleep in Cancer Patients: A Nationally Representative Survey

Abstract Introduction Cancer is a qualifying condition for medical marijuana (MM) access in almost every state which has legalized medical use. Over 20% of patients report recent cannabis use to manage cancer treatment side effects, including poor sleep. However, there have been no clinical trials of MM for sleep in oncology populations. This study explores oncologists’ characteristics associated with their views on MM for sleep. Methods N=237 medical oncologists completed a mailed survey querying demographics, training history and current practice, and their knowledge and views on MM. In these analyses, we compared oncologists who viewed MM as being equally or more effective than standard treatment approaches to manage poor sleep with those who viewed MM as less effective. Results Sixty-four percent of oncologists believed MM to be equally or more effective than standard treatments for poor sleep. They were significantly less likely than peers to have a medical school faculty appointment (53% vs 72%) or self-report sufficient knowledge about MM to make clinical recommendations (42% vs 57%). Oncologists who viewed MM favorably compared to standard treatments for poor sleep were more likely to have recommended its use and to view it as beneficial during end of life care. We identified no differences between groups by age, sex, ethnicity, US vs foreign medical training, patient volume, or whether the state where they practiced had legalized MM. Conclusion Oncologists affiliated with a medical school report less knowledge about MM and are more cautious in their views of its effectiveness for treating poor sleep. This may be due to their institutions’ reluctance to draft MM policies for fear of losing federal licensure or their awareness of the limitations of existing data. There are important practice implications related to the likelihood of an oncologist recommending MM for poor sleep. Support Hans and Mavis Lopater Foundation.

Recent Use of Synthetic Cannabinoids, Synthetic Opioids, and Other Psychoactive Drug Groups among High-risk Drug Users

ABSTRACT The use of synthetic cannabinoids receptor agonists (SCRA) and synthetic opioids is associated with significant morbidity and mortality. This study examined the patterns-of-use of prescription oral opioids or transdermal fentanyl formulations, and SCRA, among 342 patients enrolled in treatment for drug-dependence in Israel. 16.1% of participants reported recent (past-12 months) SCRA use, while 24.9% reported recent use of prescription oral opioids, transdermal fentanyl patches, or both. Odds of reporting recent use of SCRA were positively and significantly associated with reporting recent use of cannabis (Adjusted Odds Ratio [AOR] 9.86, 95% Confidence Interval [CI] 4.44–21.90) and synthetic cathinones (AOR 5.47, CI 2.50–11.96). Recent use of prescription oral opioids or transdermal fentanyl formulations use was positively and significantly associated with recent use of gabapentinoids (AOR 14.33, CI 7.10, 28.90), stimulants (AOR 7.12, CI 3.82,13.28), heroin (AOR 5.81, CI 3.39,9.97), benzodiazepines (AOR 4.63, CI 2.74,7.84), synthetic cathinones (AOR 4.12, CI 1.95, 8.70), and hallucinogens (AOR 2.48, CI 1.24, 2.96). Clinicians should be informed about the extent of prescription oral opioids or transdermal fentanyl formulations and SCRA use among high-risk drug users, and the associated higher odds of concomitantly using other psychoactive substance, for they represent actual risk to patients and complicate treatment.

Development and Validation of a Liquid Chromatography High-Resolution Mass Spectrometry (LC-HRMS) Bioanalytical Method for Quantifying Cannabinoids in Whole Blood: Application for Determining Recent Cannabis Use.

Cannabis legalization is expanding rapidly throughout the United States, but there is no reliable means of establishing recent use. To develop and validate a bioanalytical method for determination of Δ9-tetrahydrocannabinol (Δ9-THC), cannabinol, 11-hydroxy-Δ9-THC, 11-nor-9-carboxy-Δ9-THC, and 8β,11-dihydroxy-Δ9-THC in whole blood microsamples by liquid chromatography high-resolution mass spectrometry (LC-HRMS). Cannabinoid extraction from whole blood was performed using a mixture of n-hexane/ethyl acetate (90:10, v/v). Chromatographic separation was performed with a C18 column using a binary mobile phase gradient of water and acetonitrile, each with 0.1% formic acid. Detection was performed by positive ion mode heated electrospray ionization with full scan MS on an Orbitrap mass spectrometer. A clinical study was performed in 30 subjects to identify recent cannabis use based on analysis of cannabinoids in blood samples up to 200 min post-smoking. Acceptable linearity of all calibration curves was observed (r2>0.99) for all analytes over a 1-100 ng/mL concentration range, with acceptable accuracy. Limit of detection (LOD) was 0.5 ng/mL. Accuracy and precision met acceptance criteria for all analytes. Repeatability (CV) was <5% at low (3 ng/mL) and high (90 ng/mL) concentrations. In the clinical study, the ratios between 11-nor-9-carboxy-Δ9-THC and Δ9-THC fell immediately after smoking and returned to near baseline levels by 200 min post-smoking, which is consistent with recent use. The developed LC-HRMS bioanalytical method is suitable for quantification of five key cannabinoids in whole capillary blood microsamples and can be used in conjunction with a test for determining recent cannabis use.

Assessing adolescent tobacco use in a substance use treatment program with self-report and biological measures

Tobacco use in adolescents can alter their lifetime health outcomes. Despite the importance of early identification and treatment, adolescent tobacco use, including that of electronic vapor products (e.g., e-cigarettes), is often missed. In a state-funded substance use treatment program, we added biological measures, including urinary cotinine and exhaled carbon monoxide to self-report measures to assess recent and lifetime tobacco use. We conducted a retrospective review of the de-identified charts to examine the feasibility of screening for self-report and biological measures of tobacco use. Self-report, urinary cotinine, and exhaled carbon monoxide samples were obtained at every visit, including intake and follow-up. There were 52 adolescents with a total of 400 clinic visits to the program. Of those 400 visits, 258 included self-reported tobacco use and 142 included a denial of using any form of tobacco. However, of those 142 visits with a negative self-report of tobacco, 31 tested positive for cotinine and 6 had positive exhaled carbon monoxide. Although 111 of the 142 had negative cotinine, 5 had positive carbon monoxide, but all of those self-reported recent cannabis use. Despite using a sensitive measure of self-report of tobacco use, almost 22% of visits had a discordant self-report with a biological measure that indicated tobacco use. Considering the lifelong impact of adolescent tobacco use, clinicians should consider augmenting self-report with biological measures of tobacco use. Identification of tobacco use in adolescents with substance use can assist clinicians in providing education about tobacco use, such as electronic vapor products, and individualizing treatments.

Associations between Recent and Cumulative Cannabis Use and Internalizing Problems in Boys from Adolescence to Young Adulthood.

This study tested whether increases in recent and cumulative cannabis use were each associated with increases in internalizing problems from adolescence to young adulthood. Participants were boys from a community sample that was assessed annually from ~age 15-26 (N = 506). Boys reported on their cannabis use, depression symptoms, and anxiety/depression problems each year. Exposures were frequency of cannabis use in a given year (no use, < weekly use, weekly or more frequent use) and cumulative prior years of weekly cannabis use. Outcomes were depression symptoms and anxiety/depression problems in a given year. Analyses examined within-person associations between changes in exposures and outcomes over time, which eliminated "fixed" (unchanging) individual differences as potential confounds. Analyses also accounted for time-varying factors as potential confounds (other substance use, externalizing problems, subclinical psychotic symptoms). Results showed that increases in recent cannabis use and cumulative prior years of weekly cannabis use were each associated with increases in depression symptoms and anxiety/depression problems. After controlling for time-varying covariates, increases in cumulative prior years of weekly cannabis use, but not recent cannabis use, remained associated with increases in depression symptoms and anxiety/depression problems. Specifically, each additional year of prior weekly cannabis use was associated with a small increase in depression symptoms (b =0.012, p = .005) and anxiety/depression problems (b =0.009, p = .001). Associations did not vary systematically across time. There was also no evidence of reverse causation. As boys engaged in weekly cannabis use for more years, they showed increases in internalizing problems, suggesting the importance of preventing chronic weekly cannabis use.

Recent cannabis use is associated with smaller hippocampus volume: High-resolution segmentation of structural subfields in a large non-clinical sample.

There is mixed evidence that individuals who use cannabis have reduced hippocampal and amygdalar gray matter volume, potentially because of small sample sizes and imprecise morphological characterization. New automated segmentation procedures have improved the measurement of these structures and allow better examination of their subfields, which have been linked to distinct aspects of memory and emotion. The current study applies this new segmentation procedure to the Human Connectome Project Young Adult dataset (N = 1080) to investigate associations of cannabis use with gray matter volume in the hippocampus and amygdala. Results revealed significant bilateral inverse associations of hippocampal volume with recent cannabis use (THC+ urine drug screen; P < .005). Hippocampal subfield analyses indicated these associations were primarily driven by the head of the hippocampus, the first section of the cornu amonis (CA1), the subicular complex, and the molecular layer of the hippocampus. No associations were detected for age of cannabis initiation, the frequency of cannabis use across the lifespan, or the lifetime presence of cannabis use disorder. In one of the largest studies to date, these results support the hypothesis that recent cannabis use is linked to reduced hippocampal volume, but that this effect may dissipate following prolonged abstinence. Furthermore, these results clarify the specific subfields which may be most associated with recent cannabis use.

Fatty acid amide hydrolase is lower in young cannabis users.

We have recently shown that levels of fatty acid amide hydrolase (FAAH), the enzyme that metabolizes the endocannabinoid anandamide, are lower in the brains of adult cannabis users (CUs) (34 ± 11 years of age), tested during early abstinence. Here, we examine replication of the lower FAAH levels in a separate, younger cohort (23 ± 5 years of age). Eighteen healthy volunteers (HVs) and fourteen CUs underwent a positron emission tomography scan using the FAAH radioligand [11 C]CURB. Regional [11 C]CURB binding was calculated using an irreversible two-tissue compartment model with a metabolite-corrected arterial plasma input function. The FAAH C385A genetic polymorphism (rs324420) was included as a covariate. All CUs underwent a urine screen to confirm recent cannabis use and had serum cannabinoids measured. One CU screened negative for cannabinoids via serum and was removed from analysis. All HVs reported less than five lifetime cannabis exposures more than a month prior to study initiation. There was a significant effect of group (F1,26 = 4.31; P = .048) when two A/A (rs324420) HVs were removed from analysis to match the genotype of the CU group (n = 16 HVs, n = 13 CUs). Overall, [11 C]CURB λk3 was 12% lower in CU compared with HV. Exploratory correlations showed that lower brain [11 C]CURB binding was related to greater use of cannabis throughout the past year. We confirmed our previous report and extended these findings by detecting lower [11 C]CURB binding in a younger cohort with less cumulative cannabis exposure.

Known fentanyl use among clients of harm reduction sites in British Columbia, Canada

BackgroundNorth America is in the midst of an opioid overdose epidemic and it is commonly suggested that exposure to fentanyl is unknown. Using a provincial survey of harm reduction site clients, we aimed to characterize known and unknown fentanyl use and their correlates among people who use drugs in British Columbia, Canada. MethodsWe recruited 486 clients who were >18 years old and 316 agreed to provide a urine sample for substance use testing. Reported known fentanyl use was defined as a three-level categorical variable assessing recent (i.e., in the previous three days) fentanyl exposure: (i) known exposure; (ii) unknown exposure; and (iii) no exposure. We also assessed any exposure to fentanyl (Yes vs. No) confirmed by urinalysis. Survey data were summarized using descriptive statistics. Multinomial logistic regression and modified Poisson regression models were built to examine different correlates of exposure to fentanyl. ResultsMedian age of the participants was 40 (IQR: 32–49). Out of the 303 eligible participants, 38.7% (117) reported known fentanyl use, 21.7% (66) had unknown fentanyl use, and 39.6% (120) had no recent fentanyl use. In the adjusted multinomial logistic regression model and in comparison with unknown fentanyl use, recent known fentanyl use was significantly associated with self-report of methadone use (aRRR = 3.18), heroin/morphine use (aRRR = 4.40), and crystal meth use (aRRR = 2.95). Moreover, any recent exposure to fentanyl (i.e., positive urine test for fentanyl) was significantly associated with living in urban settings (aPR = 1.49), and self-reporting recent cannabis use (aPR = 0.73), crystal meth (aPR = 1.45), and heroin/morphine use (aPR = 2.48). ConclusionThe landscape of illicit opioid use is changing in BC and more people are using fentanyl knowingly. The increasing prevalence of known fentanyl use is concerning and calls for further investments in public awareness and public policy efforts regarding fentanyl exposure and risks.

Association Between Recent Cannabis Consumption and Withdrawal-Related Symptoms During Early Abstinence Among Females With Smoked Cocaine Use Disorder.

The effects of cannabis on clinical outcomes of treatment services for other drug use disorders remains unclear. The primary aim of the current study was to investigate the effects of recent cannabis consumption on the severity of cocaine withdrawal and depressive symptoms during a 3-week inpatient treatment program for women with cocaine use disorder. The second goal of this study was to test the effect of recent alcohol or tobacco use on the aforementioned outcomes. This was a longitudinal study with 2 assessment time points: at enrollment and upon discharge from a medically managed intensive inpatient unit. The sample was composed of 214 early abstinence females with cocaine use disorder. Cocaine withdrawal and depressive symptoms were measured using the Cocaine Selective Severity Assessment (CSSA) and the Beck Depressive Inventory (BDI-II). Recent substance use was evaluated using the Addiction Severity Index (ASI-6). Patients with cocaine use disorder and with frequent recent cannabis use reported higher severity of cocaine withdrawal and depressive symptoms after 3 weeks of inpatient treatment. Neither recent alcohol nor tobacco use was associated with increased CSSA or BDI outcomes, suggesting these substances play a minor role compared to recent cannabis use in affecting withdrawal-related symptoms. The assessment of recent cannabis use may help identify patients in need of additional treatment to manage severe cocaine withdrawal symptoms and depressive symptoms during early abstinence.

Impact of Cannabis Use on Brain Structure and Function in Suppressed HIV Infection

Brain atrophy and cognitive deficits persist among individuals with suppressed HIV disease. The impact of cannabis use is unknown. HIV+ and HIV- participants underwent cross-sectional magnetic resonance imaging and neuropsychological testing. Lifetime frequency, duration (years), and recency of cannabis use were self-reported. Relationships of cannabis use to resting-state functional connectivity (RSFC) and to 9 regional brain volumes were assessed with corrections for multiple comparisons. Peripheral blood cytokines and monocyte subsets were measured in the HIV+ group and examined in relation to cannabis exposure. We evaluated 52 HIV+ [50.8 ± 7.1 years old; 100% on antiretroviral therapy ≥ 3 months; 83% with plasma viral load < 50 copies/mL] and 55 HIV- [54.0 ± 7.5 years old] individuals. Among HIV+ participants, recent cannabis use (within 12 months) was associated with diminished RSFC, including of occipital cortex, controlling for age. Duration of use correlated negatively with volumes of all regions (most strikingly the nucleus accumbens) independently of recent use and intracranial volume. Recent use was associated with larger caudate and white matter volumes and lower soluble vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1 concentrations. Duration of use correlated positively with psychomotor speed. Use > 10 times/lifetime was linked to more somatic symptoms, better executive function, and lower CD14+CD16++ monocyte count. HIV+ individuals demonstrated opposing associations with cannabis. Recent use may weaken RSFC and prolonged consumption may exacerbate atrophy of the accumbens and other brain regions. More frequent or recent cannabis use may reduce the inflammation and CD14+CD16++ monocytes that facilitate HIV neuroinvasion. HIV-specific cannabis studies are necessary.

Acute myocardial infarction associated with cannabis use

Cannabis is one of the most widely used illicit substances worldwide, and it has the highest prevalence among drugs used in our country in young adults. Yet its potential cardiovascular consequences are not fully understood. Highlighting the demographic, clinical presentation, laboratory results and angiographic characteristics of patients with type 1 myocardial infarction (MI) with a history of cannabis use. Retrospective chart review of patients with MI presenting to our Intensive Coronary Care Unit over a period of 4 years (January 2014–December 2018), and who reported the recent use of cannabis and other substances. No toxicological screen was performed. Of the 14 case subjects studied who presented with chest pain, mean age at presentation was 40.1 ± 9.7 (years) SD. There were 13 males and one female. All patients were tobacco smokers, 4 patients (28%) had a history of diabetes and no history of dyslipidemia and hypertension was noted in all patients. All patients used Cannabis (100%), 14% cocaine and 28% alcohol. At presentation, 11 patients (78%) had an EKG evidences of ST-segment elevation MI (STEMI), two of them were transient. Complete atrioventricular block was found in one case. Troponin I (hs cTnI) peak mean level was 13000 ± 23511 ng/ml. All patients underwent coronary angiography and 9 of them had angiographic evidence of single vessel obstructive coronary artery disease. Left ventricular ejection fraction (EF) as determined by cardiac echocardiogram ranged from 15% to 70%, with a mean of 47% ± 15%. In our study, Cannabis use is associated with MI, occurring at a relatively younger age with half of the cases either low risk or CVD risk free. Additional studies are needed to further characterize this population given the increase in marijuana use.

Factor Structure of the Cannabis Use Disorders Identification Test Revised (CUDIT-R) for Men and Women.

The Cannabis Use Disorders Identification Test Revised (CUDIT-R) is an 8-item screening instrument designed to identify recent problematic cannabis use over the past 6 months. The purpose of the present study was to investigate the factor structure of the CUDIT-R separately for male and female college students. Participants included 1,390 male and female college students recruited from three state universities (61% female; Age: M= 19.8, SD= 1.3). We conducted exploratory and confirmatory factor analyses followed by tests of measurement invariance including configural invariance, metric invariance and scalar invariance across men and women. Results confirmed a one-factor structure for the CUDIT-R. The number of factors and item loadings were invariant between men and women. However, intercepts were non-invariant for an item asking about consumption of cannabis use indicating that the endorsement of this item varied between men and women. Follow-up validation tests indicated that using a sum score for analyses is appropriate despite non-invariance. However, more research is needed to determine if the cut-off scores of the CUDIT-R should be reevaluated by gender.

Exposure to Cannabis Marketing in Social and Traditional Media and Past-Year Use Among Adolescents in States With Legal Retail Cannabis.

The objective of this study was to examine adolescents' self-reported exposure to cannabis marketing in states with legalized cannabis and its association with past-year cannabis use. We conducted a cross-sectional, online panel survey of 469 adolescents aged 15-19years residing in four states with legal retail cannabis for adult use. Adolescents self-reported exposure to cannabis marketing on social or traditional media (i.e., outdoor or print) and past-year cannabis use. Logistic regression generated estimated odds of youths' past-year cannabis use by marketing exposure after adjusting for demographic factors and cannabis-related social norms. Exposure to cannabis marketing on Facebook, Twitter, and Instagram was associated with increased odds of past-year cannabis use of 96% (95% confidence interval [CI]: 15%-234%), 88% (95% CI: 11%-219%), and 129% (95% CI: 32%-287%), respectively. Odds of past-year cannabis use increased by 48% (95% CI: 16%-87%) with each additional social media platform where adolescents reported exposure. Despite restrictions that prohibit cannabis advertising on social media, adolescents are exposed to cannabis marketing via social media, and this exposure is associated with recent cannabis use. States should consider further regulation of cannabis marketing on social media.

Subjective effects of combustible, vaporized, and edible cannabis: Results from a survey of adolescent cannabis users

BackgroundData from controlled laboratory experiments in adults indicate that the subjective effects of cannabis vary by administration method (e.g., combustible, vaporized). Whether the subjective effects of cannabis experienced in the natural ecology and among adolescents differ by cannabis administration method is unknown. In this observational study, adolescents’ retrospective reports of subjective effects after combustible, edible, and vaporized cannabis use were examined. MethodsStudents from ten public schools in Los Angeles, CA, USA (M[SD] age = 16.1 [.43] years) who reported past 6-month use of combustible, edible, or vaporized cannabis (N = 584) were surveyed on subjective effects experienced after use (yes/no). They were provided with a 12 item self-report checklist of six positive (e.g., relaxed, energetic) and six negative (e.g., drowsy, lazy) subjective effects. For each method of administration, affirmative responses were summed in positive (range: 0–6) and negative (range: 0–6) effect composite scores. ResultsGeneralized estimating equations adjusted for demographics and recent cannabis use revealed a graded pattern of differences in positive subjective effects across products, with highest scores for combustible (M[SD] = 3.98[1.76]), followed by edible (M[SD] = 3.58 [2.04]) and vaporized (M[SD] = 3.11 [2.21]) cannabis (all pairwise cross-product contrasts p < .01). Mean negative effect score was highest for edible (M[SD] = 2.27 [1.95]), followed by combustible (M[SD] = 1.94 [1.66]), and vaporized (M[SD] = 1.34 [1.73]) cannabis, respectively (all pairwise contrasts p < .02). ConclusionAdolescents’ reports of subjective effects varied across cannabis administration methods. Combustible cannabis’ more desirable subjective effects profile might be indicative of higher abuse liability.

Cannabis involvement and neuropsychological performance: findings from the Human Connectome Project

There is evidence that heavy cannabis use is associated with decrements in cognitive performance, but findings are mixed and studies are often limited by small sample sizes and narrow adjustment for potential confounding variables. In a comparatively large sample, the current study examined associations between multiple indicators of cannabis use in relation to performance on a variety of neuropsychological tasks. Participants were 1121 adults (54% female) enrolled in the Human Connectome Project. Cannabis involvement comprised recent cannabis use (positive tetrahydrocannabinol screen), total number of lifetime uses, cannabis use disorder and age at first use. The neuropsychological battery comprised performance in episodic memory, fluid intelligence, attention, working memory, executive function, impulsive decision-making, processing speed and psychomotor dexterity. Covariates were age, sex, income, family structure and alcohol and tobacco use. Positive urinary tetrahydrocannabinol status was associated with worse performance in episodic memory and processing speed, and positive cannabis use disorder status was associated with lower fluid intelligence (all p < 0.005). No other significant associations were present. The sample was limited to young adults aged 22–36 years. The measures of cannabis involvement were relatively coarse. Beyond an array of potential confounders, recent cannabis use was associated with deficits in memory and psychomotor performance, and cannabis use disorder was associated with lower overall cognitive functioning in a large normative sample of adults. The findings pertaining to recent use have particular relevance for occupational settings.

Recent tobacco use has widespread associations with adolescent white matter microstructure

ImportanceGiven the prevalence of alcohol, cannabis, and tobacco use during adolescence, it is important to explore the relative relationship of these three substances with brain structure. ObjectiveTo determine associations between recent alcohol, cannabis, and tobacco use and white and gray matter in a large sample of adolescents. Design, Setting, and ParticipantsMRI data were collected in N = 200 adolescents ages 14–18 (M = 15.82 years; 67% male; 61% Hispanic/Latino). On average, during the past month, participants reported consuming 2.05 drinks per 1.01 drinking day, 0.64 g per 6.98 cannabis use days, and 2.49 cigarettes per 12.32 smoking days. Main Outcomes and MeasuresGeneral linear models were utilized to examine past 30-day average quantities of alcohol, cannabis, and tobacco use, age, sex, and sex by substance interactions in skeletonized white matter (fractional anisotropy and axial, radial, and mean diffusivity) and voxel-based morphometry of gray matter (volume/density). ResultsTobacco use was negatively associated with white matter integrity (radial and mean diffusivity) with peak effects in inferior and superior longitudinal fasciculi. Cannabis use was negatively associated with white matter integrity (axial diffusivity) in a small cluster in the left superior longitudinal fasciculus. No associations were observed between recent alcohol use and white or gray matter overall, but interactions showed significant negative associations between alcohol use and white matter in females. Conclusions and RelevanceIt is important to note that recent tobacco use, particularly given the popularity of e-tobacco/vaping in this age group, had widespread associations with brain structure in this sample of adolescents.

Detection of Δ9 THC in oral fluid following vaporized cannabis with varied cannabidiol (CBD) content: An evaluation of two point-of-collection testing devices.

Point‐of‐collection testing (POCT) for Δ9‐tetrahydrocannabinol (THC) in oral fluid is increasingly used to detect driving under the influence of cannabis (DUIC). However, previous studies have questioned the reliability and accuracy of two commonly used POCT devices, the Securetec DrugWipe® 5 s (DW5s) and Dräger DrugTest® 5000 (DT5000). In the current placebo controlled, double‐blind, crossover study we used liquid chromatography‐tandem mass spectrometry (LC–MS/MS) to accurately quantify cannabinoid concentrations in the oral fluid of 14 participants at various timepoints (10, 60, 120, and 180 minutes) following vaporization of 125 mg of THC‐dominant (11% THC; <1% CBD), THC/CBD equivalent (11% THC; 11% CBD) and placebo (<1% THC; <1% CBD) cannabis. At each timepoint, oral fluid was also screened using the DW5s (10 ng/mL THC cut‐off) and DT5000 (10 ng/mL THC cut‐off). LC–MS/MS analysis showed peak oral fluid THC concentrations at the 10 minute timepoint with a rapid decline thereafter. This trajectory did not differ with THC dominant and THC/CBD equivalent cannabis. With a 10 ng/mL confirmatory cut‐off, 5% of DW5s test results were false positives and 16% false negatives. For the DT5000, 10% of test results were false positives and 9% false negatives. Neither the DW5s nor the DT5000 demonstrated the recommended >80% sensitivity, specificity and accuracy. Accuracy was lowest at 60 minutes, when THC concentrations were often close to the screening cut‐off (10 ng/mL). POCT devices can be useful tools in detecting recent cannabis use; however, limitations should be noted, and confirmatory LC–MS/MS quantification of results is strongly advisable.

Detectability of various cannabinoids in plasma samples of cannabis users: Indicators of recent cannabis use?

To assess the informative value of determining (minor) cannabinoids in plasma of cannabis users, detection rates of 14 cannabinoids (next to Δ9 -THC and THC-COOH) were determined. 11-OH-THC, THCA, CBC, CBN, and CBD were the most frequent detectable cannabinoids. The dependency of cannabinoid detectability on the plasma Δ9 -THC concentration was examined.

Specificity of personality relationships to particular forms of concurrent substance use among methadone maintenance therapy clients

ObjectiveA mainstay treatment for opioid addiction in North America is methadone maintenance therapy (MMT) – a form of opiate agonist therapy (OAT). While efficacious for treating opioid addiction, MMT fails to address the concurrent polysubstance use that is common among opioid dependent clients. Moreover, psychosocial approaches for addressing polysubstance use during MMT are lacking. Our study's goals were to validate the use of the four-factor personality model of substance use vulnerability in MMT clients, and to demonstrate theoretically-relevant relationships of personality to concurrent substance use while receiving MMT. MethodRespondents included 138 daily-witnessed MMT clients (65.9% male, 79.7% Caucasian), mean age (SD) 40.18 (11.56), recruited across four Canadian MMT clinics. Bayesian confirmatory factor analysis was used to establish the structural validity of the four-factor personality model of substance use vulnerability (operationalized with the Substance Use Risk Profile Scale [SURPS]) in MMT clients. SURPS personality scores were then used as predictors for specific forms of recent (past 30-day) substance use. ResultsUsing a latent hierarchal model, hopelessness was associated with recent opioid use; anxiety sensitivity with recent tranquilizer use; and sensation seeking with recent alcohol, cannabis, and stimulant use. ConclusionPersonality is associated with substance use patterns and may be an appropriate target for intervention for those undergoing MMT to reduce opioid use, and potentially dangerous concurrent use of other drugs, while receiving methadone.