Acute Cannabis Use Research Articles

Recent Perceived Stress, Amygdala Reactivity to Acute Psychosocial Stress, and Alcohol and Cannabis Use in Adolescents and Young Adults With Bipolar Disorder.

Background: Psychosocial stress negatively affects the clinical course of bipolar disorder. Studies primarily focused on adults with bipolar disorder suggest the impact of stress is progressive, i.e., stress response sensitizes with age. Neural mechanisms underlying stress sensitization are unknown. As stress-related mechanisms contribute to alcohol/substance use disorders, variation in stress response in youth with bipolar disorder may contribute to development of co-occurring alcohol/substance use disorders. This study investigated relations between psychosocial stress, amygdala reactivity, and alcohol and cannabis use in youth with bipolar disorder, compared to typically developing youth.Methods: Forty-two adolescents/young adults [19 with bipolar disorder, 23 typically developing, 71% female, agemean ± SD = 21 ± 2 years] completed the Perceived Stress Scale (PSS), Daily Drinking Questionnaire modified for heaviest drinking week, and a modified Montreal Imaging Stress functional MRI Task. Amygdala activation was measured for both the control and stress conditions. Main effects of group, condition, total PSS, and their interactions on amygdala activation were modeled. Relationships between amygdala response to acute stress with recent alcohol/cannabis use were investigated.Results: Greater perceived stress related to increased right amygdala activation in response to the stress, compared to control, condition in bipolar disorder, but not in typically developing youth (group × condition × PSS interaction, p = 0.02). Greater amygdala reactivity to acute stress correlated with greater quantity and frequency of alcohol use and frequency of cannabis use in bipolar disorder.Conclusion: Recent perceived stress is associated with changes in amygdala activation during acute stress with amygdala reactivity related to alcohol/cannabis use in youth with bipolar disorder.

Simulated driving performance among daily and occasional cannabis users

ObjectiveDaily cannabis users develop tolerance to some drug effects, but the extent to which this diminishes driving impairment is uncertain. This study compared the impact of acute cannabis use on driving performance in occasional and daily cannabis users using a driving simulator. MethodsWe used a within-subjects design to observe driving performance in adults age 25 to 45 years with different cannabis use histories. Eighty-five participants (43 males, 42 females) were included in the final analysis: 24 occasional users (1 to 2 times per week), 31 daily users and 30 non-users. A car-based driving simulator (MiniSim™, National Advanced Driving Simulator) was used to obtain two measures of driving performance, standard deviation of lateral placement (SDLP) and speed relative to posted speed limit, in simulated urban driving scenarios at baseline and 30 min after a 15 min ad libitum cannabis smoking period. Participants smoked self-supplied cannabis flower product (15% to 30% tetrahydrocannabinol (THC). Blood samples were collected before and after smoking (30 min after the start of smoking). Non-users performed the same driving scenarios before and after an equivalent rest interval. Changes in driving performance were analyzed by repeated measures general linear models. ResultsMean whole blood THC cannabinoids concentrations post smoking were use THC = 6.4 ± 5.6 ng/ml, THC-COOH = 10.9 ± 8.79 ng/mL for occasional users and THC = 36.4 ± 37.4 ng/mL, THC-COOH = 98.1 ± 90.6 ng/mL for daily users. On a scale of 0 to 100, the mean post-use score of subjective high was similar in occasional users and daily users (52.4 and 47.2, respectively). In covariate-adjusted analysis, occasional users had a significant increase in SDLP in the straight road segment from pre to post compared to non-users; non-users decreased by a mean of 1.1 cm (25.5 cm to 24.4 cm) while occasional users increased by a mean of 1.9 cm (21.7 cm to 23.6 cm; p = 0.02). Daily users also increased adjusted SDLP in straight road segments from baseline to post-use (23.2 cm to 25.0 cm), but the change relative to non-users was not statistically significant (p = 0.08). The standardized mean difference in unadjusted SDLP from baseline to post-use in the straight road segments comparing occasional users to non-users was 0.64 (95% CI 0.09 – 1.19), a statistically significant moderate increase. When occasional users were contrasted with daily users, the baseline to post changes in SDLP were not statistically significant. Daily users exhibited a mean decrease in baseline to post-use adjusted speed in straight road segments of 1.16 mph; a significant change compared to slight speed increases in the non-users and occasional users (p = 0.02 and p = 0.01, respectively). ConclusionWe observed a decrement in driving performance assessed by SDLP after acute cannabis smoking that was statistically significant only in the occasional users in comparison to the nonusers. Direct contrasts between the occasional users and daily users in SDLP were not statistically significant. Daily users drove slower after cannabis use as compared to the occasional use group and non-users. The study results do not conclusively establish that occasional users exhibit more driving impairment than daily users when both smoke cannabis ad libitum.

Impact of Acute and Chronic Cannabis Use on Stress Response Regulation: Challenging the Belief That Cannabis Is an Effective Method for Coping

Although research has only recently started to examine the impact of cannabis use on stress response, there is some evidence that indicates acute and chronic impacts of cannabis on these processes. In this paper, we review processes involved in regulating the stress response and we review the influence of acute and chronic exposure to cannabis on patterns and regulation of the stress response. We also highlight the role of stress as a risk factor for initiation and maintenance of cannabis use. In this context, we examine moderating variables, including sex and life adversity. In light of recent observations indicating increasing prevalence of cannabis use during pregnancy, we provide additional focus on cannabis use in this vulnerable population, including how acute and chronic stress may predispose some individuals to use cannabis during pregnancy. While this line of research is in its infancy, we review available articles that focus on the perinatal period and that examined the association between cannabis use and various life stressors, including partner violence, job loss, and lack of housing. We also review psychiatric co-morbidities (e.g., post-traumatic stress disorder, anxiety). A better understanding of the way stress and cannabis use relate within the general population, as well as within certain subgroups that may be at a greater risk of using and/or at greater risk for adverse outcomes of use, may lead to the development of novel prevention and intervention approaches.

Heart Rate Variability is Altered in College‐Aged Chronic Cannabis Users versus Non‐Users

Cannabis is an increasingly popular recreational drug among college students. Prior investigations have shown that acute cannabis use alters heart rate variability via increased sympathetic activation. However, the effects of chronic cannabis use on heart rate variability (HRV) have not been reported. PURPOSE We tested the hypothesis that HRV would be lower in chronic cannabis users (THC) compared to non-users (CON). METHODS Eleven cannabis users (age: 21±2 y, 2 females) and six controls (age: 20±2 y; 4 females) completed one study visit. Participants in the THC group self-reported using cannabis at least once per week for the past year or more. Participants in the CON reported to not use for 6 months prior to enrollment. Participants were instructed to abstain from alcohol for 24 h and cannabis for 72 h prior to the study visit. After 10 minutes of supine rest, heart rate (5-lead electrocardiogram) was continuously recorded at 1 kHz for 5 minutes of supine rest while participants breathed spontaneously. HRV was assessed using linear analysis via Fast Fourier transformation and non-linear analysis via Poincare plots. The root mean square of successive differences (RMSSD), percent of R-R intervals that differ by more than 50 ms (pRR50), and the standard deviation of R-R intervals (SDRR) were calculated to assess HRV in the time-domain. Fast Fourier transformation was used to assess HRV in the frequency domain (low-frequency (LF) and high-frequency (HF) power). Non-linear HRV analysis was performed using Poincare plots to calculate standard deviation 1 (SD1) and 2 (SD2). We used one-tailed unpaired t-tests to determine if the main outcome variables were different between groups. Values are reported as mean ± SD. RESULTS RRI was lower in THC (THC: 917±109 vs. CON: 1018±141 ms; P=0.06). RMSSD was lower in THC (THC: 57±21 vs. CON: 74±24 ms; P=0.07). There was no difference between groups for pRR50 (THC: 36±20 vs. CON: 47±21 %; P=0.12) or SDRR (THC: 68±16 vs. CON: 78±24 ms; P=0.15). LF power was not different between groups (THC: 1105±850 vs. CON: 1321±852 ms2; P=0.31), but HF power was lower in THC (THC: 1353±925 vs. CON: 2256±1195 ms2; P=0.05). SD1 was lower in THC (THC: 40±15 vs. CON: 53±17 ms; P=0.07). SD2 was not different between groups (THC: 86±19 vs. CON: 96±33 ms; P=0.23). CONCLUSION These preliminary data indicate that college-aged adults who regularly use cannabis have lower heart rate variability than their non-cannabis user counterparts. Based on linear and non-linear analyses, it appears that cannabis users have altered cardiac vagal activity at rest. However, more research is warranted to determine if cannabis use alters autonomic function and reactivity.

Altered fronto-occipital connectivity during visual selective attention in regular cannabis users

Cognitive processing impairments have been associated with acute cannabis use, but there is mixed evidence regarding the cognitive effects of chronic cannabis use. Several neuroimaging studies have noted selective-attention processing differences in those who chronically use cannabis, but the neural dynamics governing the altered processing is unclear. Twenty-four adults reporting at least weekly cannabis use in the past 6months on the Cannabis Use Disorder Identification Test - Revised were compared to 24 demographically matched controls who reported no prior cannabis use. All participants completed a visual selective attention processing task while undergoing magnetoencephalography. Time-frequency windows of interest were identified using a data-driven method, and spectrally specific neural activity was imaged using a beamforming approach. All participants performed within normal range on the cognitive task. Regular cannabis users displayed an aberrant cognitive interference effect in the theta (4-8Hz) frequency range shortly after stimulus onset (i.e., 0-250ms) in the right occipital cortex. Cannabis users also exhibited altered functional connectivity between the right prefrontal cortex and right occipital cortices in comparison to controls. Individuals with a history of regular cannabis use exhibited abnormal theta interference activity in the occipital cortices, as well as altered prefrontal-occipital functional connectivity in the theta range during a visual selective attention task. Such differences may reflect compensatory processing, as these participants performed within normal range on the task. Understanding the neural dynamics in chronic, regular cannabis users may provide insight on how long-term and/or frequent use may affect neural networks underlying cognitive processes.

Impact of cannabis and low alcohol concentration on divided attention tasks during driving

Objective To assess divided-attention performance when driving under the influence of cannabis with and without alcohol. Three divided-attention tasks were performed following administration of placebo, cannabis, and/or alcohol. Methods Healthy adult cannabis users participated in 6 sessions, receiving combinations of cannabis (placebo/low-THC/high-THC) and alcohol (placebo/active) in randomized order, separated by washout periods of ≥1 week. At 0.5 hours post-dosing, participants performed simulator drives in the University of Iowa National Advanced Driving Simulator (NADS-1), a full vehicle cab simulator with a 360° horizontal field of view and motion base that provides realistic feedback. Drives contained repeated instances of three tasks: a side-mirror task (reaction to a triangle appearing in the side-mirrors), an artist-search task (select a specified artist from a navigable menu on the vehicle’s console), and a message-reading task (read aloud a message displayed on the console). Blood THC and breath alcohol concentration (BrAC) were interpolated using individual power curves from samples collected approximately 0.17, 0.42, 1.4, and 2.3 hours post-dose. Driving measures during tasks were compared to equal-duration control periods occurring just prior to the task. Performance shifts, task completion, and lane departures were modeled relative to blood THC and BrAC using mixed-effects regression models. Results Each 1 µg/L increase in blood THC concentration predicted increased odds of failing to complete the artist-search task (OR: 1.05, 95% CI: 1.01-1.11, p = 0.046), increased odds of selecting at least one incorrect response (OR: 1.05, 95% CI: 1.00-1.09, p = 0.041), declines in speed during the side-mirror task (0.005 m/s, 95% CI: 0.001-0.009, p = 0.023), and longer lane departure durations during the artist-search task (0.74% of task-period, 95% CI: 0.12-1.36 p = 0.020). BrAC (approximately 0.05%) was not associated with task performance, though each 0.01 g/210 L increase predicted longer departure durations during the side-mirror task (1.41% of task-period, 95% CI: 0.08-2.76, p = 0.040) and increased standard deviation of lane position in the message-reading task (0.61 cm, 95% CI: 0.14-1.08, p = 0.011). Conclusions With increasing medical and legal cannabis use, understanding the impact of acute cannabis use on driving performance, including divided-attention, is essential. These data indicate that impaired divided-attention performance is a safety concern.

Effects of High-Potency Cannabis on Psychomotor Performance in Frequent Cannabis Users.

Background: Recently increased access to cannabis products in the United States has been associated with increased rates of driving after cannabis use. Although numerous studies indicate that cannabis impairs psychomotor and neurocognitive functions that can affect driving ability, the determination of cannabis-impaired driving risk is complicated by the extent to which frequent cannabis users develop tolerance to THC's subjective, cognitive, and psychomotor effects, and by the fact that there is no validated behavioral or biological marker of recent cannabis use or cannabis-related impairment. This study examined the psychomotor impairment-related effects experienced by frequent cannabis users in Colorado after naturalistic consumption of smoked cannabis, both immediately and 1 h postuse. Results were then validated in a smaller replication sample from Washington state. Methods: In the primary Colorado study, participants (n=70) used the DRUID® mobile app, a brief measure of psychomotor and cognitive domains that are sensitive to the effects of cannabis. First, participants used DRUID to establish a sober baseline impairment score. During a second appointment, they used DRUID at three time points: preuse, immediately after acutely using cannabis, and 1 h postuse. In the Washington replication sample, participants (n=39) used DRUID before acute cannabis consumption and then every half hour for 2.5 h. Results: In both studies, peak DRUID impairment effects were seen immediately after cannabis use, with recovery of performance at 1 h postuse. Specifically, significant quadratic effects of time emerged for both studies (Colorado study: (β=-0.935, SE=0.204, p<0.001); Washington study: β=3.0299, SE=1.3085, p<0.01). Domain-specific effects were tested in the larger Colorado study and were observed for reaction time within a complex divided attention task and a postural-stability balance task. Conclusions: These findings demonstrate that psychomotor impairment emerges immediately after acute cannabis use even in regular users, but decreases significantly 1 h postuse. These results underscore the potential utility of the DRUID app for assessing acute cannabis-related psychomotor impairment. Further research is needed to explore whether the DRUID app and/or the specific psychomotor functions it assesses might serve as a tool for measuring cannabis-related driving impairment. Clinical trials registration number for the Colorado Study: NCT03522103.

Anxiolytic Effects of Cannabinoid Receptor Agonists in the Zebrafish Species, Danio rerio

As of July 2019, 34 states in the U.S. have legalized medical marijuana and an additional 12 have legalized “low THC, high cannabidiol (CBD)” substances (Hanson &amp; Garcia, 2019). While acute cannabis use has been associated with decreased anxiety levels, users have also experienced adverse side effects including increased anxiety, panic reactions, and psychotic symptoms (Hall &amp; Degenhardt, 2009). Plant‐derived pharmacological agents, like cannabis, can vary in quality and composition (and thus efficacy) due to a variety of environmental factors (Atanasov et. al. 2015). In order to use cannabinoids to treat anxiety safely, a synthetic cannabinoid that can produce consistent therapeutic (anxiolytic) effects without producing psychoactive effects is necessary. Zebrafish are an increasingly popular model organism used due to their high sensitivity to chemicals as absorbed through their gills and quantifiable behavioral phenotypes (Stewart 2014). Humans and zebrafish have comparable endocannabinoid pathways that each contain CB1 and CB2 receptors (Krug and Clark 2015). When observed in a Novel Dive Tank, anxiety levels in zebrafish can be quantified. Like humans, male and female zebrafish differ in hormonal composition and therefore respond to treatments differently. In this study, male and female zebrafish were treated with CB receptor agonists anandamide and WIN 55,212‐2 and CB2 inverse agonist JTE‐907 in order to model the how the endocannabinoid system influences anxiety. The reduced amount of time spent in the upper zone by the JTE + Anandamide treated fish, combined with the increased time classified as highly mobile, suggests that JTE‐907 had an anxiogenic effect. Significant anxiolytic effects were observed the WIN treatment group, particularly in male treated fish. These results suggest that male treated fish are more receptive to the anxiolytic effects of a non‐selective CB agonist such as WIN 55, 212. Future research with a water‐soluble CB1 inverse agonist could provide insight into the differing roles of CB1 and CB2 receptors in cannabis‐based treatments.

A multimodal investigation of cerebellar integrity associated with high-risk cannabis use.

With legalization efforts across the United States, cannabis use is becoming increasingly mainstream. Various studies have documented the effects of acute and chronic cannabis use on brain structure and cognitive performance, including within the frontal executive control network, but little attention has been given to the effects on the cerebellum. Recent evidence increasingly points to the role of the cerebellum in various nonmotor networks, and the cerebellum's expression of cannabinoid receptors may pose particular vulnerabilities to the consequences of cannabis use. Using a combined approach of resting-state functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), the present study aims to assess how cannabis use relates to the cerebellum's intrinsic functional connectivity and underlying white matter structure and whether these properties are associated with craving or severity of cannabis use. Resting-state fMRI and DTI data, as well as self-reports of substance use history, were analyzed from a sample of 26 adults at risk for cannabis use disorder (CUD) and an age- and sex-matched comparison group of 25 cannabis-naïve adults (control). Results demonstrated that individuals at risk for a CUD showed key differences in cerebellar functional connectivity, with specific impacts on the dorsal attention and default mode networks. In addition, group differences in white matter were localized to the middle cerebellar peduncle (MCP), with a relationship between lower MCP diffusivity and higher levels of self-reported craving. These findings lend further support to the cerebellum's role in key cognitive networks and potential consequences for substance use disorders.

Driving after cannabis use and compensatory driving behaviors among current cannabis users in Colorado

Epidemiologic data, largely from fatal crashes, have demonstrated a 2-fold increase in motor vehicle crash risk associated with acute cannabis use (Asbridge et al. 2012; Hartman and Huestis 2013). ...

Cannabis, alcohol and cigarette use during the acute post-concussion period

ABSTRACTObjective: To document the prevalence of acute post-concussion cannabis, alcohol and cigarette use and their association with clinical recovery and symptom burden.Methods: A prospective cohort study was conducted. Concussions were physician-diagnosed and presented to the emergency department and concussion clinic within 7 days post-injury. Participants were assessed weekly and followed for a minimum 4 weeks. A survival analysis (using physician-determined recovery to both cognitive and physical activities) in addition to a weekly symptom score analysis was conducted.Results: A total of 307 acute concussions with a mean age of 33.7 years (SD, 13.0) were included. Acute post-concussion cannabis, alcohol and cigarette use were identified in 43 (14.0%), 125 (40.7%) and 61 (19.9%) individuals. Acute cannabis, alcohol and cigarette use were not associated with recovery to cognitive (p > .05) or physical activity (p > .05). Acute cigarette use was associated with a higher unadjusted symptom severity score at week1 (p = .003). Acute cannabis use was associated with lower symptom severity scores at week-3 (p = .061) and week-4 (p = .029).Conclusion: In conclusion, cannabis, alcohol and cigarette use were prevalent in the acute period post-concussion; however, were not observed to impact recovery within the first 4 weeks post-injury. Amongst unrecovered individuals, acute cannabis use was associated with lower symptom burden, while cigarette use was associated with greater initial symptom burden.

31 The Relationship Between Acute Pancreatitis and Cannabis Use Before and After Recreational Legalization in Select States

INTRODUCTION: Cannabis is one of the most widely used illicit drugs in the United States. Its use has steadily increased over the last decade in part due to recreational legalization in select states. Concurrently, the prevalence of acute pancreatitis (AP) has increased, yet the etiology of many cases remains unknown. With the national trend toward increased cannabis use, we sought to determine if there was an association between cannabis use and admissions for AP after recreational cannabis was legalized. METHODS: State Inpatient Databases for Colorado and Washington were obtained before (2011) and after (2015) recreational cannabis legalization. For comparison, data from Arizona and Florida was also obtained in matching years to represent states that have not legalized recreational cannabis. These were reviewed using ICD-9 and 10 codes for acute pancreatitis, cannabis use, and other variables. Demographics (age, gender and race), comorbidities and hospital characteristics were analyzed. Multivariate comparisons were performed for AP to determine if prevalence has increased over this time period and to assess an association between AP and cannabis use. Significance was determined with a P &lt; 0.05. RESULTS: On univariate comparison, a significant increase was found for both cannabis use and admissions for AP in both legalized and non-legalized states from 2011 to 2015 (P &lt; 0.001 for all). Multivariable adjusted analysis for AP indicated an increased odds of presentation with AP in all four states over the study period [legalized: OR 1.07 (CI 1.04, 1.10); non-legalized: OR 1.09 (CI 1.08, 1.11); P &lt; 0.001]. However, cannabis users as a group had a lower odds of presentation with AP in Colorado [OR 0.78 (CI 0.72, 0.86); P &lt; 0.001] and in Washington [OR 0.90 (CI 0.82, 0.98; P &lt; 0.001]. CONCLUSION: Both cannabis use and AP increased in all states in 2015, after legalization of recreational cannabis. Interestingly, cannabis users appeared to have a decreased odds of AP in both Colorado and Washington. This suggests that although cannabis use and AP have increased from 2011 to 2015, cannabis legalization does not appear to account for the rise in AP. Further studies are needed to better clarify the role of cannabis use and other factors that have led to a rise in AP over recent years.

22 Association Between Acute Pancreatitis and Cannabis Use—A U.S. Population-Based Study

INTRODUCTION: Cannabis is the most frequently used illicit drug in the world. Increase use of marijuana had caused higher rates of cannabis-related adverse effects. This study aims to assess the cannabis use as an etiology of acute pancreatitis. METHODS: A retrospective analysis was conducted using the de-identified data from the national health database, the Healthcare Cost and Utilization Project (HCUP). We identified the hospital encounters for “cannabis use” using international classification of Diseases (ICD-9) diagnostic codes from 2011 to 2014. We assessed the incidence of acute pancreatitis in cannabis use patients and independent predictors of acute pancreatitis by multivariate analysis. P-values less than 0.05 indicated a statistically significant association. The odds ratio and 95% confidence interval were also calculated. Data were analyzed using SPSS. RESULTS: A total of 410385 cannabis use admissions were identified - 5469 (1.3%) acute pancreatitis with history of cannabis use (study group) and 404916 (98.7%) without acute pancreatitis in cannabis use population (control group). Comparing study group with control group, age - mean with standard deviation 39.8 + 11.81 yrs vs. 36.09 + 14.05 (P &lt; 0.001) , sex - male 3901 (71.3%) vs. 252486 (62.4%) (P &lt; 0.0001, Odds ratio [OR] = 1.50, Confidence interval (CI); 1.41–1.59), race - African American 1765 (32.3%) vs. 113524 (28%) (P &lt; 0.0001, OR = 1.22, CI; 1.15–1.30), smoking 3909 (71.5%) vs. 222558 (55%) (P &lt; 0.0001, OR = 2.05, CI; 1.93–2.18), Alcohol 1959 (35.8%) vs. 54876 (13.6%) (P &lt; 0.0001, OR = 3.56, CI; 3.37–3.77), acute pancreatitis 5469 (1.3%) vs. 4334 (0.7%) OR = 1.80 CI 1.73–1.87, P &lt; 0.001). The odds of developing acute pancreatitis among cannabis use patient was significantly higher (P &lt; 0.001, adjusted odds ratio [aOR] = 1.20, CI; 1.14–1.25) (shown in Figure 1). CONCLUSION: This study showed that up to 20% increased likelihood of acute pancreatitis among the cannabis use patients. Older age, male sex, African American race, alcohol, smoking and cannabis use showed greater odds of developing acute pancreatitis.

An overview of the adverse effects of cannabis use for Canadian physicians.

Cannabis is the most widely used illicit substance and one of the most commonly used psychoactive substances in the world, preceded only by alcohol, tobacco and caffeine. Recent changes in legislation regarding cannabis use in Canada and potential upcoming changes worldwide may have a further impact on the prevalence of cannabis use. Thus, it is critical to understand the risks and potential adverse health effects of acute and long-term cannabis use. Current literature is lacking in many areas surrounding cannabis use, and for the most part is unable to provide clear associations once confounding variables are considered. Here we provide a general overview of the history of cannabis, the physical and mental health consequences, and the risks to specific groups. A scoping search of published articles in PubMed from the start date (1946) until 2018. Current evidence supports an association between cannabis use and mild respiratory and cardiac effects, but no clear increased risk of cancer. Psychiatric disorders, including schizophrenia and anxiety, show associations with cannabis use; however, a causal effect of cannabis use is unclear. While no evidence for increased risk in pregnancy has been found, risk is still undetermined. Youth may be at a greater risk as earlier initiation of use increases the risk of adverse health effects. Overall, evidence for direct and long-term adverse effects of cannabis use is minimal and additional longitudinal studies will be required to better delineate unidentified effects.

Acute and long-term cannabis use among stimulant users: Results from CTN-0037 Stimulant Reduction Intervention using Dosed Exercise (STRIDE) Randomized Control Trial

AimsThe aim of this study was to examine the impact of vigorous intensity, high dose exercise (DEI) on cannabis use among stimulant users compared to a health education intervention (HEI) using data from the Stimulant Reduction Intervention using Dosed Exercise, National Institute of Drug Abuse National Drug Treatment Clinical Trials Network Protocol Number 0037 (STRIDE). MethodsAdults (N = 302) enrolled in the STRIDE randomized clinical trial were randomized to either the DEI or the HEI. Interventions included supervised sessions three times a week during the Acute phase (12 weeks) and once a week during the Follow-up phase (6 months). Cannabis use was measured at each assessment via Timeline Follow Back and urine drug screens. Cannabis use was compared between the groups during the Acute and Follow-up phases using both the intent-to-treat sample and a complier average causal effects (CACE) analysis. FindingsApproximately 43% of the sample reported cannabis use at baseline. The difference in cannabis use between the DEI and HEI groups during the Acute phase was not significant. During the Follow-up phase, the days of cannabis use was significantly lower among those in the DEI group (1.20 days) compared to the HEI group (2.15 days; p = 0.04). ConclusionsFor those who adhered to the exercise intervention, vigorous intensity, high dose exercise resulted in less cannabis use. Results suggest that there were no significant short-term differences in cannabis use between the groups. Further study on the long-term impact of exercise as a treatment to reduce cannabis use should be considered.

Is acute cannabis use associated with serious motor vehicle accidents?

Kootenai Clinic Family Medicine Residency, Coeur d'Alene, Idaho The authors declare no conflicts of interest.

Disturbances of postural sway components in cannabis users

IntroductionA prominent effect of acute cannabis use is impaired motor coordination and driving performance. However, few studies have evaluated balance in chronic cannabis users, even though density of the CB1 receptor, which mediates the psychoactive effects of cannabis, is extremely high in brain regions critically involved in this fundamental behavior. The present study measured postural sway in regular cannabis users and used rambling and trembling analysis to quantify the integrity of central and peripheral nervous system contributions to the sway signal. MethodsPostural sway was measured in 42 regular cannabis users (CB group) and 36 non-cannabis users (N-CB group) by asking participants to stand as still as possible on a force platform in the presence and absence of motor and sensory challenges. Center of pressure (COP) path length was measured, and the COP signal was decomposed into rambling and trembling components. Exploratory correlational analyses were conducted between sway variables, cannabis use history, and neurocognitive function. ResultsThe CB group had significantly increased path length and increased trembling in the anterior-posterior (AP) direction. Exploratory correlational analyses suggested that AP rambling was significantly inversely associated with visuo-motor processing speed. DiscussionRegular cannabis use is associated with increased postural sway, and this appears to be predominantly due to the trembling component, which is believed to reflect the peripheral nervous system’s contribution to the sway signal.

Cannabis: An Overview of its Adverse Acute and Chronic Effects and its Implications.

In many communities, cannabis is perceived as a low-risk drug, leading to political lobbying to decriminalise its use. Acute and chronic cannabis use has been shown to be harmful to several aspects of psychological and physical health, such as mood states, psychiatric outcomes, neurocognition, driving and general health. Furthermore, cannabis is highly addictive, and the adverse effects of withdrawal can lead to regular use. These in turn have adverse implications for public safety and health expenditure. Although the cannabinoid cannabidiol (CBD) has been shown to have positive health outcomes with its antioxidant, anticonvulsant, anti-inflammatory and neuroprotective properties, high-potency cannabis is particularly damaging due to its high tetrahydrocannabinol (THC), low CDB concentration. It is this high-potency substance that is readily available recreationally. While pharmaceutical initiatives continue to investigate the medical benefits of CDB, "medicinal cannabis" still contains damaging levels of THC. Altogether, we argue there is insufficient evidence to support the safety of cannabis and its subsequent legalisation for recreational use. Furthermore, its use for medicinal purposes should be done with care. We argue that the public conversation for the legalisation of cannabis must include scientific evidence for its adverse effects.

Effects of cannabis use on body mass, fasting glucose and lipids during the first 12 months of treatment in schizophrenia spectrum disorders

While acute cannabis use stimulates appetite, general population studies suggest that chronic use is associated with reduced risk of obesity and other cardiometabolic risk factors. In this study we investigated changes in body mass index (BMI), fasting blood glucose and lipids, and rates of metabolic syndrome risk factors in cannabis users vs. non-users in 109 minimally treated patients with first-episode schizophrenia, schizophreniform or schizo-affective disorder who were treated according to a standardized treatment regime with depot antipsychotic medication over 12 months. Participants underwent repeated urine toxicology tests for cannabis and those testing positive at any time during the study (n = 40), were compared with those who tested negative at all time points (n = 69). There was a significant group*time interaction effect (p = 0.002) with the cannabis negative group showing a greater increase in BMI than the cannabis positive group, after adjusting for age, sex, methamphetamine use and modal dose of antipsychotic. There were no group*time interaction effects for fasting blood glucose or lipids. Post hoc tests indicated significant increases in fasting blood glucose and triglycerides and a decrease in high-density lipoprotein cholesterol for the cannabis negative group, with no significant changes in the cannabis positive group. Rates of metabolic syndrome did not differ significantly between groups, although more cannabis negative patients had elevated waist-circumference at endpoint (p = 0.003). It may be that chronic cannabis use directly suppresses appetite, thereby preventing weight gain in users. However, other indirect effects such as dietary neglect and smoking may be contributory and could explain our findings.

Using Mismatch Negativity to Investigate the Pathophysiology of Substance Use Disorders and Comorbid Psychosis.

Substance use disorders (SUDs) have a devastating impact on society and place a heavy burden on health care systems. Given that alcohol, tobacco, and cannabis use have the highest prevalence, further understanding of the underlying pathophysiology of these SUDs is crucial. Electroencephalography is an inexpensive, temporally superior, and translatable technique which enables investigation of the pathobiology of SUDs through the evaluation of various event-related potential components, including mismatch negativity (MMN). The goals of this review were to investigate the effects of acute and chronic alcohol, tobacco, and cannabis use on MMN among nonpsychiatric populations and patients with comorbid psychosis. A literature search was performed using the database PubMed, and 36 articles met our inclusion and exclusion criteria. We found a pattern of attenuation of MMN amplitude among patients with alcoholism across acute and chronic alcohol use, and this dysregulation was not heritable. Reports were limited, and results were mixed on the effects of acute and chronic tobacco and cannabis use on MMN. Reports on comorbid SUDs and psychosis were even fewer, and also presented mixed findings. These preliminary results suggest that MMN deficits may be associated with SUDs, specifically alcohol use disorder, and serve as a possible biomarker for treating these common disorders.