Frequency of cannabis and illicit opioid use among people who use drugs and report chronic pain: A longitudinal analysis.

BACKGROUND:Ecological research suggests that increased access to cannabis may facilitate reductions in opioid use and harms, and medical cannabis patients describe the substitution of opioids with cannabis for pain management. However, there is a lack of research using individual-level data to explore this question. We aimed to investigate the longitudinal association between frequency of cannabis use and illicit opioid use among people who use drugs (PWUD) experiencing chronic pain. METHODS AND FINDINGS:This study included data from people in 2 prospective cohorts of PWUD in Vancouver, Canada, who reported major or persistent pain from June 1, 2014, to December 1, 2017 (n = 1,152). We used descriptive statistics to examine reasons for cannabis use and a multivariable generalized linear mixed-effects model to estimate the relationship between daily (once or more per day) cannabis use and daily illicit opioid use. There were 424 (36.8%) women in the study, and the median age at baseline was 49.3 years (IQR 42.3-54.9). In total, 455 (40%) reported daily illicit opioid use, and 410 (36%) reported daily cannabis use during at least one 6-month follow-up period. The most commonly reported therapeutic reasons for cannabis use were pain (36%), sleep (35%), stress (31%), and nausea (30%). After adjusting for demographic characteristics, substance use, and health-related factors, daily cannabis use was associated with significantly lower odds of daily illicit opioid use (adjusted odds ratio 0.50, 95% CI 0.34-0.74, p < 0.001). Limitations of the study included self-reported measures of substance use and chronic pain, and a lack of data for cannabis preparations, dosages, and modes of administration. CONCLUSIONS:We observed an independent negative association between frequent cannabis use and frequent illicit opioid use among PWUD with chronic pain. These findings provide longitudinal observational evidence that cannabis may serve as an adjunct to or substitute for illicit opioid use among PWUD with chronic pain

Effects of repeated morphine deprivation on operant responding in rats.

These studies determined the effects of repeated morphine deprivation on behavior maintained by various reinforcers in the rat. A morphine dosing schedule was designed and characterized to establish and maintain dependence while allowing for repeated observation of behavior during morphine deprivation-induced withdrawal. Self-administration of the mu-opioid agonist remifentanil was assessed in nondependent (morphine-naive) rats and compared with self-administration in morphine dependent and deprived groups. Morphine deprivation was found to enhance remifentanil self-administration. The selectivity of this effect was assessed by evaluating the effects of morphine deprivation on behavior maintained by cocaine and two food reinforcers. Deprivation did not alter cocaine self-administration; however, deprivation did enhance behavior maintained by both food reinforcers. The increase in food-maintained behavior observed in the deprived group was likely due to morphine induced food deprivation and consequent weight loss throughout the experiment. Finally, to further characterize morphine deprivation-induced changes on the reinforcing effectiveness of remifentanil, economic demand was determined in dependent and nondependent groups of rats. Compared with nondependent rats, morphine-deprived rats demonstrated less elastic demand for remifentanil indicating that deprivation increased its reinforcing effectiveness. These studies provide evidence that morphine dependence and deprivation enhances the reinforcing properties of remifentanil.Ph.D.Health and Environmental SciencesPharmacologyPsychobiologyPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/126394/2/3253247.pd

Sex-Dependent Effects of Cannabis and Cannabinoids: A Translational Perspective

Recent policy changes have led to significant increases in the use of cannabis for both medical and recreational purposes. Although men are more likely to endorse past month cannabis use and are more frequently diagnosed with Cannabis Use Disorder relative to women, a growing proportion of medical cannabis users are reported to be women. The increased popularity of cannabis for medical purposes and the narrowing gap in prevalence of use between men and women raises questions regarding sex-dependent effects related to therapeutic efficacy and negative health effects of cannabis and cannabinoids. The objective of this review is to provide a translational perspective on the sex-dependent effects of cannabis and cannabinoids by synthesizing findings from preclinical and clinical studies focused on sex comparisons of their therapeutic potential and abuse liability, two specific areas that are of significant public health relevance. Hormonal and pharmacological mechanisms that may underlie sex differences in the effects of cannabis and cannabinoids are highlighted

Considering abuse liability and neurocognitive effects of cannabis and cannabis-derived products when assessing analgesic efficacy: a comprehensive review of randomized-controlled studies

Background: Pain is the most frequent indication for which medical cannabis treatment is sought.Objectives: The clinical potential of cannabis and cannabis-derived products (CDPs) relies on their efficacy to treat an indication and potential adverse effects that impact outcomes, including abuse liability and neurocognitive effects. To ascertain the extent to which these effects impact therapeutic utility, studies investigating cannabis and CDPs for pain were reviewed for analgesic efficacy and assessments of abuse liability and neurocognitive effects.Methods: A comprehensive review of placebo-controlled studies investigating cannabis and CDP analgesia was performed. Methods and findings related to adverse effects, abuse liability, and neurocognitive effects were extracted.Results: Thirty-eight studies were reviewed; 29 assessed cannabis and CDPs for chronic pain, 1 for acute pain, and 8 used experimental pain tests. Most studies ascertained adverse effects through self-report (N = 27). Fewer studies specifically probed abuse liability (N = 7) and cognitive and psychomotor effects (N = 12). Many studies related to chronic and experimental pain (N = 18 and N = 5, respectively) found cannabis and CDPs to reduce pain. Overall, adverse effects were mild to moderate, and dose-related. Studies investigating the impact of cannabis and CDPs on abuse liability and neurocognitive endpoints were mostly limited to inhaled administration and confirmed dose-related effects.Conclusion: Few studies investigating cannabis and CDP analgesia assess abuse liability and cognitive endpoints, adverse effects that impact the long-term clinical utility of these drugs. Future studies should include these measures to optimize research and clinical care related to cannabis-based therapeutics

Changes in medical and non-medical cannabis use among United States adults before and during the COVID-19 pandemic

Background: During the SARS-CoV-2 pandemic, cannabis dispensaries in the United States (US) reported increased sales.Objectives: This study assessed changes in cannabis use before to during the pandemic; it was hypothesized that cannabis use increased during the pandemic.Methods: A US-based survey of adults assessed patterns of use before and during the pandemic. Participants recruited via social media from 8/2020 to 9/2020 self-reported medical and non-medical cannabis use. Use was categorized as ≤ monthly, weekly, and daily/almost daily; adjusted logistic regressions determined associations between cannabis use before the pandemic with change in frequency during the pandemic.Results: Of 1,886 respondents (63% male),1,113 reported non-medical and 603 medical use of cannabis. Those reporting ≤monthly non-medical use before the pandemic had higher odds of increasing use during the pandemic than those using weekly before the pandemic (AOR 3.2 [95% CI 2.2-4.5]). Those reporting ≤ monthly and daily medical cannabis use before the pandemic had higher odds of increasing use during the pandemic than those using weekly before the pandemic (AOR 2.3 [95% 1.3, 3.9]; AOR 2.4 [95% CI 1.2, 5.1] respectively).Conclusions: The most notable increases in cannabis use during the pandemic were among those who reported using cannabis least frequently before the pandemic (two to three times odds of increased use among ≤ monthly use compared to weekly). These findings have important implications for potential health consequences related to increased cannabis use both during and after the pandemic, even in populations thought to be protected by minimal use prior to the pandemic

Drugs of Misuse: Focus on Vascular Dysfunction

Common drugs of misuse, including cannabis, opioids, stimulants, alcohol, and anabolic steroids, have strikingly disparate acute and chronic vascular effects, leading to a wide range of clinical cardiovascular presentations. Acute cannabis smoking has been associated with increased risk for myocardial infarction and ischemic stroke in otherwise healthy young people. However, it remains uncertain if people who exclusively smoke cannabis have increased risk for accelerated atherosclerosis similar to that found in people who exclusively smoke tobacco cigarettes. Cocaine and methamphetamines, both stimulants, increase risk for stroke, myocardial infarction, aortic dissection, and accelerated atherosclerosis, but only methamphetamine use is strongly linked to pulmonary hypertension. Chronic alcohol use is strongly associated with chronic hypertension and hemorrhagic stroke, but perhaps confers a lower risk for myocardial infarction. Finally, anabolic steroid use, presumably through adverse effects on circulating lipids and the hematopoietic system, is associated with increased risk for accelerated atherosclerosis and myocardial infarction. Physicians, especially cardiologists, emergency medicine, and internal medicine physicians, should be familiar with the short- and long-term vascular consequences of use of these substances, thereby ensuring appropriate, specific, and informed counselling and treatment

Changes in Secondary Substance Use After the Onset of the COVID-19 Pandemic Among People Who Use Cannabis: Findings From a Web-Based Sample of Adults in the United States

The coronavirus disease 2019 (COVID-19) pandemic has had widespread impacts on mental health and substance use. Increases in cannabis use have been documented in the United States, but little is known about how other substance use has changed among people who use cannabis. We sought to examine changes in alcohol, tobacco, opioid, and stimulant use during COVID-19 and explore how these changes relate to patterns of cannabis use. Data were obtained from a web-based survey of adults in the United States who use cannabis (n = 1,471) administered in September 2020. Using data reported in retrospective (prepandemic) and time-of-survey assessment periods, we explored changes in the prevalence of regular (≥ weekly) alcohol, tobacco, opioid, and stimulant use during COVID-19 among respondents who used medical and nonmedical cannabis. We used modified Poisson regression to examine cannabis-related correlates of increasing or decreasing secondary substance use during the pandemic. There was a slight but significant increase in ≥weekly alcohol use in the medical use group only (41.4%-47.0%, p = .034). ≥ Weekly tobacco, opioid, and stimulant use did not change significantly. Pandemic-concurrent shifts in secondary substance use depended on interacting cannabis-related factors including medical cannabis use, prepandemic cannabis frequency, and pandemic-concurrent frequency changes. For example, ≥ weekly prepandemic cannabis use was significantly and positively associated with decreasing opioid use frequency among the medical cannabis use group only. Assessments of the pandemic's effects on substance use should consider relationships between cannabis and other substances, which may differ according to cannabis-specific behaviors, motives, and contexts of use. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

Cannabis Use and Sharing Practices Among Sexual Minority and Heterosexual Individuals During the COVID-19 Pandemic

Purpose: Cannabis behaviors during the COVID-19 pandemic among sexual minority (SM) individuals in the United States remain understudied. This study assessed the prevalence and correlates of cannabis use and cannabis sharing, a potential risk for COVID-19 transmission, among SM and heterosexual-identified individuals in the United States during the COVID-19 pandemic. Methods: This cross-sectional study used data from an anonymous, US-based web survey on cannabis-related behaviors from August to September 2020. Included participants reported past-year nonmedical cannabis use. Associations between frequency of cannabis use and sharing behaviors by sexual orientation were evaluated using logistic regression analysis. Results: Overall, 1112 respondents reported past-year cannabis use; mean age 33 years (standard deviation = 9.4), 66% male identified (n = 723), and 31% SM identified adults (n = 340). Increased cannabis use during the pandemic was similar among SM (24.7%; n = 84) and heterosexual (24.9%; n = 187) respondents. Any sharing during the pandemic was 81% for SM adults (n = 237) and 73% for heterosexual adults (n = 486). In the fully adjusted models, the odds of daily/weekly cannabis use and the odds of any cannabis sharing among SM respondents were 0.56 (95% confidence interval [CI] = 0.42-0.74) and 1.60 (95% CI = 1.13-2.26), respectively, compared with heterosexual respondents. Conclusions: SM respondents were less likely to use cannabis with high frequency during the pandemic but more likely to share cannabis compared with heterosexual respondents. Sharing cannabis was high overall, which may increase COVID-19 risk. Public health messaging around sharing may be important during COVID-19 surges and respiratory pandemics especially as cannabis becomes more widely available in the United States

Selective Changes in Medical Cannabis Use Early in the COVID-19 Pandemic: Findings from a Web-Based Sample of Adults in the United States

Background: The COVID-19 pandemic has had widespread impacts on mental health and substance use. While increases in nonmedical cannabis use during COVID-19 have been documented among people who use cannabis across a diversity of settings, changes in specific medical applications of cannabis during the COVID-19 pandemic have not been characterized. We sought to examine changes in the prevalence, frequency, and mode of use of medical cannabis for a range of commonly treated conditions and symptoms during COVID-19. Methods: Data were obtained from an online survey of a sample of adults in the United States who use cannabis (n=1886), administered in September 2020. This study was restricted to participants who self-reported past-year medical cannabis use (n=598). Using data reported in a retrospective (pre-COVID) and current assessment period, we examined changes in cannabis use prevalence, frequency, and inhalation as the primary mode of administration for 11 commonly treated conditions. Results: There were slight but statistically significant increases in weekly (from 21.4% to 23.4%) and daily (from 16.2% to 20.7%) self-reported medical cannabis use during COVID-19 (p<0.001). Anxiety was the only specific therapeutic purpose for which daily cannabis use increased statistically significantly during COVID-19 (18.5% to 25.4%; p=0.004). In multivariable logistic regression, the odds of increasing cannabis use for anxiety during COVID-19 were statistically significantly higher for women, respondents from Western states, and states with legal medical and nonmedical cannabis. Discussion: We detected slight shifts toward higher frequencies of medical cannabis use during COVID-19. Disaggregated by therapeutic indication, daily cannabis use to manage anxiety increased during the pandemic. There is a need to assess whether changes in cannabis use that coincided with the pandemic will be sustained over time, and how these changes are connected to mental health outcomes, particularly among women