Cannabis use and patient-reported outcomes among patients at a comprehensive cancer center.

BACKGROUND: Patients with cancer report increasing rates of cannabis use, often to manage symptoms and toxicities. The efficacy and safety of cannabis, however, for some use cases remains unclear. To better understand characteristics of patients with cancer who report using cannabis, we examined data from a cannabis use survey of among patients with cancer seen at a National Cancer Institute-Designated Cancer Center. METHODS: In late 2021, patients with cancer (N = 1608) treated between July 2017 and December 2019 provided cannabis use data. Additional data were obtained from medical records data and routine patient-reported outcomes collected for clinical purposes. Univariable analyses and multivariable regression analyses were conducted to identify correlates of cannabis use at different stages in the cancer care trajectory. RESULTS: Rates of self-reported cannabis use by patients with cancer were 59% before cancer diagnosis and 47% after diagnosis. Longitudinal rates of cannabis use were 29% for no cannabis use, 23% before diagnosis, 12% after diagnosis, and 35% for both before and after diagnosis. Demographic factors associated with cannabis use included age, sex, race, and educational achievement. Tobacco use and binge drinking were associated with higher odds of cannabis use. Cannabis use was also associated with greater self-reported interference with physical functioning due to pain and interference with social functioning due to health problems. CONCLUSIONS: We found high rates of cannabis use among patients with cancer, both before and after their cancer diagnosis. Future studies should further investigate psychosocial factors associated with cannabis use among patients with cancer as well as psychosocial outcomes among patients with cancer using cannabis.

Amygdala volume and depression symptoms in young adolescents who use cannabis.

INTRODUCTION: Both cannabis use and depressive symptomology increase in prevalence throughout adolescence. Concurrently, the brain is undergoing neurodevelopment in important limbic regions, such as the amygdala. Prior research indicates the amygdala may also be related to cannabis use and depressive symptoms. We aimed to investigate the effects of adolescent cannabis use on amygdala volumes as well as the interaction of cannabis use and amygdala morphometry on depressive symptoms in youth. METHOD: Two-hundred-twenty-four participants (ages 12-15), balanced by sex assigned at birth, were selected from a sub-sample of the Adolescent Brain Cognitive Development (ABCD) Study based on hair toxicology and self-report measures of cannabis use. Participants positive for cannabinoids in hair and/or self-reported cannabis use were demographically matched to youth with no self-reported or confirmed cannabis use. The guardians of these youth reported depression symptoms on the Child Behavioral Checklist. Linear mixed effect models were run investigating cannabis use group on amygdala volumes bilaterally, controlling for whole brain volume and random effects of scanner type. Additional analyses examined cannabis group status and bilateral amygdala volume on depression symptoms. RESULTS: Cannabis use was not significantly associated with amygdala volume but was associated with increased depressive symptoms (p<0.01). Cannabis group interacted with amygdala volume, such that individuals with smaller volumes had increased depressive symptoms within the cannabis group (p's<0.01-0.02). CONCLUSION: Aberrations in amygdala volume based on cannabis use were not found in early adolescence; however, more depressive symptoms were related to cannabis group. Youth who use cannabis and have smaller amygdala volumes were at increased risk for depressive symptomology, suggesting potential neurovulnerabilities to cannabis use.

The longitudinal assessment of prenatal cannabis use on neonatal outcomes.

OBJECTIVE: To investigate the association between prenatal cannabis use and perinatal outcomes using longitudinal data from pregnant individuals. STUDY DESIGN: This secondary-data analysis study utilized data collected from 894 pregnant individuals followed in the Stress in Pregnancy longitudinal study, conducted between 2009 and 2013. The status of cannabis use was ascertained through interviews and electronic medical record reviews to evaluate the effect of cannabis use on perinatal outcomes (NICU admission, preterm delivery, low birth weight, fetal death). RESULTS: Among participants analyzed, 13.1% used cannabis, who were generally younger (25.9 vs 27.9 years). There was a sevenfold increased risk of fetal death (OR 7.30) among cannabis users relative to non-users. Elevated risk persisted after adjustments of potential confounders (aOR 6.31). Adjusted models also suggested increased low birth weight risk (aOR 1.67). CONCLUSION: This study highlights an association between prenatal cannabis use and elevated risks for fetal death and low birth weight.

The Impact of Cannabis Use on Cognition in People with HIV: Evidence of Function-Dependent Effects and Mechanisms from Clinical and Preclinical Studies.

PURPOSE OF REVIEW: Cannabis may have beneficial anti-inflammatory effects in people with HIV (PWH); however, given this population's high burden of persisting neurocognitive impairment (NCI), clinicians are concerned they may be particularly vulnerable to the deleterious effects of cannabis on cognition. Here, we present a systematic scoping review of clinical and preclinical studies evaluating the effects of cannabinoid exposure on cognition in HIV. RECENT FINDINGS: Results revealed little evidence to support a harmful impact of cannabis use on cognition in HIV, with few eligible preclinical data existing. Furthermore, the beneficial/harmful effects of cannabis use observed on cognition were function-dependent and confounded by several factors (e.g., age, frequency of use). Results are discussed alongside potential mechanisms of cannabis effects on cognition in HIV (e.g., anti-inflammatory), and considerations are outlined for screening PWH that may benefit from cannabis interventions. We further highlight the value of accelerating research discoveries in this area by utilizing translatable cross-species tasks to facilitate comparisons across human and animal work.

The association between prenatal cannabis use and congenital birth defects in offspring: A cumulative meta-analysis.

OBJECTIVE: To examine the association between prenatal cannabis use and structural birth defects in exposed offspring. METHODS: In line with the preregistered protocol (PROSPERO: CRD42022368623), we systematically searched PubMed/Medline, CINHAL, EMBASE, Web of Science, ProQuest, Psych-Info, and Google Scholar for published articles until 25 January 2024. The methodological quality of the included studies was appraised by the Newcastle-Ottawa Quality Assessment Scale (NOS). A meta-analysis was carried out to report the pooled effect estimates from the included studies. We further performed subgroup, leave-one-out sensitivity, and meta-regression analyses, which increased the robustness of our findings. RESULTS: In this cumulative meta-analysis, thirty-six observational studies, consisting of 18 case-control and 18 cohort studies, with 230, 816 cases of birth defects and 18,049,013 controls (healthy babies) were included in the final analysis. We found that offspring exposed to maternal prenatal cannabis are at greater risks of a wide range of structural birth defects: cardiovascular/heart [OR = 2.35: 95 % CI 1.63 - 3.39], gastrointestinal [OR = 2.42: 95 % CI 1.61 - 3.64], central nervous system [OR = 2.87: 95 % CI 1.51 - 5.46], genitourinary [OR = 2.39: 95 % CI 1.11 - 5.17], and any (unclassified) birth defects [OR = 1.25: 95 % CI 1.12 - 1.41]. CONCLUSION: The findings from the current study suggest that maternal prenatal cannabis exposure is associated with a higher risk of different forms of structural birth defects in offspring. The findings underscore the significance of implementing preventive strategies, including enhanced preconception counselling, to address cannabis use during pregnancy and mitigate the risk of birth defects in offspring.

Understanding cannabis use and mental health difficulties in context with women's experiences of stressful events and social health issues in pregnancy: The Aboriginal Families Study.

BACKGROUND: Few population-based data sources fully recognise the intersections between stressful events, social health issues, and cannabis use in pregnancy, and little is known about sequelae for women's mental health. METHODS: We draw on two waves of population-based data for 344 families participating in the Aboriginal Families Study longitudinal cohort. We examine women's mental health in the first year postpartum and when children were aged 5-9 years in context with life experiences and use of cannabis in pregnancy. OUTCOMES: One in five women (19·5%) used cannabis during pregnancy (with or without co-use of tobacco). Within this group of women, 88·3% experienced 3 or more (3+) stressful events or social health issues. Psychological distress (Kessler-5 scale, K-5) in the year postpartum was substantially higher amongst women who had used cannabis or experienced 3+ stressful events or social health issues. High proportions of women met criteria for support and referral for depression and/or anxiety (52·5% of women who had used cannabis compared to 20·9% amongst women who had neither used cannabis nor tobacco; 43·2% of women who had experienced 3+ stressful events or social health issues compared to 15·6% amongst women who had not indicated these experiences). Similar patterns of psychological distress, depressive (9-item adapted Personal Health Questionnaire, aPHQ-9) and anxiety symptoms (7-item Generalised Anxiety Disorder score, GAD-7) were evident when the study children were aged 5-9 years. INTERPRETATION: Amongst women who had used cannabis in pregnancy, a high burden of psychological distress, depression, and anxiety is evident in the postpartum period and as their children turn 5-9 years. The overlay of stressful events and social health issues and the high proportion of women meeting criteria for referral for mental health assessment and support indicate an urgent need to offer women opportunities for safe disclosure of cannabis use and opportunities to access sustained holistic services. Reducing the harms of cannabis use on Aboriginal and Torres Strait Islander families must be coupled with culturally safe ways of addressing the social, historical, and structural determinants of mental health distress and harmful use of substances.

Impact of deceased organ donor marijuana use on donor culture positivity and solid organ transplant recipient outcomes.

With the increasing prevalence of marijuana use in the US, many deceased organ donors have a history of marijuana use, raising concerns about infectious risks to transplant recipients. We performed a multicenter retrospective cohort study in which exposed donors were those with recent marijuana use (in the prior 12 months) and unexposed donors were those with no recent marijuana use. Primary outcomes included the following: (1) positive donor cultures for bacteria or fungi, (2) recipient infection due to bacteria or fungi within 3 months posttransplant, and (3) recipient graft failure or death within 12 months posttransplant. Multivariable regression was used to evaluate the relationship between donor marijuana use and each outcome. A total of 658 recipients who received organs from 394 donors were included. Recent marijuana use was not associated with donor culture positivity (aOR: 0.84, 95% CI: 0.39-1.81, P = .65), recipient infection (aHR: 1.02, 95% CI: 0.76-1.38, P = .90), or recipient graft failure or death (aHR: 1.65, 95% CI: 0.90-3.02, P = .11). Our data suggest that organs from donors with a history of recent marijuana use do not pose significant infectious risks in the early posttransplant period.

Reduced Diffusivity along Perivascular Spaces on MR Imaging Associated with Younger Age of First Use and Cognitive Impairment in Recreational Marijuana Users.

BACKGROUND AND PURPOSE: The impairment of the glymphatic system, a perivascular network crucial for brain waste clearance, has been linked to cognitive impairment, potentially attributed to the accumulation of brain waste. Although marijuana use has been associated with poorer cognitive performance, particularly in adolescents, its influence on the glymphatic system remains unexplored. This study evaluated the influence of the age of first marijuana use and the total number of lifetime uses on the glymphatic system, measured using the index of DTI along the perivascular space (DTI-ALPS). Furthermore, we explored the correlation between glymphatic clearance and cognitive performance among marijuana users. MATERIALS AND METHODS: In this study, 125 individuals who reported using marijuana at least once in their lifetime (43 men; mean age, 28.60 [SD, 3.84] years) and 125 individuals with zero lifetime cannabis use (nonusers; 44 men; mean age, 28.82 [SD, 3.56] years) were assessed. ALPS indices of all study participants were calculated using 3T diffusion MR imaging data (b = 1000 s/mm2). RESULTS: After we adjusted for age, sex, education years, Pittsburgh Sleep Quality Index, alcohol use, tobacco use, and intracranial volume, our analysis using a univariate General Linear Model revealed no significant difference in the ALPS index among nonusers and marijuana users with different ages of first use or various frequencies of lifetime usage. However, in marijuana users, multiple linear regression analyses showed associations between a lower ALPS index and earlier age of first marijuana use (standardized ß, -0.20; P = .041), lower accuracy in the working memory 0-back task (standardized ß, 0.20; P = .042), and fewer correct responses in the Fluid Intelligence Test (standardized ß, 0.19; P = .045). CONCLUSIONS: This study shows the potential use of DTI-ALPS as a noninvasive indirect indicator of the glymphatic clearance in young adults. Our findings show novel adverse effects of younger age at first use of marijuana on the glymphatic system function, which is associated with impaired working memory and fluid intelligence. Gaining insight into the alterations in glymphatic function following marijuana use could initiate novel strategies to reduce the risk of cognitive impairment.

Recreational and Medical Cannabis Legalization and Opioid Prescriptions and Mortality.

Importance: While some have argued that cannabis legalization has helped to reduce opioid-related morbidity and mortality in the US, evidence has been mixed. Moreover, existing studies did not account for biases that could arise when policy effects vary over time or across states or when multiple policies are assessed at the same time, as in the case of recreational and medical cannabis legalization. Objective: To quantify changes in opioid prescriptions and opioid overdose deaths associated with recreational and medical cannabis legalization in the US. Design, Setting, and Participants: This quasiexperimental, generalized difference-in-differences analysis used annual state-level data between January 2006 and December 2020 to compare states that legalized recreational or medical cannabis vs those that did not. Intervention: Recreational and medical cannabis law implementation (proxied by recreational and medical cannabis dispensary openings) between 2006 and 2020 across US states. Main Outcomes and Measures: Opioid prescription rates per 100 persons and opioid overdose deaths per 100 000 population based on data from the US Centers for Disease Control and Prevention. Results: Between 2006 and 2020, 13 states legalized recreational cannabis and 23 states legalized medical cannabis. There was no statistically significant association of recreational or medical cannabis laws with opioid prescriptions or overall opioid overdose mortality across the 15-year study period, although the results also suggested a potential reduction in synthetic opioid deaths associated with recreational cannabis laws (4.9 fewer deaths per 100 000 population; 95% CI, -9.49 to -0.30; P = .04). Sensitivity analyses excluding state economic indicators, accounting for additional opioid laws and using alternative ways to code treatment dates yielded substantively similar results, suggesting the absence of statistically significant associations between cannabis laws and the outcomes of interest during the full study period. Conclusions and Relevance: The results of this study suggest that, after accounting for biases due to possible heterogeneous effects and simultaneous assessment of recreational and medical cannabis legalization, the implementation of recreational or medical cannabis laws was not associated with opioid prescriptions or opioid mortality, with the exception of a possible reduction in synthetic opioid deaths associated with recreational cannabis law implementation.

Adverse outcomes of cannabis use in Canada, before and after legalisation of non-medical cannabis: cross-sectional analysis of the International Cannabis Policy Study.

OBJECTIVES: To date, there is little evidence on the extent to which cannabis legalisation affects the prevalence of adverse events from cannabis at the population level. The current study examined trends in the prevalence of adverse events among people who consumed cannabis before and after Canada's legalisation of recreational cannabis. DESIGN: Data come from the first four survey waves of the International Cannabis Policy Study, which were conducted online annually immediately prior to non-medical cannabis legalisation in Canada in October 2018, and in the three following years (2019-2021). PARTICIPANTS: The current analysis included 18 285 Canadian respondents aged 16-65 who reported cannabis use in the past 12 months. OUTCOME MEASURES: Primary outcomes included types of adverse events experienced from cannabis use, medical help-seeking and the types of products used. Weighted logistic regression models examined differences in help-seeking, emergency room usage and the experience of cannabinoid hyperemesis syndrome across survey years. RESULTS: Approximately one-third of people who consume cannabis reported experiencing at least one adverse event within the past 12 months, including 5% of consumers who sought medical help for an adverse event, most commonly for panic attacks, feeling faint/dizzy/passing out, heart/blood pressure problems and nausea/vomiting. The prevalence of seeking help and the types of adverse events were similar before (2018) and after legalisation (2019-2021); however, the proportion of consumers seeking help from emergency rooms increased postlegalisation (F=2.77, p=0.041). Adverse events were associated with various product types, with dried flower and oral oils accounting for the largest proportion of events. Help-seeking associated with cannabis edibles significantly decreased after legalisation (p=0.001). CONCLUSIONS: Substantial proportions of people who consume cannabis report adverse events, suggesting widespread difficulty in 'dosing'. Few changes were observed in the prevalence of adverse events reported by consumers since legalisation; however, the location of medical help-seeking and associated products used have changed postlegalisation.

Perceptions and Attitudes Related to Driving after Cannabis Use in Canadian and US Adults.

BACKGROUND: This study examined the risk perceptions related to driving after cannabis use (DACU) among Canadian and US adults who used cannabis in the past six months. METHODS: Perceptions of danger, normative beliefs, perceived likelihood of negative consequences, and other driving-related variables were collected via online surveys in Canadian (n = 158; 50.0% female, 84.8% White, mean age = 32.73 years [SD = 10.61]) and US participants (n = 678; 50.9% female, 73.6% White, mean age = 33.85 years [SD = 10.12]). Driving cognitions and DACU quantity/frequency were compared between samples using univariate analyses of variance, and Spearman's (ρ) correlations were performed to examine associations between driving cognitions and DACU quantity/frequency. RESULTS: The two samples did not significantly differ in self-reported level of cannabis use, lifetime quantity of DACU, or the number of times they drove within two hours of cannabis use in the past three months (Ps > .12). Compared to US participants, Canadians perceived driving within two hours of cannabis use as more dangerous (P < 0.001, ηp2 = 0.013) and reported more of their friends would disapprove of DACU (P = 0.03, ηp2 = 0.006). There were no differences in the number of friends who would refuse to ride with a driver who had used cannabis (P = 0.15) or the perceived likelihood of negative consequences (Ps > 0.07). More favorable perceptions were significantly correlated with greater lifetime DACU and driving within two hours of use (ρ = 0.25-0.53, Ps < 0.01). CONCLUSIONS: These findings reveal differences in distal risk factors for DACU between Canada and the US and may inform prevention efforts focusing on perceptions of risk and social acceptance of DACU.

Prenatal cannabis use and the risk of attention deficit hyperactivity disorder and autism spectrum disorder in offspring: A systematic review and meta-analysis.

BACKGROUND: It is plausible that exposure to cannabis in-utero could be associated with an increased risk of neurodevelopmental disorders such as attention deficit hyperactivity disorder (ADHD) symptoms and autism spectrum disorder (ASD) during childhood and adolescence; however, mixed results have been reported. This study investigated whether there is an association between prenatal cannabis use and ADHD symptoms and ASD in offspring using a systematic review and meta-analysis methodology. METHODS: A systematic literature search was conducted in PubMed/Medline, Scopus, EMBASE, Web of Science, Psych-Info, and Google Scholar to identify relevant studies. The study protocol has been preregistered in the Prospective Register of Systematic Reviews (PROSPERO) (CRD42022345001), and the Newcastle-Ottawa Quality Assessment Scale (NOS) was used to assess the methodological quality of included studies. An inverse variance weighted random effect meta-analysis was conducted to pool the overall effect estimates from the included studies. RESULTS: Fourteen primary studies, consisting of ten on ADHD and four on ASD, with a total of 203,783 participants, were included in this study. Our meta-analysis underscores an increased risk of ADHD symptoms and/or disorder [ß = 0.39: 95 % CI (0.20-0.58), I2 = 66.85 %, P = 0.001)] and ASD [RR = 1.30: 95 % CI (1.03-1.64), I2 = 45.5 %, P = 0.14] associated with in-utero cannabis exposure in offspring compared to their non-exposed counterparts. Additionally, our stratified analysis highlighted an elevated risk of ADHD symptoms [ß = 0.54: 95 % CI (0.26-0.82)] and a marginally significant increase in the risk of diagnostic ADHD among exposed offspring compared to non-exposed counterparts [RR = 1.13, 95 % CI (1.01, 1.26)]. CONCLUSION: This study indicated that maternal prenatal cannabis exposure is associated with a higher risk of ADHD symptoms and ASD in offspring.

The Puzzle of Marijuana Use and Forced Vital Capacity.

In study after study, marijuana use has been found to be associated with increased forced vital capacity (FVC). This is puzzling, because marijuana is commonly consumed by inhalation of its smoke, and smoke exposure of any kind is not generally considered a cause of increased FVC. Although this observation was first made decades ago, a satisfactory explanation remains elusive. In this review we survey the evidence supporting the relationship between marijuana use and increased FVC, discuss potential threats to validity when inferring causation, and, presupposing a possible causal relationship, pose two key questions. First, what are possible physiologic or pathophysiologic mechanisms by which marijuana use might increase FVC? Second, why might this effect be consistently observed with marijuana use but not with tobacco use? Explanations for the first question include lung and chest growth and remodeling from strenuous marijuana smoke inhalation and reductions in lung elastic recoil from marijuana smoke exposure. Explanations for the second include differences between marijuana and tobacco in smoke composition and patterns of consumption, such as smoking topography. Finally, the possibility that smoke, whether from marijuana or tobacco, might have nonmonotonic effects on FVC depending on the degree of exposure is explored. In synthesizing a curated breadth of epidemiologic and physiologic science, we leverage a perplexing observation to generate potential insights and avenues for further research into the biological effects of smoke, from marijuana or otherwise, on the respiratory system.