Cannabis and driving: A new perspective

Cannabis and driving is an emerging injury‐prevention concern. The incidence of driving while affected by cannabis is rising in parallel with increased cannabis use in the community. Younger drivers are at particular risk. Improvements in research methodology, technology and laboratory testing methods have occurred in the last 10 years. These cast doubt on earlier results and conclusions. Studies now show that cannabis has a significant impairing effect on driving when used alone and that this effect is exaggerated when combined with alcohol. Of particular concern is the presence of cannabis as the sole psychoactive drug in an increasing number of road fatalities and the lack of any structural response to this problem. A review of testing methods, laboratory and real driving studies, and recent epidemiological studies is presented. Suggestions for methods of further data collection and future public policy are made.     

The consistency of peer and parent influences on tobacco,alcohol, and marijuana use among young adolescents

The purpose of this study was to determine the degree to which the use of tobacco, alcohol, and marijuana by young adolescents can be described using a common theoretical model. Structural models were created in which psychosocial variables hierarchically predicted the use of each substance. The fit of a model in which paths from predictor variables were constrained to be equal was not inferior in any meaningful way to that of a model in which all path coefficients were freely estimated, thus suggesting that use of tobacco, alcohol, and marijuana by young adolescents may be considered to be a unitary phenomenon. A simplified model, in which these substances were combined into a single latent variable, showed a good fit. The results of these analyses suggest that it may be beneficial to consider adolescent substance use to be a unitary phenomenon.This research was supported by National Institute on Drug Abuse Grant 1-R18-DA-003406.     

The associations of medical marijuana policies with opioid‐related health care utilization

ObjectiveTo examine the associations between medical marijuana policies and opioid‐related hospitalizations and emergency department visits.Data SourcesWe utilized quarterly rates of hospital discharge data from the Healthcare Cost and Utilization Project''s (HCUP) Fast Stats Database from 2005 to 2016 along with state‐level sociodemographic data from US Census Bureau and Bureau of Labor Statistics and opioid‐related state health policy data from publicly available sources for the analysis.Study DesignAnalyses were carried out using a difference‐in‐differences regression approach. We estimate heterogeneous effects of medical marijuana policies such as initial policy, presence of active dispensary, and home cultivation on opioid‐related hospitalizations and emergency department visits related to opioids.Data Collection/Extraction MethodsPublicly available secondary data were collected, linked, and analyzed. Observations with missing values for explanatory variables were excluded from the analysis.Principal FindingsRegression results indicate that type of medical marijuana policy has varying effects on opioid‐related hospitalizations and emergency department visits. States that allow home cultivation of medical marijuana experienced significant positive associations with opioid‐related hospitalizations and emergency department visits, while no effect was observed with medical marijuana dispensaries. Moreover, recreational marijuana policies were positively associated with opioid‐related hospitalizations.ConclusionsThe findings indicate that the effects of medical marijuana policies on opioid‐related hospitalizations and emergency department visits vary depending on the type of medical marijuana policy. Our findings indicate that the implementation of home cultivation of marijuana is positively associated with hospitalizations and emergency department visits related to opioids, suggesting that easier access to marijuana among opioid users may result in adverse health conditions that need treatment.     

Implications of the 2018 Canadian Cannabis Act: Should regulation differ for medicinal and non-medicinal cannabis use?⋆

The regulatory framework for access to medical cannabis has been established in Canada since 2001, with the number of patients seeking access growing substantially over the years. With the novel enactment of the Cannabis Act in October 2018, Canada now maintains two distinct mechanisms for accessing cannabis - one for medical cannabis and the other for non-medical cannabis. With two regulatory access mechanisms in place, questions have arisen in the country as to the necessity of maintaining regulatory separation and the integrity of the medical access framework. A single framework would remove the gate-keeping function that the medical profession currently holds, streamlining processes and simplifying the current regulatory landscape. This approach has been advocated for by the Canadian Medical Association, despite objections from multiple stakeholders. Critical questions arise should the medical access framework be dissolved into a single, non medical-based regulatory framework. Insurance coverage, control mechanisms, market incentives, and patient obligations represent some examples of these issues. This paper will expand upon these considerations and highlight why maintaining two separate access mechanismss best serves the Canadian public. As medicinal cannabis continues to be liberated in international jurisdictions, this paper can help to illuminate the current status of medical cannabis in Canada, and provide insights to those from other countries on our current approach and domestic challenges.     

The human toxicity of marijuana: a critique of a review by Nahas and Latour

A review entitled “The human toxicity of marijuana” was published in 1992 in the Medical Journal of Australia. The authors claimed that the adverse effects of cannabis use have been trivialized and that the effects are much more serious than earlier reported. We have made a careful study of this review and examined the claims made. We compared the claims of the authors with the information contained in the documents they cited and found that at least 28 of the 35 citations in this article were cited inaccurately. Five of these publications were misquoted, or the findings of the study were not fully reported. Twenty-three citations contained other errors, leaving only six to eight (two citations could not be retrieved because of their obscurity) accurate citations among 35. All of these inaccuracies operate in the direction of finding an adverse effect of marijuana.     

Combinedin vitro effect of marijuana and retrovirus on the activity of mouse natural killer cells

Both marijuana and retroviruses impair natural killer (NK) cell functions, but no data on their simulataneous effects are available. Similarities to human AIDS induced by Friend leukemia complex (FLO and its helper Rowson-Parr virus (RPV) provides a mouse model to study drug-virus action. Leukemia susceptible BALB/c and resistant C57BL/6 mice were infected, then at time intervals their nylon wool-separated splenocytes were exposed to tetrahydrocannabinol (THC) for 3h. Natural killer cell activity against Yac-1 cells was assayed by 51Cr-release for 4 and 18h. Recovery of splenocytes was found to be suppressed by FLC, but in BALB/c only by RPV. After a transient enhancement in C57BL/6 by FLC, NK cell activity of both mice became suppressed early (2 to 4 days), normalized subsequently and enhanced late (11 to 14 days) postinfection. A moderate increase in BALB/c, no change in C57BL/6 were induced by low (1-2.5 g/ml) THC doses. NK cell activity of BALB/c became suppressed exponentially by higher (5-10 g/ ml) THC doses in 18h as compared to 4h assays, while its proportional and moderate impairment was seen in C57BL/6. The magnitude of NK cell activity of infected mice was determined by THC: enhancement or impairment followed those of untreated, infected counterparts on the level of THC-treated cells. Low doses hardly, high doses additively influenced NK cells of infected BALB/c. THC slightly affected very early and late enhancement in NK cell activity of FLC infected C57BL/6, but augmented RPV induced suppression late in 18h assays. Genetic factors similar to endotoxin resistance, altered cytokine profile might determine these effects. Similar phenomena in humans might result in earlier manifestation of AIDS.     

贵州省织金县吸毒人群HIV感染者感染状态暴露情况调查

目的 描述贵州省织金县人类免疫缺陷病毒(human immunodeficiency virus，HIV)阳性吸毒者将自己感染状态暴露给其他人的比例和原因。方法 通过深入访谈的方式搜集40名来自社区和戒毒所知晓自己HIV阳性的吸毒者的定量和定性资料。结果 85％(34／40)的研究对象将自己的感染状态暴露给家庭成员，其中24人(60％)为自愿暴露，10人(25％)为未经同意的暴露，暴露的主要原因是希望得到家人情感上和物质上的支持。在获知自己感染HIV后，16人有吸毒的固定性伴，均把自己的感染状态暴露给了这些固定性伴；另外4人有不吸毒固定性伴，其中2人未将感染状态暴露给这些固定性伴。75％(30／40)的研究对象把自己感染HIV的状态暴露给吸毒的朋友，暴露的主要原因是“劳教所不接收HIV感染者，害怕被劳教”、“吸毒者中感染的人也很普遍”。而仅有12．5％(5／40)的研究对象将感染状态暴露给其他亲戚或不吸毒的朋友。结论 大多数HIV感染的吸毒者愿意把自己的感染状态暴露给家庭成员和吸毒的朋友或固定性伴，这有利于HIV感染者得到来自家庭的关怀和医疗照顾，也有利于HIV阴性吸毒者了解吸毒同伴的感染状态。     

Lung bullae and pulmonary fibrosis associated with marijuana smoking

A 26‐year‐old man with a history of heavy marijuana and minimal tobacco use was found to have extensive bilateral lung bullae and interstitial fibrosis, heavily infiltrated by pigmented macrophages. These features can be associated with marijuana smoking. The differential diagnoses in this patient are also discussed.