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IACM-Bulletin of February 22, 2015
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Science/Human — Cannabis use may not have a significant effect on traffic accidents according to large US study
A new study from the US National Highway Traffic Safety Administration indicates cannabis use doesn't significantly increase traffic accident risk. The study looked at 9,000 drivers over the course of 20 months. It found drivers who regularly use cannabis are 25 percent more likely to be involved in a traffic accident. However, when the researchers factored in age, gender and level of alcohol consumption among cannabis users, they found that those factors were responsible for the increase. Cannabis use itself did not noticeably impact crash risk once the other factors were added.
"Analyses incorporating adjustments for age, gender, ethnicity, and alcohol concentration level did not show a significant increase in levels of crash risk associated with the presence of drugs," the study reads. "This finding indicates that these other variables (age, gender ethnicity and alcohol use) were highly correlated with drug use and account for much of the increased risk associated with the use of illegal drugs and with THC." The study indicates that drunk driving is still a major problem, but it also found drunk driving has decreased in recent years.
Press release by National Highway Traffic Safety Administration of 6 February 2015
Science/Human — How cannabis increases appetite
The uncontrollable urge to eat after using cannabis appears to be driven by neurons in the brain that are normally involved in suppressing appetite, according to a new study by Yale School of Medicine researchers in the journal Nature. Lead author Tamas Horvath and his colleagues set out to monitor the brain circuitry that promotes eating by selectively manipulating the cellular pathway that mediates the action of THC on the brain, using transgenic mice.
"By observing how the appetite center of the brain responds to marijuana, we were able to see what drives the hunger brought about by cannabis and how that same mechanism that normally turns off feeding becomes a driver of eating," said Horvath, director of the Yale Program in Cell Signaling and Neurobiology of Metabolism. "We were surprised to find that the neurons we thought were responsible for shutting down eating, were suddenly being activated and promoting hunger, even when you are full. It fools the brain's central feeding system," he said. A group of nerve cells called pro-opiomelanocortin (POMC) neurons are considered as key drivers of reducing eating when full. The activation of cannabinoid-1 receptors by THC promotes the activity of POMC cells.
Mulling the marijuana munchies: How the brain flips the hunger switch
Science/Human — Does cannabis very high in THC increase the risk of psychosis?
As a part of recent study into the psychological consequences of cannabis, a team of researchers in the United Kingdom looked at the details of first-episode psychotic incidents treated at hospitals in South London. "Compared with those who had never tried cannabis, users of high potency 'skunk-like' cannabis had a threefold increase in risk of psychosis," explained lead study author Dr Marta Di Forti, a professor at the Institute of Psychiatry, Psychology and Neuroscience at King's College London. "The risk to those who use every day was even higher; a fivefold increase compared to people who never use."
But critics of the study say that just because patients being treated for psychosis are more likely to have smoked cannabis on a regular basis, doesn't mean the drug caused their mental disorder. Di Forti and her colleagues acknowledge that they can't show the correlation to be causal. "Ecological studies such as this are pretty weak evidence for causation - if you just look at population level information like this, then you can't be sure that the people using cannabis are the same people developing psychosis," Suzi Gage, a University of Bristol researcher on the association between drugs and psychosis told The Washington Post.
News in brief
Germany — Bionorica applies for approval of THC medication
The German company Bionorica has applied for an approval of a capsulated dronabinol preparation to the German authorities. So far the medical conditions, for which it is intended to be used, are unclear. Bionorica is already extracting dronabinol (THC) from cannabis plants cultivated in Austria. Since 2002 pharmacies can prepare THC containing medications (capsules, solutions) from it.
Deutsche Apothekerzeitung of 18 February 2015
USA — More than 100 native american tribes consider growing cannabis
More than 100 Native American tribes have reached out to FoxBarry Farms, a management firm building the nation's first cannabis facility on tribal land, over the past month to express interest in the cannabis industry. There has been a surge of interest since the Department of Justice's announcement late last year that tribes are free to grow and sell cannabis on their lands as long as they adhere to specific guidelines.
Huffingtion Post of 3 February 2015
Science/Animal — The anti-psychotic effects of cannabidiol may in part be mediated by inhibition of microglial activation
Researchers used an animal model of schizophrenia to investigate the possible mechanism of action of CBD (cannabidiol) in the disease. They concluded that anti-psychotic effects of this cannabinoid may involve “anti-inflammatory and neuroprotective properties. Furthermore, our data support the view that inhibition of microglial activation may improve schizophrenia symptoms.” Microglia are immune cells in the brain.
Medical School of Ribeirão Preto, University of São Paulo, Brazil.
Gomes FV, et al. Schizophr Res. 2015 Feb 10. [in press]
Science/Animal — Mechanisms of action of anti-depressant effects of cannabinoids
A synthetic cannabinoid, which binds to the CB1 receptor caused anti-depressant-like effect in mice and this effect was mediated through interactions with the cholinergic system.
Medical University of Lublin, Poland.
Kruk-Slomka M, et al. Behav Brain Res. 2015 Feb 7. [in press]
Science/Animal — THC, but not other cannabinoids demonstrated effects on airway hyperresponsiveness and anti-inflammatory activity
Researchers compared the effects of THC, cannabidiol (CBD), cannabigerol (CBG), cannabichromene (CBC), cannabidiolic acid (CBDA) and tetrahydrocannabivarin (THCV) on contractions of the guinea-pig isolated trachea and bronchoconstriction. They concluded that only THC “demonstrated effects on airway hyperresponsiveness, anti-inflammatory activity and antitussive activity in the airways.”
King's College London, UK.
Makwana R, et al. J Pharmacol Exp Ther. 2015 Feb 5. [in press]
Science/Cells — Why CBD increases anandamide levels
Recent reports suggest that CBD and THC elevate the levels of the endocannabinoid anandamide (AEA) when administered to humans. New research shows that CBD does not inhibit the enzymatic actions of human FAAH (fatty acid amide hydrolase), the enzyme responsible for the degradation of anandamide “and thus FAAH inhibition cannot account for the observed increase in circulating AEA in humans following CBD consumption.” Instead scientists found that effects on fatty acid binding proteins (FABPs), intracellular proteins that mediate AEA transport to FAAH, were found to be responsible for increased endocannabinoid concentrations
Stony Brook University, New York, USA.