Co-use of cannabis and tobacco linked to poorer functioning among young adults

More than a third of young adults report using both cannabis and tobacco or nicotine products, providing a unique challenge to public health officials as cannabis is legalized in more jurisdictions, according to a new RAND Corporation study.

Studying a group of young adults from California, researchers examined the many different ways that cannabis and tobacco or nicotine products are used together—a byproduct of the introduction of new vaping devices and other delivery methods.

Among those surveyed, young adults who used cannabis and tobacco or nicotine together in some way (either using one right after the other or by mixing the products together) tended to consume more marijuana and tobacco or nicotine products, and report poorer functioning and more problematic behaviors compared to those who used did not use both products together. The study is published online by the journal Psychology of Addictive Behaviors.

Full story at Medical Xpress

Marijuana for morning sickness? It’s not great for baby’s brain

With a growing number of states legalizing recreational or medical marijuana, more women are using the drug during pregnancy, in part due to its reported ability to relieve morning sickness. A new study, conducted in rats, sheds light on how cannabis exposure affects the brain of a developing fetus.

Previous research has shown children born to mothers who used marijuana during pregnancy are more likely to develop behavioral problems as well as learning and memory impairments. The new research offers further confirmation on those findings and pinpoints how the drug alters the intricate connections in nerves in the hippocampus, the brain’s center for learning and memory. Understanding exactly how marijuana affects these brain connections could one day lead to interventions to reduce the damage, researchers say.

“The findings from this study will serve as an excellent premise for future interventions to restore memory in children exposed to cannabis during pregnancy, and for the first time, identify a specific mechanism by which learning and memory impairment occurs and how this impairment can be ameliorated,” said Priyanka Das Pinky, a graduate student in the laboratory of Vishnu Suppiramaniam, PhD, acting associate dean for research and graduate programs at Auburn University.

Full story at Science Daily

Severe psychological distress and daily cannabis use: Implications for mental health?

Daily cannabis use increased significantly from 2008 to 2016 among those with and without past-month serious psychological distress (SPD) and use among those with SPD was persistently higher compared to those without SPD. Research at Columbia Mailman School and CUNY shows that in 2016, past-month daily cannabis use was about three times higher for SPD (8%) compared to those without SPD (2.7%). The findings are online in the journal Drug and Alcohol Dependence.

“Our research found that persons with SPD reported higher daily cannabis prevalence each study year,” said senior author Renee Goodwin, PhD, Department of Epidemiology. “Therefore, it is important to consider potential consequences of this increased use for those with mental health vulnerabilities.”

Data were drawn from adults age 18 and older in the 2008-2016 National Survey on Drug Use and Health, a sample of 356,413 and measured by the Kessler Psychological Distress Scale.

Full story at Science Daily

Teen brain volume changes with small amount of cannabis use, study finds

At a time when several states are moving to legalize recreational use of marijuana, new research shows that concerns about the drug’s impact on teens may be warranted. The study, published in The Journal of Neuroscience, shows that even a small amount of cannabis use by teenagers is linked to differences in their brains.

Senior author and University of Vermont (UVM) Professor of Psychiatry Hugh Garavan, Ph.D., and first author and former UVM postdoctoral fellow Catherine Orr, Ph.D., say this research is the first to find evidence that an increase in gray matter volume in certain parts of the adolescent brain is a likely consequence of low-level marijuana use.

Few studies have looked at the effects of the first few uses of a drug, says Garavan. Most researchers focus on heavy marijuana users later in life and compare them against non-users. These new findings identify an important new area of focus.

Full story at Science Daily

Increased risk of harm from cannabis across Europe

Cannabis resin and herbal cannabis have significantly increased in potency and in price, according to the first study to investigate changes in cannabis across Europe.

The study, published today (Sunday 30 December) in the journal Addiction by researchers from the University of Bath and King’s College London, draws on data collected from across 28 EU Member states, as well as Norway and Turkey by the European Monitoring Centre for Drugs and Drug Addiction.

The findings show that for herbal cannabis, concentrations of delta-9-tetrahydrocannabinol (‘THC’ — the main psychoactive constituent of cannabis) increased by a similar amount each year, from 5% in 2006 to 10% in 2016.

Full story at Science Daily