#NORML #News Source: @norml @WeedConnection Posted By: norml@weedconnection.com media :: news - Wed, 09 Aug 2017 04:20:21 PST
Study: Adolescent Cannabis Use Not Independently Linked With IQ Decline
Tempe, AZ: The habitual use of cannabis by teens is not independently linked with adverse changes in intelligence quotient or executive functioning, according to longitudinal data published online ahead of print in the journal Addiction.
A team of investigators from the United States and the United Kingdom evaluated whether marijuana use is directly associated with changes over time in neuropsychological performance in a nationally representative cohort of adolescent twins. Authors reported that "family background factors," but not the use of cannabis negatively impacted adolescents' cognitive performance.
They wrote: "[W]e found that youth who used cannabis ... had lower IQ at age 18, but there was little evidence that cannabis use was associated with IQ decline from age 12 to 18. Moreover, although cannabis use was associated with lower IQ and poorer executive functions at age 18, these associations were generally not apparent within pairs of twins from the same family, suggesting that family background factors explain why adolescents who use cannabis perform worse on IQ and executive function tests."
Investigators concluded, "Short-term cannabis use in adolescence does not appear to cause IQ decline or impair executive functions, even when cannabis use reaches the level of dependence."
Their findings are consistent with those of several other studies - including those here, here, here, and here - finding that cannabis use alone during adolescence does not appear to have a significant, direct adverse effect on intelligence quotient.
A widely publicized New Zealand study published in 2012 in The Proceedings of the National Academy of Sciences reported that the persistent use of cannabis from adolescence to adulthood was associated with slightly lower IQ by age 38. However, a follow up review of the data published later in the same journal suggested that the observed changes were likely due to socioeconomic differences, not the subjects' use of cannabis.
Full text of the study, "Associations between adolescent cannabis use and neuropsychological decline: A longitudinal co-twin control study," appears in Addiction.
Study: Cannabis Smoking Not Associated With Changes In The Hippocampus
Amsterdam, The Netherlands: The regular use of cannabis by young people is not associated with hippocampal volume alterations, according to case-control longitudinal data published online ahead of print in the Journal of Psychopharmacology.
Investigators from the Netherlands and the United Kingdom conducted magnetic resonance imaging (MRI) scans at baseline and at follow up (average of 39-months post-baseline) in 20 habitual cannabis users and in 23 non-using controls.
Authors reported: "Compared to controls, cannabis users did not show hippocampal volume alterations at either baseline or follow-up. Hippocampal volumes increased over time in both cannabis users and controls, following similar trajectories of increase. Cannabis dose and age of onset of cannabis use did not affect hippocampal volumes."
They concluded, "Continued heavy cannabis use did not affect hippocampal neuroanatomical changes in early adulthood. ... These data suggest that cannabis users show the same developmental trends as normative samples and that heavy cannabis use in this group may not necessarily interfere with hippocampal changes in neuroanatomy in early adulthood."
The findings are consistent with other recent studies, such as those here and here, finding that the use of alcohol but not cannabis is negatively associated with specific structural changes in the developing brain.
Full text of the study, "Longitudinal study of hippocampal volumes in heavy cannabis users," appears in The Journal of Psychopharmacology.
Case Report: CBD Administration Associated With ALS Modulation
Wien, Austria: The co-administration of cannabidiol (CBD) with the prescription drug riluzole (marketed as Rilutek) is associated with the delayed onset of amyotrophic lateral sclerosis (ALS aka Lou Gehrig's disease), according to a case report published in the Journal of General Practice.
A researcher reported that the administration of 300mg of CBD twice daily was associated with the limited progression of various ALS symptoms in a single patient.
The author wrote, "It is concluded, that co-medication with CBD may be able to slow down the progression of some but not all symptoms of motor neuron disease."
Preclinical data indicates that cannabinoids possess neuroprotective properties that may hold promise in the treatment of brain diseases like ALS. However, clinical trials assessing the efficacy of cannabis treatment in ALS patients have yet to be conducted.
Full text of the study, "Co-medication with cannabidiol may slow down the progression of motor neuron disease: A case report," appears in the Journal of General Practice.
Colorado: Tax Revenues From The Legal Cannabis Industry Surpasses Half-Billion Dollars
Denver, CO: Revenues from Colorado's legal cannabis industry have surpassed over a half-billion dollars since retail sales began on January 1, 2014.
According to an analysis by VS Strategies, cannabis-specific taxes and fees have yielded $506,143,635 in state revenue over the past three and one-half years. (Local tax revenue was excluded from the analysis.) Much of the revenue raised has gone to fund school construction projects, school drop-out and substance abuse prevention programs, and grant funding.
The half-billion dollar total far exceeds initial projections. Tax revenue from legal cannabis sales in Oregon and Washington have also exceeded regulator's initial expectations, In Nevada, where retail sales became legal on July 1, retailers reported over 40,000 transactions in just the first weekend. In Alaska, legal cannabis sales have generated $1.2 million dollars in tax revenue over the first eight months.
