[excerpt] A new study identifying minor differences in the brain imaging of habitual marijuana consumers compared to non-users may be ideal for stimulating sensational headlines (e.g., “Regular pot smokers have shrunken brains, study says,” Los Angeles Times, November 10), but tells us little in regard to whether pot poses actual health risks.
Specifically, an MRI scan revealed less gray matter in the orbital frontal cortex of pot-smoking subjects compared to those who had never used the drug. Researchers also identified increased connectivity between certain regions of the brain in regular marijuana users compared with non-users.
So precisely what do these findings tell us in regard to pot use and health? Not much. Since the study design is not longitudinal, investigators cannot determine whether these differences are caused by subject’s cannabis use, whether these differences existed prior to subjects’ ever trying cannabis, or whether these differences persist when users’ cannabis consumption ceases.
Most importantly, investigators in this study failed to determine whether any of these differences are positively associated with any measurable adverse performance outcomes, such as cognitive performance or quality of life. It may be that these cannabis users are functioning in their daily lives in a manner that is indistinguishable from controls, in which case the imaging differences may hold little if any real-world significance. (In fact, one of the paper’s authors acknowledged, “[C]hronic users appear to be doing fine.”)
Full text of NORML’s response, “Media Leaping to Extremely Faulty Conclusions from Study on the Effects of Marijuana on the Brain,” appears online here.
Moderate cannabis consumption by young people is not positively associated with changes in intelligence quotient (IQ), according to data presented this week at the European College of Neuropsychopharmacology annual congress in Berlin, Germany.
Investigators at the University College of London analyzed data from 2,612 subjects who had their IQ tested at the age of eight and again at age 15. They reported no relationship between cannabis use and lower IQ at age 15 when confounding factors such as subjects’ history of alcohol use and cigarette use were taken into account.
“In particular alcohol use was found to be strongly associated with IQ decline,” the authors wrote in a press release cited by The Washington Post. “No other factors were found to be predictive of IQ change.”
Quoted in the Independent Business Times, the study’s lead author said: “Our findings suggest cannabis may not have a detrimental effect on cognition, once we account for other related factors particularly cigarette and alcohol use. This may suggest that previous research findings showing poorer cognitive performance in cannabis users may have resulted from the lifestyle, behavior and personal history typically associated with cannabis use, rather than cannabis use itself.”
The investigators acknowledged that more chronic marijuana use, defined in the study as a subject’s admission of having consumed cannabis 50 times or more by age 15, was correlated with slightly poorer exam results at the age of 16 — even after controlling for other variables. However, investigators admitted: “It’s hard to know what causes what. Do kids do badly at school because they are smoking weed, or do they smoke weed because they’re doing badly?”
Commenting on the newly presented data, the meeting’s Chair, Guy Goodwin, from the University of Oxford, told BBC News: “This is a potentially important study because it suggests that the current focus on the alleged harms of cannabis may be obscuring the fact that its use is often correlated with that of other even more freely available drugs and possibly lifestyle factors.”
In a recent review published in the New England Journal of Medicine, the NIDA Director Nora Volkow alleged that cannabis use, particularly by adolescents, is associated with brain alterations and lower IQ. However, the IQ study cited by Ms. Volkow as the basis of her claim was later questioned in a separate analysis published in the Proceedings of the National Academy of Sciences. That paper suggested that socioeconomics, not subjects’ cannabis use, was responsible for differences in IQ and that the plant’s “true effect [on intelligence quotient] could be zero.”
A previous assessment of cannabis use and its potential impact on intelligence quotient in a cohort of young people tracked since birth reported, “[M]arijuana does not have a long-term negative impact on global intelligence.”
Federal District Court Judge Asks: Should Federal Law Classify Cannabis As One Of The Nation’s Most Dangerous Drugs?October 20, 2014
Testimony regarding the constitutionality of the federal statute designating marijuana as a Schedule I Controlled Substance will be taken on Monday, October 27 in the United States District Court for the Eastern District of California in the case of United States v. Pickard, et. al., No. 2:11-CR-0449-KJM.
Members of Congress initially categorized cannabis as a Schedule I substance, the most restrictive classification available, in 1970. Under this categorization, the plant is defined as possessing “a high potential for abuse, … no currently accepted medical use in treatment in the United States, … [and lacking] accepted safety for … use … under medical supervision.”
Expert witnesses for the defense – including Drs. Carl Hart, Associate Professor of Psychology in the Department of Psychiatry and Psychology at Columbia University in New York City, retired physician Phillip Denny, and Greg Carter, Medical Director of St. Luke’s Rehabilitation Institute in Spokane, Washington – will testify that the accepted science is inconsistent with the notion that cannabis meets these Schedule I criteria.
“[I]t is my considered opinion that including marijuana in Schedule I of the Controlled Substances Act is counter to all the scientific evidence in a society that uses and values empirical evidence,” Dr. Hart declared. “After two decades of intense scientific inquiry in this area, it has become apparent the current scheduling of cannabis has no footing in the realities of science and neurobiology.”
The government intends to call Bertha Madras, Ph.D., Professor of Psychobiology at Harvard Medical School and the former Deputy Director for Demand Reduction for the White House Office of National Drug Control Policy under President George W. Bush.
Additional evidence has been presented by way of declarations by Marine Sgt. Ryan Begin, a veteran of the Iraq War; Jennie Stormes, the mother of a child suffering from Dravet Syndrome – a pediatric form of epilepsy that has been shown in preliminary trials to respond to specific compounds in the cannabis plant; James Nolan, Ph.D. an associate professor of sociology and anthropology at West Virginia University and a former crime analyst for the US Federal Bureau of Investigation; and Christopher Conrad, noted cannabis author, archivist, and cultivation expert.
This is the first time in recent memory that a federal judge has granted an evidentiary hearing on a motion challenging the statute which classifies cannabis to be one of the most dangerous illicit substances in the nation. Attorneys Zenia Gilg and Heather Burke, both members of the NORML Legal Committee, contend that the federal government’s present policies facilitating the regulated distribution of cannabis in states such as Colorado and Washington can not be reconciled with the insistence that the plant is deserving of its Schedule I status under federal law.
They write: “In effect, the action taken by the Department of Justice is either irrational, or more likely proves the assertions made in Part I (B) of this Brief: marijuana does not fit the criteria of a Schedule I Controlled Substance.”
Speaking recently in a taped interview with journalist Katie Couric, United States Attorney General Eric Holder expressed the need to revisit cannabis’ Schedule I placement under federal law. Holder said, “[T]he question of whether or not they should be in the same category is something that I think we need to ask ourselves, and use science as the basis for making that determination.”
The testimonial part of the evidentiary hearing in United States v. Pickard, et. al., is expected to last three days.
Israeli investigators intend to evaluate the potential anti-tumoral effects of the canabinoid cannabidiol (CBD) in select cancer patients.
Researchers at the Hassadah Medical Center in Jerusalem will conduct a Phase II clinical trial to assess the impact of CBD as single treatment in cancer patients who have failed to respond to conventional therapies. Participants in the trial will receive CBD therapy for a period of eight weeks.
Data documenting the potent anti-cancer activity of various cannabinoids – including THC, CBD, and CBG – both in culture and in animals dates back to the mid-1970s. To date, however, virtually no clinical trials exist reproducing these results in human subjects.
In August, pharmaceutical provider Insys Therapeutics announced that it had received orphan drug status for its proprietary formulation of CBD for the treatment of glioblastoma, a hard-to-treat, aggressive form of brain cancer.
Organic CBD remains classified under federal law as a schedule I controlled substance.
Further details of the forthcoming Israeli trial are available online from the clinicaltrials.gov website here. Patient recruitment has yet to begin for this study.
Traumatic brain injury (TBI) patients with a history of cannabis use possess increased survival rates compared to non-users, according data published this month in the scientific journal The American Surgeon.
UCLA Medical Center investigators conducted a three-year retrospective review of brain trauma patients. Data from 446 separate cases of similarly injured patients was assessed. Of those patients who tested positive for the presence of marijuana, 97.6 percent survived surgery. By contrast, patients who tested negative for the presence of pot prior to surgery possessed only an 88.5 percent survival rate.
“[O]ur data suggest an important link between the presence of a positive THC screen and improved survival after TBI,” the authors concluded. “This finding has support in previous literature because the neuroprotective effects of cannabinoids have been implicated in a variety of neurodegenerative diseases such as Alzheimer’s disease, Huntington’s disease, and multiple sclerosis. … With continued research, more information will be uncovered regarding the therapeutic potential of THC, and further therapeutic interventions may be established.”
The abstract of the study, “Effect of marijuana use on outcomes in traumatic brain injury,” appears online here.