NORML reviews the top news stories of 2015.
#1 Congress Reauthorizes Medical Marijuana Protections
Members of Congress approved language in the fiscal year 2016 omnibus spending bill that continues to limit the federal government from taking punitive action against state-licensed individuals or operations that are acting are in full compliance with the medical marijuana laws of their states. The provisions reauthorize Section 538 of the Continuing Appropriations Act of 2015, which states, "None of the funds made available in this act to the Department of Justice may be used … to prevent … states … from implementing their own state laws that authorize the use, distribution, possession, or cultivation of medical marijuana."
#2 Federal Judge Upholds Marijuana’s Schedule I Status
A federal judge in April rejected a motion challenging the constitutionality of cannabis’ classification as a Schedule I prohibited substance. "At some point in time, a court may decide this status to be unconstitutional," Judge Kimberly Mueller said from the bench. "But this is not the court and not the time." Judge Meuller had presided over five days of hearings in October 2014 in a challenge brought by members of the NORML Legal Committee.
#3 Medical Cannabis Access Associated With Less Opioid Abuse
States that permit qualified patients to access medical marijuana via dispensaries possess lower rates of opioid addiction and overdose deaths, according to a study published in July by the National Bureau of Economic Research, a non-partisan think-tank. The findings mirror those published in 2014 in The Journal of the American Medical Association concluding, "States with medical cannabis laws had a 24.8 percent lower mean annual opioid overdose mortality rate compared with states without medical cannabis laws."
#4 DC Depenalizes Marijuana; Arrests Plummet
Despite threats from members of Congress, District officials implemented voter-approved legislation earlier this year eliminating penalties associated with the possession and cultivation of personal use quantities of marijuana by adults. Following the law’s implementation, marijuana-related arrests in the nation’s capital fell 99 percent.
#5 Marijuana Law Changes Don’t Change Youth Use, Attitudes
Rates of youth marijuana use are unaffected by changing laws, according to data published in July in The American Journal of drug and Alcohol Abuse. Investigators evaluated trends in young people’s attitudes toward cannabis and their use of the substance during the years 2002 to 2013 – a time period where 14 states enacted laws legalizing the medical use of the plant, and two states approved its recreational use by adults. "Our results may suggest that recent changes in public policy, including the decriminalization, medicalization, and legalization of marijuana in cities and states across the country, have not resulted in more use or greater approval of marijuana use among younger adolescents," researchers reported.
#6 Gallup Poll: More Americans Than Ever Say Marijuana Should Be Legal
Fifty-eight percent of Americans believe that "the use of marijuana should be made legal," according to nationwide survey data released in October by Gallup pollsters. The percentage ties the highest level of support ever reported by Gallup, which has been measuring Americans’ attitudes toward cannabis since the late 1960s. The percentage is more than twice the level of support reported in the mid-1990s.
#7 Study: Marijuana Use Not Associated With Changes In Brain Morphology
Marijuana use is not associated with structural changes in the brain, according to imaging data published in January in The Journal of Neuroscience. Investigators assessed brain morphology in both daily adult and adolescent cannabis users compared to non-users. They found "no statistically significant differences … between daily users and nonusers on volume or shape in the regions of interest" after researchers controlled for participants’ use of alcohol. "[T]he results indicate that, when carefully controlling for alcohol use, gender, age, and other variables, there is no association between marijuana use and standard volumetric or shape measurements of subcortical structures," researchers reported.
#8 Marijuana Consumers Less Likely To Be Obese, Suffer Diabetes Risk
Those who consume cannabis are 50 percent less likely to suffer from metabolic syndrome as compared to those who do not, according to findings published in November in The American Journal of Medicine. Metabolic syndrome is a group of risk factors, including high blood pressure, high blood sugar, unhealthy cholesterol levels, and abdominal fat, which are linked to increased risk of heart disease and adult onset diabetes, among other serious health consequences. The findings are similar to those of previous studies reporting that those who use cannabis are less likely to be obese or suffer from diabetes.
#9 NHTSA: THC-Positive Drivers Don’t Possesses Elevated Crash Risk
Drivers who test positive for the presence of THC in their blood are no more likely to be involved in motor vehicle crashes than are drug-free drivers, according to a case-control study released in February by the United States National Highway Transportation and Safety Administration. Authors reported that drivers who tested positive for the presence of THC possessed an unadjusted, elevated risk of accident of 25 percent (Odds Ratio=1.25) compared to controls (drivers who tested negative for any drug or alcohol). However, this elevated risk became insignificant (OR=1.05) after investigators adjusted for demographic variables, such as the drivers’ age and gender. The study is the largest of its kind ever conducted in the United States.
#10 Legal Marijuana States Collect Over $200 Million In New Tax Revenue
Taxes on the legal production and sale of cannabis in the states of Colorado and Washington have yielded over $200 million in new revenue since going into effect in 2014, according to calculations reported by The Huffington Post in September. Colorado collected more than $117 million dollars from marijuana sales while Washington collected over $83 million. Cannabis sales commenced in Oregon in on October 1, 2015 and have yet to begin in Alaska.
Two new studies published online today in JAMA (Journal of the American Medical Association) Psychiatry provide little support for previous claims that cannabis exposure is significantly harmful to the developing brain.
The first study, which assessed the effects of cannabis exposure on brain volume in exposed and unexposed sibling pairs, reported that any identifiable differences “were attributable to common predispositional factors, genetic or environmental in origin.” By contrast, authors found “no evidence for the causal influence of cannabis exposure” on brain morphology.
The trial is “the largest study to date examining the association between cannabis exposure (ever versus never used) and brain volumes.”
The study is one of two recent clinical trials to be published in recent months rebutting the claims of a widely publicized 2014 paper which alleged that even casual marijuana exposure may be linked to brain abnormalities, particularly in the region of the brain known as the amygdala. In January, researchers writing in The Journal of Neuroscience reported “no statistically significant differences … between daily [marijuana] users and nonusers on [brain] volume or shape in the regions of interest” after researchers controlled for participants’ use of alcohol. Similarly, today’s JAMA study “casts considerable doubt on hypotheses that cannabis use … causes reductions in amygdala volumes.”
A second study appearing today in the journal assessed whether cannabis use during adolescence is associated with brain changes that may be linked to an increased risk of schizophrenia. While researchers reported finding an association among male subjects who possessed a high genetic predisposition toward schizophrenia, authors reported that no such association existed among male subjects who were at low risk for the disease, or among females in either the high risk or low risk categories. The finding is consistent with the theory that early onset cannabis use may potentially exacerbate symptoms in a minority of subjects predisposed to the disease, but it contradicts claims that marijuana exposure is a likely cause of schizophrenia, particularly among those who are not already vulnerable to the disease.
Abstracts of both new studies appear online in JAMA Psychiatry here and here.
It was less than a year ago when the mainstream media was chock-full of headlines like this one: ‘Brain changes associated with casual marijuana use in young adults, study finds.’ The alarmist headlines were in response to a controversial paper published by researchers at Harvard University in Boston and Northwestern University in Chicago which alleged to have found differences in brain morphology in a cohort of 20 college-age marijuana users as compared to 20 non-users. The study’s investigators attributed the differences to subjects’ cannabis use.
But a funny thing happened when a team of scientists from the University of Colorado and the University of Kentucky tried to replicate these results in a separate, larger sample (158 participants) of subjects after rigorously controlling for both groups’ use of alcohol.
Writing in the January 28 edition of The Journal of Neuroscience, authors summarized:
“[T]his retrospective study examined brain morphology in a sample of adult daily marijuana users (n = 29) versus nonusers (n = 29) and a sample of adolescent daily users (n = 50) versus nonusers (n = 50). Groups were matched on a critical confounding variable, alcohol use, to a far greater degree than in previously published studies.
We acquired high-resolution MRI scans, and investigated group differences in gray matter using voxel-based morphometry, surface-based morphometry, and shape analysis in structures suggested to be associated with marijuana use, as follows: the nucleus accumbens, amygdala, hippocampus, and cerebellum.
No statistically significant differences were found between daily users and nonusers on volume or shape in the regions of interest. Effect sizes suggest that the failure to find differences was not due to a lack of statistical power, but rather was due to the lack of even a modest effect.”
Why the contradictory results? Investigators speculated that previously reported imaging studies failed to adequately control for the impact of alcohol, a substance that “unlike marijuana, … has been unequivocally associated with deleterious effects on brain morphology and cognition in both adults and adolescents.” In other words, researchers theorized that previously reported differences in the brain images of marijuana consumers as compared to non-users were likely because of subjects consumption of booze, not cannabis.
They concluded, “In sum, the results indicate that, when carefully controlling for alcohol use, gender, age, and other variables, there is no association between marijuana use and standard volumetric or shape measurements of subcortical structures. … [I]t seems unlikely that marijuana use has the same level of long-term deleterious effects on brain morphology as other drugs like alcohol. The press may not cite studies that do not find sensational effects, but these studies are still extremely important.”
An abstract of the study, “Daily Marijuana Use Is Not Associated with Brain Morphometric Measures in Adolescents or Adults,” is online here.
[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.”