Per se driving limits for the presence of THC are arbitrary and may improperly classify motorists who are not behaviorally impaired, according to the findings of a study published today by the American Automobile Association (AAA) Foundation for Traffic Safety.
Per se driving limits criminalize the act of operating a motor vehicle if the driver possesses detectable amounts of specific drugs or drug metabolites above a set threshold. Under these laws, drivers are guilty per se of violating the traffic safety laws even absent evidence of demonstrable behavioral impairment.
Five states – Montana, Nevada, Ohio, Pennsylvania, and Washington – presently impose per se limits for the detection of specific amounts of THC in blood while eleven states (Arizona, Delaware, Georgia, Illinois, Indiana, Iowa, Michigan, Oklahoma, Rhode Island, Utah, and Wisconsin) impose zero tolerant per se standards. In Colorado, the presence of THC in blood above 5ng/ml “gives rise to permissible inference that the defendant was under the influence.” Legislation similar to Colorado’s law is presently pending in California.
However, the AAA report concludes, “[A] quantitative threshold for per se laws for THC following cannabis use cannot be scientifically reported.” This is because the body metabolizes THC in a manner that is significantly distinct from alcohol. In particular, acute effects of cannabinoids lag well behind the presence of maximum THC/blood levels. Additionally, residual levels of THC may be present in blood for extended periods of time, long after any psychomotor-related effects have ceased.
The Automobile Association’s finding is similar to that of the US National Highway Traffic Safety Administration, which acknowledges: “It is difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects. … It is inadvisable to try and predict effects based on blood THC concentrations alone.”
NORML has long articulated a similar opposition to the imposition of per se driving thresholds for THC and/or its metabolites, stating, “[R]ecently adopted statewide per se limits and zero tolerant per se thresholds in the United States criminally prohibiting the operation of a motor vehicle by persons with the trace presence of cannabinoids or cannabinoid metabolites in their blood or urine are not based upon scientific evidence or consensus. … [T]he enforcement of these strict liability standards risks inappropriately convicting unimpaired subjects of traffic safety violations, including those persons who are consuming cannabis legally in accordance with other state statutes.”
Rates of prescription opioid abuse are significantly lower in jurisdictions that permit medical marijuana access, according to data reported by Castlight Health, an employee health benefits platform provider.
Investigators assessed anonymous prescription reporting data from over one million employees between the years 2011 and 2015.
In states that did not permit medical marijuana access, 5.4 percent of individuals with an opioid prescription qualified as abusers of the drug. (The study’s authors defined “abuse” as opioid use by an individual who was not receiving palliative care, who received greater than a 90-day cumulative supply of opioids, and received an opioid prescription from four or more providers.) By contrast, only 2.8 percent of individuals with an opioid prescription living in medical marijuana states met the criteria.
The findings are similar to those reported by the RAND Corporation in 2015, which determined, “[S]tates permitting medical marijuana dispensaries experience a relative decrease in both opioid addictions and opioid overdose deaths compared to states that do not.”
Data published in 2014 in the Journal of the American Medical Association (JAMA) Internal Medicine also reported that the enactment of statewide medicinal marijuana laws is associated with significantly lower state-level opioid overdose mortality rates, finding, “States with medical cannabis laws had a 24.8 percent lower mean annual opioid overdose mortality rate compared with states without medical cannabis laws.”
Full text of the new study, “The opioid crisis in America’s workforce,” appears online here.
Chronic pain patients with legal access to medicinal cannabis significantly decrease their use of opioids, according to data published online ahead of print in The Journal of Pain.
Investigators at the University of Michigan, Ann Arbor conducted a retrospective survey of 244 chronic pain patients. All of the subjects in the survey were qualified under Michigan law to consume medicinal cannabis and frequented an area dispensary to obtain it.
Authors reported that respondents often substituted cannabis for opiates and that many rated marijuana to be more effective.
“Among study participants, medical cannabis use was associated with a 64% decrease in opioid use, decreased number and side effects of medications, and an improved quality of life,” they concluded. “This study suggests that many chronic pain patients are essentially substituting medical cannabis for opioids and other medications for chronic pain treatment, and finding the benefit and side effect profile of cannabis to be greater than these other classes of medications.”
About 40 people die daily from opioid overdoses, according to the US Centers for Disease Control.
Clinical trial data published last month in The Clinical Journal of Pain reported that daily, long-term herbal cannabis treatment is associated with improved pain relief, sleep and quality of life outcomes, as well as reduced opioid use, in patients unresponsive to conventional analgesic therapies.
The results of a 2015 Canadian trial similarly concluded that chronic pain patients who consumed herbal cannabis daily for one-year experienced reduced discomfort and increased quality of life compared to controls, and did not possess an increased risk of serious side effects.
Separate data published in 2014 in The Journal of the American Medical Association determined that states with medical marijuana laws experience far fewer opiate-related deaths than do states that prohibit the plant. Investigators from the RAND Corporation reported similar findings in 2015, concluding, “States permitting medical marijuana dispensaries experience a relative decrease in both opioid addictions and opioid overdose deaths compared to states that do not.” Clinical data published in 2011 in the journal Clinical Pharmacology & Therapeutics previously reported that the administration of vaporized cannabis “safely augments the analgesic effect of opioids.”
An abstract of the University of Michigan study, “Medical cannabis associated with decreased opiate medication use in retrospective cross-sectional survey of chronic pain patients,” appears online here.
Cannabis-influenced driving performance is significantly different from alcohol-induced driving behavior, according to driving simulator data published in the Journal of Applied Toxicology.
Investigators with the National Institute on Drug Abuse and the University of Iowa evaluated simulated driving performance in subjects following their consumption of vaporized cannabis, alcohol, or placebo.
Researchers reported that cannabis administration was associated compensatory driving behavior, such as decreased mean speed and increased mean following distance, whereas alcohol administration was associated with faster driving. Their findings are similar to those of other driving studies, like those here and here.
Investigators also reported that cannabis dosing in combination with low quantities of alcohol “mitigated drivers’ tendency to drive faster with alcohol” – a finding that contrasts with prior data acknowledging that the two substances combined typically possess an additive adverse effect on psychomotor performance.
“THC concentration-dependent associations with decreased speed, increased time below the speed limit and increased following distance suggest possible awareness by drivers of potential impairment and attempts to compensate,” authors concluded. “The compensatory behavior exhibited by cannabis-influenced drivers distinctly contrasts with an alcohol-induced higher risk behavior, evidenced by greater percent speed.”
According to the findings of a recently published literature review of crash culpability studies, “[A]cute cannabis intoxication is related to a statistically significant risk increase of low to moderate magnitude [odds ratio between 1.2 and 1.4].” By contrast, a 2015 case-control study by the US National Highway Traffic Safety Administration reported that driving with legal amounts of booze in one’s system is associated with a nearly four-fold increased crash risk (odds ratio = 3.93).
An abstract of the study, “Cannabis effects on driving longitudinal control with and without alcohol,” appears online here.
The enactment of statewide laws permitting the physician-authorized use of cannabis therapy has not stimulated increases in marijuana use by young people, according to findings published in The International Journal on Drug Policy.
A team of researchers from Columbia University in New York City reviewed federal data regarding rates of self-reported, monthly marijuana use among 12 to 17-year-olds between the years 2002 and 2011.
While the study’s authors acknowledged that many medical marijuana states possess greater overall rates of youth cannabis use compared to non-medical states, they affirmed that these jurisdictions already possessed elevated use rates prior to changes in law, and that the laws’ enactment did not play a role in influencing youth use patterns.
“While states with MML (medical marijuana laws) feature higher rates of adolescent marijuana use, to date, no major U.S. national data set, including the NSDUH (US National Survey on Drug Use in Households), supports that MML are a cause of these higher use levels,” investigators concluded. “[W]hen within-state changes are properly considered and pre-MML prevalence is properly controlled, there is no evidence of a differential increase in past-month marijuana use in youth that can be attributed to state medical marijuana laws.”
Their findings are similar to those of a separate 2015 study assessing the relationship between state medical marijuana laws and rates of self-reported adolescent marijuana use over a 24-year period in a sampling of over one million adolescents in 48 states. Researchers in that study reported no increase in teens’ overall cannabis use that could be attributable to changes in law, and acknowledged a “robust” decrease in consumption among 8th graders. They concluded “[T]he results of this study showed no evidence for an increase in adolescent marijuana use after the passage of state laws permitting use of marijuana for medical purposes. … [C]oncerns that increased marijuana use is an unintended effect of state marijuana laws seem unfounded.”
The abstract of the study, “Prevalence of marijuana use does not differentially increase among youth after states pass medical marijuana laws: Commentary on and reanalysis of US National Survey on Drug Use in Households data 2002-2011,” appears online here.