I’m thinking about the current craze to normalize and even legalize marijuana. As we all know, marijuana goes by many different labels—weed, pot, joints, and dope, to name a few. Not to sound too politically incorrect but I think “dope” is the best nickname since that’s exactly what it does to your brain—it makes you stupid. The popular folklore is that marijuana is not addictive nor harmful so somehow that makes it safe. But even a quick look at the medical literature shows that neither is true; it can be addictive and it’s not safe. It’s not just the medical world that’s picked up on this. Just last week National Geographic magazine ran a summary of multiple health hazards associated with the new marijuana craze.
Its nickname, “dope,” is well earned. A study in Neuropsychology showed that cannabis users performed worse on cognitive tests (fancy jargon for how smart you are), especially in attention and memory tasks, and teenagers who start smoking “joints” earlier in life did more poorly than those who started using it later or nonusers. Long-term cannabis users’ IQs declined by 5.5 points on average, with deficits noted in learning and information processing speed compared to people who didn’t use cannabis. Politely put, the more participants used dope, the greater the resulting cognitive impairment; in plain lingo, the more you smoke the dumber you get. A study published in JAMA Pediatrics last year looked at half a million students and found that dope smoking caused “lower school grades, less likelihood of high school completion, less university enrollment and postsecondary degree attainment, increased school dropout rates, and more frequent school absenteeism.” That’s a poor prognosis for our future generations.
Society’s push for normalization has propelled use quickly. According to data from the Substance Abuse and Mental Health Services Administration’s National Survey of Drug Use and Health, more than 36 million Americans 12 and older reported using cannabis in the past month, double the number compared with a decade ago. The World Health Organization reported that worldwide more than 200 million people are walking around the planet (or worse, flying around the planet) stoned. I think I’ve spent all of my “political incorrectness” capital already so I’ll leave the interpretation of this up to you.
The chemical in cannabis that causes the mind-altering effects is THC, a pronounceable acronym for “delta-9-tetrahydrocannabinol.” In addition to THC, today’s “pot” is mixed with all kinds of unknown additives on the street and pure potency has increased more than 10-fold in recent years. Make no mistake, THC is a psychoactive drug, but it has some FDA-approved uses for alleviating pain and muscle spasms in multiple sclerosis patients, symptoms of inflammatory bowel disease (Crohn’s disease), and glaucoma. There are also approved medical uses for treating side effects of chemotherapy-induced nausea and vomiting and stimulating appetite in anorexic and underweight patients such as those with HIV-AIDS and other chronic debilitating illnesses. Frequent THC users can suffer the opposite effect too—there’s a condition called “Cannabis Hyperemesis Syndrome“ (“emesis” is medical speak for vomiting; hyper means “a lot”) that causes abdominal pain, violent and unrelenting nausea, and vomiting. So medical use is also a mixed picture.
Acknowledging these legitimate medical uses for marijuana, THC remains a controlled Schedule 1 class drug under the Controlled Substances Act (CSA; 21 U.S.C. §801) and is regulated by federal authorities. Schedule 1 has some serious drugs in it, stuff like fentanyl and cocaine. Even though many states have legalized possession of limited amounts, marijuana remains illegal under Federal Law 21 U.S.C. Section 844. This law makes it illegal to use, possess, grow, transport, and sell marijuana. There is no exception for the medical or so-called “recreational” use of marijuana in federal law and possession of even a small amount is a federal crime. The reason to know the federal laws as pilots is that the FAA bans any use of, or transport of, cannabis regardless of local and state laws. So the bottom line is that getting ramp checked with THC in your blood or your luggage compartment could cost you your pilot’s license.
The biochemical effect of dope on the brain is profound and pretty scary. THC interferes with brain cell information transfer by altering nerve-to-nerve connections. There are chemical receptors for THC in brain cells, the highest density of these receptors being in areas of the brain involved in abstract thinking, problem solving, and memory—crucial areas like the hippocampus, amygdala, and pre-frontal cortex. According to data published in the journal Stroke, THC affects these parts of the brain by interfering with “neurotransmitter release, synaptic plasticity, and neurodevelopment and leads to cognitive and behavioral abnormalities.” The reason for these “cognitive and behavioral” changes is that these are parts of the brain that we’ve talked about in these pages before that provide us with the knowledge and skills to perform complex and intellectually demanding tasks—like flying airplanes. THC also has pronounced and detrimental structural effects on the brain. Long-term cannabis users showed significantly smaller brain volumes than nonusers in those thinking and problem-solving areas I just mentioned. This is physical evidence that it’s not just a chemical reaction that interferes with brain function but also a physically destructive effect. None of these changes are reversible since the brain doesn’t “grow back” like your hair will after a bad haircut. Obviously, that’s not good for you or anyone else, especially if you’re flying in IMC on a parallel approach with another aircraft on your wing tip.
Another worrisome finding is that chronic pot use can cause schizophrenia, as shown in a Canadian study published just last month in the Journal of the American Medical Association. Their data showed that schizophrenia was almost 15-fold higher in pot smokers than nonusers in a study of more than 13.5 million people. Schizophrenia associated with smoking pot almost tripled from 3.7% before it was legalized to 10.3% after legalization, reflecting increased availability and use. Overall, the incidence of all psychosis-related diagnoses in Canada increased from 30% before legalizing cannabis to 55% after legalizing the drug. This huge jump (almost 100%) is likely multi-factorial but it’s hard to come away from this temporal relationship and not think marijuana plays at least some part. The other modern myth is that THC is not addictive, but this is also not true according to CDC data. Pot addiction is known in the psychiatric world as “Cannabis Use Disorder (CUD),” and there are 5 different diagnoses listed by the most recent American Psychiatric Association Diagnostic and Statistical Manual of Psychiatric Disorders (DSM-5) covering THC addiction. They cite the incidence is about 30% of chronic pot smokers who can’t quit and use progressively more THC, leading to the “degradation of intellectual and living standards that go along with drug addiction.”
We’ve also talked in these pages about the use of driving skills and accident data as a metric of pilot skills. According to the NTSB, compared to 2000, the proportion of U.S. drivers who died in car crashes under the influence of marijuana has increased between five and 10 times based on toxicology testing. Several studies have shown that marijuana use reduces the drivers’ ability to pay attention, particularly when performing multiple tasks (like driving and texting) and slows reaction time to changing road conditions. Data indicates that marijuana-intoxicated drivers notice hazards later or not at all, brake slower, and are unable to focus on completing driving skills. A Canadian study published in September supports the NTSB findings and showed that from 2010 to 2021 the rate of cannabis-involved traffic injuries increased by 475%, from 0.18 per 1,000 traffic injury emergency department visits in 2010 to 1.01 per 1,000 visits in 2021. The FAA translates motor vehicle incidents, accidents, and citations into pilot safety risks and there is a long list of driving infractions that will cost you your pilot’s license under the US Code of Federal Regulations 14 C.F.R. § 61.15(e). That includes being caught driving while impaired on dope. This is for good reason, according to an informative article a few years back appropriately titled “The Wrong Kind of High,” which cited NTSB statistics that showed about 30% of pilots involved in fatal aviation accidents tested positive for a cognitively impairing substance.
Acute THC intoxication can cause cardiovascular effects such as hypotension (low blood pressure), tachycardia (fast heart rate), bradycardia (slow heart rate), irregular heart rhythm, and heart attacks. Next month we’ll devote part two of this deep dive into marijuana specifically to these cardiovascular risks and detail the impact of THC on cardiac health and accelerated aging. Trigger warning—these data are also pretty scary. Until then, never forget that just as there’s no place for alcohol in the bloodstream of anyone in the cockpit, there’s no place for THC either. Stay clean, stay smart, and stay safe!
