A response to NPR's misinformation regarding THC potency

On May 15, 2019, the National Public Radio (NPR) program All Things Considered included a segment about high-potency cannabis. A corresponding article, "Highly Potent Weed Has Swept the Market, Raising Concerns About Health Risks," was posted to NPR's website. Unfortunately, NPR presented a one-sided view of the topic and made assertions that are not supported by the available evidence. We are reproducing below the letter that ASA's William Dolphin sent to NPR in response to this misleading segment.


Dear Ms. Chatterjee and the producers of All Things Considered,

I'm writing in response to your piece today "Highly Potent Weed Has Swept The Market, Raising Concerns About Health Risks," as I trust NPR to present a balanced, thoughtful look at issues of importance, but this was an exception. Yes, it is accurate to say that some health professionals have raised concerns about purported changes in cannabis product potency, but there is far more to this story, which interviews with other experts more conversant with cannabinoid medicine and history would have revealed.  As it is, this piece fosters misconceptions about the relative risk of cannabis use by failing to contextualize its claims.

There is nothing new or inherently more dangerous about cannabis products that are more potent than others. High-potency extracts such as hashish have been commonly available for centuries in many parts of the world. There has been a change in average potency of seized and even available products as cultivators and manufacturers have improved techniques, but that just means users have to consume less of the product to obtain the dose sought. This is a health benefit for people who use smoking as a mode of delivery, as most still do, because it reduces the uptake of the attendant tars and other smoke byproducts that are a potential risk to the bronchia and lungs. Higher-potency also benefits consumers financially by reducing the per-dose cost of the products.

Regardless of potency, the active chemicals are the same: cannabinoids and terpenes. Delta-9 Tetrahydrocannabinol (THC) is, as you noted, the most prevalent and psychoactive, but the percentage of THC in a given product doesn’t alter the chemical's effects – the dose does. Each of the problematic cases mentioned in your piece involve mistakes of dosing in which an individual misses the mark on titration and ends up either more intoxicated than expected or, in the case of the pain patient, with hyperalgesia instead of analgesia. Yes, THC produces dose-dependent effects which in the case of pain and sometimes anxiety is bi-phasic, typically reducing pain or anxiety at low to moderate doses and potentially exacerbating it at higher doses.

Start low and go slow is the guiding principle for most all medications, and cannabinoid medicines are no different. Anyone who follows that advice are more likely to avoid those negative effects, as they will with other medications. This dosing consideration is relatively unremarkable, except that cannabinoid medicines differ dramatically from almost all others in their relative safety profile. The science is unequivocal that, no matter how high a dose anyone takes on board, no lasting physical harm will result, and a fatal overdose is impossible. This means that “[i]n strict medical terms marijuana is far safer than many foods we commonly consume,” as the DEA’s Chief Administrative Law Judge Francis L. Young noted in his 1988 ruling on cannabis rescheduling. That safety profile suggests alarm is unjustified.

You suggest Cannabis Hyperemesis Syndrome (CHS) may be cause for alarm, but it is an extremely rare side effect of chronic cannabis use in a small set of people that does not appear to be related to any particular cannabis product, route of administration, or potency. Uncontrolled vomiting poses a significant health risk no matter what the cause, but in the case of cannabis-induced hyperemesis, the vomiting can be mitigated by hot showers or baths, and it disappears quickly with cessation of cannabis use. Your piece says death can result, which is indeed true of all uncontrolled vomiting, but compared to other causes of severe vomiting, CHS is easily managed. A recent article identifies only two cases in which individuals with vomiting and cannabis in their systems died (J Forensic Sci. 2019 Jan;64(1):270-274), but one case involved excessive vomiting (10x/day) that went untreated over 5-6 days, and the other individual had an 8-year history of vomiting problems. Any claim that connects these two cases to change in cannabis potency is unsupported, and the implication that more potent cannabis may lead to death is false. The ellipsis in the quote from Andrew Monte used to make this claim ("Some people have died from this ... syndrome, so that is concerning.") raises suspicion that the original may have been a more qualified claim. The following sentence is even more egregious when it says “[s]cientists don't know exactly how high levels of THC can trigger the syndrome” – implying that it’s an established fact that it does, but we just don’t understand the mechanism of action. That claim is false and unsupported by any information from which it might even be a reasonable inference. 

Similarly, the account of an increase in ER visits with cannabis use as a factor receives no critical context. While it’s possible that changes in products or inadequate labeling may contribute to dosing mistakes that lead to more ER visits (though again, no injury results from those mistakes and no treatment is typically entailed), there is another obvious possibility. So long as cannabis use is illicit, people are less likely to present themselves for medical attention. This has been documented in public health studies of the negative effects of the criminal justice approach to drug abuse (e.g. Drucker, E. “Drug Prohibition and Public Health: 25 Years of Evidence.” Public Health Rep. 1999 Jan-Feb; 114(1): 14–29.). So, since Colorado has made all adult use legal, people may well be more willing to seek medical attention if concerned about a cannabis side effect, since they don’t risk arrest in doing so. It is not conclusive evidence of increased risk; in fact, it may well be evidence of decreased risk, as individuals may receive reassurance and education that will protect them against future adverse experiences.  

Lastly, the concern for mental health impacts misrepresents what is known about associations between cannabis use and such disorders. Many people with psychiatric problems self-treat with a variety of substances prior to or even while receiving formal mental health treatment. In the case of schizophrenics, those individuals universally report subjective symptom relief. Indeed, cannabinoids hold considerable promise as *antipsychotics*. A clinical trial in Germany with refractory schizophrenics finding that treatment with high-dose CBD was as effective as the most powerful pharmaceutical antipsychotics in controlling their symptoms, with none of the negative side effects. In other words, there is good reason to think that the association between mental health disorders and cannabis use poses a chicken-and-egg problem: which comes first? Since few people seek immediate psychiatric treatment at the first signs of a mental health problem (and many with severe problems resist treatment), it is fair to guess that self-treatment is occurring prior to diagnosis.

In the future, it is my hope that you will present a more complete and balanced account of issues such as this. Interviews with more relevant experts can help, so I will take the liberty of suggesting a few:

Please also feel free to contact me or Michelle Newhart, PhD, my coauthor of The Medicalization of Marijuana: Legitimacy, Stigma, and the Patient Experience (Routledge). https://www.newhartdolphin.com/.

Thank you for your consideration,

William Dolphin