As the new year is upon us, and vaccines have finally given us a glimmer of light at the end of the long COVID tunnel that still lies ahead, we would be wise to consider the public health implications of another health policy issue that has become increasingly salient. This past November, voters in several states including New Jersey and Arizona moved to legalize recreational marijuana use, reflective of a national trend toward decriminalization in recent years.
As there is growing consensus that the “war on drugs” has been costly and ineffective, with enforcement patterns that have disproportionately penalized people of color, decriminalizing marijuana is a logical and ethical course of action. However, changes to marijuana policy should be based on science and enacted thoughtfully and judiciously in order to minimize potential harm while protecting individual liberty.
While the concept of marijuana as a “gateway drug” that escalates to more dangerous substance use has been largely debunked, it would be an error to infer it is therefore harmless. Inhaling any burning substance causes lung damage and a cascade of inflammation that significantly increases the risks of cancer and cardiovascular disease. Smoking marijuana in particular has been associated with a nearly five-fold increased risk of heart attack in the hour immediately following.
While vaping marijuana eliminates some of these concerns, this method of delivery has been associated with severe lung injury as well.
As a cardiologist, I have seen firsthand how little the public is aware of the potential cardiovascular risk from smoking marijuana. Accordingly, when counseling patients I urge them to avoid inhalation of any substances and to opt for oral formulations if they express a strong intent to continue using marijuana.
Still, as I emphasize to patients, this is a measure of harm reduction rather than harm elimination, and more research is needed to better understand the chronic effects of marijuana itself. We already know, for example, that heavy chronic marijuana consumption in young people under the age of 25 has been associated with decreased cognitive and executive function.
In addition to risks of self-harm, marijuana may pose a risk of harm to others through inhalation of secondhand smoke or through motor vehicle accidents due to impaired judgment and motor skills.
On the other hand, marijuana derivatives may provide some therapeutic benefit for certain individuals. In patients with advanced malignancy or AIDS, tetrahydrocannabinol can help to regulate mood, suppress nausea, and improve appetite.
In addition, cannabidiol has shown promise as a potential anti-epileptic agent to manage debilitating seizures in children. It has been suggested that broader populations might benefit from cannabis-related effects on mood disorders and chronic pain, but further research is needed in this area to establish whether the benefits outweigh the risks.
Decriminalization of marijuana will create significant opportunities to conduct this research, but common-sense regulation based on science must be implemented simultaneously to create an ethical policy framework. This should aim to promote public health through comprehensive education programs and protection of vulnerable populations such as adolescents, while recognizing the right of autonomous adults to make decisions about their own health but not to act in a way that might compromise the health of others.
Mental health and addiction experts should lead the development of guidelines, such as those published by the American Society of Addiction Medicine, including an age limit of at least 21 to minimize risk of potential harm to young developing brains. Smoking or vaping any substances in public places should be prohibited so as not to impinge upon the liberty of others who do not wish to inhale secondhand smoke, just as there should be strict legal consequences for driving under the influence of substances that may lead to impaired function and increased risk of harm to others though motor vehicle collisions.
On the contrary, possession and use of marijuana by adults that does not directly affect others should not carry significant criminal penalties, particularly as enforcement patterns in practice have only served to entrench systemic racism.
There is substantial need for more research to guide specific policy development going forward, and in the meantime, recreational use (though not medicinal use) should be generously taxed to fund research efforts as well as addiction treatment in order to enhance benefits to society.
As with so many current issues, the rhetoric regarding marijuana use has too often been subservient to political agendas, with some conservatives condemning it as dangerous and criminal, while some liberals – and aspiring marijuana entrepreneurs – want to exonerate it as completely benign.
Instead, a nuanced and fact-based approach is necessary to promote the dual moral imperatives of personal liberty and harm reduction.
Sarah C. Hull, MD, MBE, is a cardiologist at Yale School of Medicine and associate director of its Program for Biomedical Ethics.
Last Updated January 15, 2021