Genetic Risk for Cannabis Addiction Linked to Severe COVID-19 Outcomes

A team of researchers has identified a genetic link between susceptibility to cannabis use disorder and the risk of severe COVID-19 outcomes, a finding that opens new questions about how our genes shape our vulnerability to the virus. The study, published in Biological Psychiatry Global Open Science, examined the genomes of over 1.2 million people infected with COVID-19 and found that genetic variants associated with problematic cannabis use account for roughly 38 percent of the genetic risk factors that predict who will need hospitalization.

The work began with a specific biological observation: cannabinoid signaling—the way cannabis compounds interact with our cells—plays a documented role in regulating immune responses. Researchers wondered whether the genes that predispose someone to cannabis use disorder might also influence how severely the body responds to COVID-19 infection. To test this, they analyzed genetic data from 343,726 individuals, including 14,080 people diagnosed with cannabis use disorder, then cross-referenced those findings against data from the COVID-19 Host Genetics Initiative, which tracks infection outcomes across more than a million people.

The correlation they found was striking. Across roughly 7 million genetic variants examined, those linked to cannabis use disorder—a condition marked by persistent desire to use cannabis and inability to cut back—showed a measurable association with hospitalization risk. But the researchers were careful to emphasize what their findings do not prove. Possessing these genetic variants does not mean someone will develop cannabis use disorder, nor does it mean that actually using cannabis causes worse COVID outcomes. The connection is genetic, not behavioral.

Alexander Hatoum, one of the study authors, explained the logic this way: if we can identify the genes that predispose people to cannabis use disorder, and if those genes correlate with severe COVID outcomes, then those genes become predictive markers for who might face greater risk. The implication is that some shared biological mechanism—possibly related to immune regulation—links the two conditions, rather than cannabis use itself being the culprit.

This distinction matters enormously for public health. Previous research has already identified genetic susceptibility to diabetes, obesity, and hypertension as risk factors for severe COVID, allowing doctors to monitor high-risk patients more closely. If genetic profiling for cannabis use disorder vulnerability proves useful, it could help officials identify and protect another vulnerable population. Yet the researchers themselves acknowledge uncertainty about whether cannabis use disorder actually causes worse COVID outcomes or whether both conditions simply stem from the same underlying biological vulnerabilities.

In their published findings, the team noted that genomic causal models did not definitively support the idea that cannabis use disorder directly causes severe COVID hospitalization. The relationship appears more subtle—a shared genetic architecture that influences both conditions through pathways not yet fully understood. Hatoum suggested that the research "raises the intriguing possibility that heavy and problematic cannabis use may contribute to severe COVID-19 presentations," and that addressing problematic cannabis use might help reduce COVID severity. But he stopped short of claiming proof.

The study represents the kind of genetic detective work that has become central to understanding COVID-19 vulnerability. By mapping the genetic landscape of who gets sicker, researchers give public health officials tools to identify at-risk groups and clinicians information to guide treatment decisions. Yet it also illustrates how genetic correlation can be tantalizing and incomplete—a signpost pointing toward biological truth without yet revealing the full picture.