Medical cannabis: A U.S. study finds a 6.9% reduction in absences from work

The medical marijuana could be linked to a decrease in sick leave. That is what a new U.S. study published in the Journal of Workplace Behavioral Health, conducted by researchers from the’University of Georgia.

The researchers analyzed 423 datasets from the Current Population Survey, covering the period from January 1990 to March 2025. Their sample includes 20.3 million people aged 18 to 61, whether they work full-time or part-time.

After comparing the periods before and after the decriminalization of medical cannabis in the various U.S. states, the authors note a reduction of approximately 6.9 % of the probability of reporting a work-related absence for medical reasons.

However, this finding does not hold true for recreational cannabis: researchers found no statistically significant effect of legalization for adults on health-related absenteeism.

Physical occupations that are particularly affected

The observed effect varies greatly by occupation. The most significant reductions are seen in occupations involving repetitive physical exertion and chronic pain.

Among the factory workers, assemblers, and other manual laborers, the likelihood of taking time off for medical reasons thus decreases by approximately 39% following the decriminalization of medical cannabis. It has decreased by 33% among industrial machine operators and by 32% among healthcare workers.

The number of agricultural workers fell by 18%, while the food preparation and construction sectors saw declines of approximately 10 %, respectively. Similar trends were also observed among lawyers, IT professionals, salespeople, and certain managers.

By economic sector, the decline amounted to 31% in durable goods manufacturing and 16% in non-durable goods manufacturing. Agriculture (-16%), personal services (-11%), construction (-9%), and business services (-8%) were also affected.

What is the connection between medical cannabis and sick leave?

The authors propose an explanation primarily related to the symptom management. Legal access to medical cannabis could facilitate the treatment of certain chronic pain conditions or other health issues that may lead to absences from work.

This hypothesis is particularly relevant for physically demanding occupations, where muscle and joint pain or injuries may be more common. The researchers note, however, that they do not have data that would allow them to directly observe individual cannabis use or the health issues being treated.

This phenomenon could also be part of a broader context of treatment substitution. The authors cite, in particular, studies that have linked medical cannabis laws to a decrease in certain opioid prescriptions. However, these are possible mechanisms, not variables directly measured in this study.

A sharper decline among workers with the lowest levels of education

Differences also emerge based on educational attainment. Workers with a high school education or less account for most of the observed effect.

For people who have not completed high school, the decriminalization of medical cannabis is associated with a decrease in 36% on health-related absenteeism when compared to the sample mean.

Researchers also observed slightly greater effects among older workers and men, although the results vary by demographic group.

A study that does not measure cannabis use

These results should be interpreted with caution. The study measures a effect resulting from a change in the law, rather than the direct effect of cannabis use on a specific employee.

Data from the Current Population Survey are based, in particular, on self-reports. Researchers do not know the amount consumed, the frequency of use, or the duration of absences. Nor can they determine precisely which medical conditions are responsible for the absences from work.

Another limitation: employers’ policies are not addressed in detail. In some sectors, drug testing and zero-tolerance policies may continue to apply even after medical cannabis has been legalized in a state.

The study thus adds a new dimension to the debate on Medical Cannabis and Occupational Health, but does not support the claim that cannabis use directly reduces sick leave. Above all, it shows that changes in medical legislation in the United States are associated with a statistically significant decrease in health-related absences from work.