A recently released study conducted at the University of Colorado-Boulder sought to determine the amount of brain damage from cannabis in comparison to brain damage from alcohol. The study found that alcohol consumption is far more damaging to the brain than cannabis. The groundbreaking study was conducted by examining the brain scans of 850 adults and 430 teenagers. Some were given alcohol and others cannabis.

The study revealed that alcohol use correlates to a decrease in both grey and white brain matter. Cannabis use, however, did not produce any noticeable decrease in brain matter. Grey matter controls brain function while white matter controls communication between the nerves in the brain. What is frightening about the destruction of gray and white matter is that any reduction in volume could lead to permanently impaired brain function.


It was already known that cannabis may be able to help treat alcoholism, but a comprehensive study comparing the effects of both in relation to each other had never been conducted. The results of this study directly contradicts the beliefs of many cannabis critics who believe consumption of the plant causes brain damage. Co-author of the study Kent Hutchison stated, “While marijuana may also have some negative consequences, it definitely is nowhere near the negative consequences of alcohol.”

The author of this study, Rachel Thayer, cautioned that studies showing how cannabis affects the brain are few in number and regularly contradict themselves. Hutchison agreed about the volatility of results when studying cannabis. “When you look at these studies going back years, you see that one study will report that marijuana use is related to a reduction in the volume of the hippocampus (the region of the brain associated with memory and emotions), the next study then comes around, and they say that marijuana use is related to changes in the cerebellum or the whatever.”


There are many more brain scan studies evaluating the effect of alcohol use. Most of the published results have come to a consensus that alcohol is very damaging to the brain. It is worth mentioning that until cannabis is reclassified to Schedule 2 or Schedule 3, we are unlikely to see large scale studies on the effect of cannabis on the body and brain.

Though the evidence provided by the University of Colorado-Boulder study may be surprising at first, it does support claims made by many in the cannabis industry that cannabis is far less dangerous than alcohol. Brain health is a concern for many and medical marijuana patients can sleep a little bit better knowing there are far more damaging items out there than medical cannabis.