Opponents of marijuana legalization often say that marijuana is harmful to the brain. As a result, those who could benefit from medical marijuana's therapeutic properties may stay away from the medication for fear that it may kill brain cells, but scientists and physicians now understand this is not true. Studies that have focused on marijuana use and the brain have not discovered permanent changes in the brain as a result of long-term marijuana use. Researchers from the University of California, San Diego, analyzed the findings of 15 studies on marijuana and cognitive function, data that included over 1,000 test subjects, and found marijuana users merely suffered from temporary minor impairments in learning and memory. Another study from the University of Colorado Boulder in 2015 compared the brain scans of marijuana users to non-users, and researchers found no physical differences in the major areas of the brain.
Contrary to the notion that marijuana might harm the brain, evidence suggests medical marijuana may actually have positive long-term effects on the brain. Cannabinoids have antioxidant and neuroprotective properties that may be beneficial for brain damage, and could help in the treatment of degenerative brain disorders like Alzheimer's and Parkinson's disease. Studies on animals have even found THC and CBD may even stimulate neurogenesis, or brain cell growth. While there is no evidence of long-term harmful use on the brain, caution should be used during adolescence when the brain is still developing. There is no quantifiable evidence of the harm marijuana might have during this time, but as the brain develops it is more susceptible to negative effects of drug use. Researchers also suggest avoiding smoking marijuana. While marijuana itself may not harm the brain, smoking deprives parts of the brain of oxygen, which could negatively impact brain cells.
This information has been provided by Leaf Science and approved by our Chief Medical Officer.