Marijuana causes less damage to the brain than alcohol, according to a new study.
Researchers at the University of Colorado in Boulder conducted a study that reviewed imaging data to examine the effects of marijuana and alcohol use on the brain. They found that alcohol consumption can cause long-term alterations to the makeup of white and grey brain matter.
For marijuana users, researchers did not find notable changes to the structure of the brain.
The study was led by Rachel Thayer of the Department of Psychology and Neuroscience at the University of Colorado Boulder. Researchers collected data from 853 adults aged 18-55 and 439 teens aged 14-18. The study findings were published in the medical journal Addiction.
According to the National Institute on Drug Abuse, over 22 million people in the United States have used marijuana in the past month. This makes marijuana the most widely used illicit drug. With positive attitudes toward marijuana rising, it is possible the number of users increases in the coming years.
Even with so many Americans using marijuana, research on its impact has been inconsistent at best. Many studies and patient testimonials have concluded that marijuana is effective to combat a long list of ailments including chronic pain, anxiety/depression, and even opioid abuse.
“When you look at these studies going back years,” he explains, “you see that one study will report that marijuana use is related to a reduction in the volume of the hippocampus. The next study then comes around, and they say that marijuana use is related to changes in the cerebellum,” one of the University of Colorado’s co-authors, Kent Hutchison said.
“The point is that there’s no consistency across all of these studies in terms of the actual brain structures.”
Because marijuana is a Schedule I substance on the Drug Enforcement Agency’s banned list of drugs, conducting research has not been easy.
“With alcohol, we’ve known it’s bad for the brain for decades,” notes Hutchison. “But for cannabis, we know so little.”
Medical marijuana use is legal in 29 states and recreational use is permitted in 9 states. With more states likely to approve both medical and adult-use the need for more research into the long-term effects of marijuana could become even more critical.