It’s a modern-day question that, honestly, can’t be answered. There’s plenty of research about alcohol’s long-term effect on your brain and overall health. The amount of research regarding marijuana’s long-term effect on brain health, however, is not so ample.
Kent Hutchison, a professor of behavioral neuroscience at the University of Colorado Boulder and co-director of the CU Change Lab, co-authored a study that serves as a conversation starter for which substance is worse. In the study, published in the journal Addiction, researchers looked at brain scans of 853 adults between the ages of 18 and 55 and 439 teenagers between the ages of 14 and 18. Each of the participants reported their alcohol and marijuana use.
The scans revealed that the drinkers’ brains had reduced gray matter and compromised white matter. Gray matter contains the majority of neuron cell bodies and axons and is responsible for helping the brain process information. White matter lies beneath the gray matter. It contains nerve fibers that help neuron cells communicate across different brain regions.
The pot smokers’ brains did not show a reduction or change in either gray or white matter in Hutchison’s study. When gray and white brain matter is reduced, cognitive impairment and memory loss can occur.
But experts are cautious to declare that marijuana is not harmful to the brain based on the evidence of this study.
“Absence of evidence is not the evidence of absence,” said Dr. Christian Hopfer, professor of psychiatry in the Division of Substance Dependence at the University of Colorado School of Medicine and an attending psychiatrist at UCHealth’s CeDAR. “The cannabis story is less clear, and I don’t know if it’s even fair to compare the two substances in the way the media headlines [have done about this study].”
Some of the headlines of articles covering this study included, “Cannabis safer for the brain than booze,” “Weed won’t cause brain damage the way alcohol will, study finds,” and “Cannabinoids are easier on the brain than booze, study finds.”
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Martin Maxwell, LCSW, program coordinator for the Adult Behavioral Health Intensive Out Patient Program at UCHealth Mountain Crest Behavioral Health – Fort Collins wants to see studies on how pot affects people mentally and spiritually.
Since 2012 when voters in Colorado and Washington legalized recreational marijuana, and subsequently seven other states followed, science has been trying to catch up to the law. Years of studies on excessive alcohol use demonstrates its negative effects on brain and general health.
With marijuana, the studies on its effects on brain health are limited and, also, the findings are across the board. Hutchison said that this variety of outcomes with previous studies led him and his team to investigate marijuana’s impacts on brain health and function.
“The problem with these studies on marijuana use is that one will show that cannabis use is related to smaller brain volume matter in the hippocampus, and another will come along and report that cannabis doesn’t affect the hippocampus but it does affect the cerebellum,” Hutchison said. “When you combine all those studies, you see they’re all over the map, which makes them appear spurious.”
Hutchison’s study, he said, was different than other studies in the fact that he looked at gray and white matter across all regions of the brain, and also compared the two vices.
Some people may find the outcomes of his study surprising since pot has long been associated with decreased brain functioning.
Feature Courtesy of the University of Colorado -- Fort Collins -- Medical School