Long-term alcohol use is more damaging to the brain than long-term cannabis use, new research finds.
The assumption among many scientists has been that cannabis use may be just as damaging to long-term health as alcohol.
But this new study of over 1,000 people’s brains suggests otherwise.
Alcohol use is linked to decreased gray matter size and lower white matter integrity, the researchers found.
Cannabis, though, had no link to reductions in these critical measures of brain health.
Professor Kent Hutchison, study co-author, is sceptical about the research suggesting cannabis is just as bad for the brain as alcohol:
“When you look at the research much more closely, you see that a lot of it is probably not accurate.
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 next study then comes around, and they say that marijuana use is related to changes in the cerebellum or the whatever.
The point is that there’s no consistency across all of these studies in terms of the actual brain structures.”
While some suggest cannabis use can be beneficial, many scientists are hesitant.
Rachel Thayer, the study’s first author, said:
“Particularly with marijuana use, there is still so much that we don’t know about how it impacts the brain.
Research is still very limited in terms of whether marijuana use is harmful, or beneficial, to the brain.”
The study involved people with a variety of different alcohol and cannabis intakes aged 18-55.
Professor Hutchison concluded:
“…while marijuana may also have some negative consequences, it definitely is nowhere near the negative consequences of alcohol.”
About the author
Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology.
He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book “Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks:
- Accept Yourself: How to feel a profound sense of warmth and self-compassion
- The Anxiety Plan: 42 Strategies For Worry, Phobias, OCD and Panic
- Spark: 17 Steps That Will Boost Your Motivation For Anything
- Activate: How To Find Joy Again By Changing What You Do
The study was published in the journal Addiction (Thayer et al., 2017).