The journal Clinical EEG and Neuroscience has just published a review of the data on the effects of substance use on the developing brains of adolescents. The unmistakable conclusion: While heavy substance use of any kind is a really bad idea for teens, the damaging effects of alcohol are clearly worse than marijuana. The researchers write:
Abnormalities have been seen in brain structure volume, white matter quality, and activation to cognitive tasks, even in youth with as little as 1-2 years of heavy drinking and consumption levels of 20 drinks per month, especially if >4-5 drinks are consumed on a single occasion. Heavy marijuana users show some subtle anomalies too, but generally not the same degree of divergence from demographically similar non-using adolescents.
Strikingly, in a couple of studies, the damaging effects of binge drinking were less if the drinker also used marijuana, suggesting — though not proving — a possible protective effect in some circumstances. That’s actually no shock, as the U.S. government holds a patent on cannabinoids — marijuana’s unique, active components — as neuroprotectants (substances that protect nerve and brain cells from damage).