Aaron E. Carroll is a professor of pediatrics at Indiana University School of Medicine. He blogs on health research and policy at The Incidental Economist, and you can follow him on Twitter at @aaronecarroll.
NEW YORK: As my children, and my friends’ children, are getting older, a question that comes up again and again from friends is this: Which would I rather my children use — alcohol or marijuana?
The immediate answer, of course, is “neither.” But no parent accepts that. It’s assumed, and not incorrectly, that the vast majority of adolescents will try one or the other, especially when they go to college. So they press me further.
The easy answer is to demonize marijuana. It’s illegal, after all. Moreover, its potential downsides are well known. Scans show that marijuana use is associated with potential changes in the brain. It’s associated with increases in the risk of psychosis. It may be associated with changes in lung function or long-term cancer risk, even though a growing body of evidence says that seems unlikely. It can harm memory, it’s associated with lower academic achievement, and its use is linked to less success later in life.
But these are all associations, not known causal pathways. It may be, for instance, that people predisposed to psychosis are more likely to use pot. We don’t know. Moreover, all of these potential dangers seem scary only when viewed in isolation. Put them next to alcohol, and everything looks different