The New York Times has a interesting article about the long term consequences to adolescent brains of early drinking. To whit:
In experiments conducted by the Duke team, the reformed rat drinkers learned mazes normally when they were sober. But after the equivalent of only a couple of drinks, their performance declined significantly more than did that of rats that had never tippled before they became adults. The study was published in 2000 in the journal Alcoholism: Clinical and Experimental Research. Other research has found that while drunken adolescent rats become more sensitive to memory impairment, their hippocampal cells become less responsive than adults’ to the neurotransmitter gamma-amino butyric acid, or GABA, which helps induce calmness and sleepiness.
This cellular mechanism may help explain Jack London’s observation, in “John Barleycorn: Alcoholic Memoirs,” that when he was a teenager he could keep drinking long after his adult companions fell asleep.
“Clearly, something is changed in the brain by early alcohol exposure,” Dr. Swartzwelder said in an interview. “It’s a double-edged sword and both of the edges are bad.
“Teenagers can drink far more than adults before they get sleepy enough to stop, but along the way they’re impairing their cognitive functions much more powerfully.”
Alcohol also appears to damage more severely the frontal areas of the adolescent brain, crucial for controlling impulses and thinking through consequences of intended actions — capacities many addicts and alcoholics of all ages lack.
In 2000, Fulton Crews, a neuropharmacologist at the University of North Carolina, subjected adolescent and adult rats to the equivalent of a four-day alcoholic binge and then autopsied them, sectioning their forebrains and staining them with a silver solution to identify dead neurons.
All the rats showed some cell die-off in the forebrain, but the damage was at least twice as severe in the forebrains of the adolescent rats, and it occurred in some areas that were entirely spared in the adults.
Although human brains are far more developed and elaborate in their frontal regions, some functions are analogous across species, Dr. Crews said, including planning and impulse control. During human adolescence, these portions of the brain are heavily remolded and rewired, as teenagers learn — often excruciatingly slowly — how to exercise adult decision-making skills, like the ability to focus, to discriminate, to predict and to ponder questions of right and wrong.
Basically what I heard from this article is that there is concern that early alcohol abuse may cause long lasting receptor, particularly GABA receptor, changes and possibly increased neurotoxicity in adolescent brains. (I am not certain I buy the neurotoxicity bit…I haven’t read the paper but I don’t think that silver staining is a particularly good way to detect apoptosis in neurons.)
Alcohol induced changes may have lasting behavioral consequences due to their direct effects on areas of the brain which are directly responsible for preventing more drinkning. Thus, they drink on, against the current of neurological determinism, borne back ceaselessly into their alcohol soaked pasts.
It makes me kind of happy I was a goody-goody in high school. Now I can drink knowing that as opposed to direct neurotoxicity, I only have to worry about liver failure, vitamin deficiency, Wernicke-Korsakoff syndrome, ulcers, aspiration pneumonia, social dysfunction…
UPDATE: Some of the commenters have expressed some skepticism as to the good intent of this research. Quitter has the folllowing:
So, when they say, 14-year-olds who drink are more likely to be alcoholic it is also quite likely that 14-year-olds who seek out alcohol and binge drink might have a genetic predisposition for that behavior. Any other conclusion kind of defies common sense because it requires you to compare people who start drinking at early ages to those who wait until they’re 21. Now, anyone who has grown up and been to college knows what those who wait until 21 are like. Of course they will never become alcoholics, they’re prudes! Always have been, probably always will be.
I am not quite willing to question the good intent of the researchers yet. I imagine the researchers were people who like most of us raised their hell in college, came very close to loosing something or someone, and would like to see children be safe. Likewise, I don’t think many of them would advocate complete prohibition of alcohol.
But genetics and a slowly declining middle school use of alcohol (as daksya showed) do not in my mind take away from the wisdom in having some programs to encourage kids to delay and limit their drinking. Everything that we know about behavioral genetics particularly behavioral genetics of disease — this IS in part what I study — shows that genetic effects on behavior are important only in particular environmental contexts. It is important to identify biological and environmental risks and try to prevent them to limit behavioral disorders. This does not involve sweeping kids into anti-alcohol camps gestapo-style, but it does involve acknowledging that if they drink early that will have lasting consequences. Similarly, a declining rate is not a zero rate — even 6% of 8th graders hurting their own brains can be a cost on society.
UPDATE: Corpus Callosum adds in reference to quitter’s comment:
There probably is some truth to that (although I personally would not phrase it so stridently). It sure is a lot easier to get funding for a study that might deter substance abuse, than it is to get funding for a study on medical uses of cannabis.
My own cynicism leads me to comment of the conclusion in the abstract of the JPAM article: “There is a need to screen and counsel adolescents about alcohol use and to implement policies and programs that delay alcohol consumption.”
It would be hard to argue with those points. However, the article does not really support the last point. While they do show that earlier onset of drinking is associated with a worse prognosis, that does not show that getting a kid to delay the onset of drinking will improve the prognosis. A completely different kind of study would be needed to show that.