Does The Latest Brain Study Vindicate The 21 Drinking Age? Well, Not Exactly.

There is a new brain study making the headlines these days.  This study examined postmortem brains of three groups of people:  1) 11 people with alcohol use disorders (AUD) who began drinking consistently before age 21, 2) 11 people with AUD who began drinking consistently after age 21, and 3) 22 people who did not have any AUD at all, though many of them drank at least somewhat.  And among the three groups, only for the early-onset AUD group were epigenetic changes related to the expression of brain-derived neurotrophic factor (BDNF) found, particularly in the amygdala, which is responsible for regulating emotions.  These changes are thought to lead to difficulty regulating emotions, problems with anxiety, and even be part of the pathophysiology of alcoholism itself.

So what does this really mean, exactly?  First of all, the researchers seem to have arbitrarily picked 21 as the dividing line between early-onset and late-onset AUD drinkers, and made no further distinction within the early-onset group (i.e., before 15, before 18, first drink, first drunkenness, first regular drinking, etc.).  Secondly, the study looked at a small sample size of people with alcohol-use disorders (think alcohol abuse/dependence, alcoholism, truly heavy, heavy drinking for many years or decades), who at the time of death averaged well over 10 standard drinks per day and over 100 drinks per week, over 30+ years.  Males were also overrepresented (in fact there were zero women in the early-onset AUD group), and the early-onset group drank significantly heavier then the late-onset group.  It is probably safe to say that these drinkers are NOT representative of the vast majority of those who drink before 21, and given how early the onset of early-onset AUD drinkers tends to be, it would also be safe to say that this early-onset AUD group largely began drinking well before 18, if not before 15.  And even among the late-onset AUD group, the relative lack of epigenetic changes certainly did NOT stop them from becoming alcoholics in any case.

Furthermore, there is no temporality to this non-longitudinal study, so we don't know whether or not these epigenetic changes were due to pre-existing vulnerability or perhaps the early use of other substances such as that now-infamous neurotoxin, nicotine. (Most of the study subjects were smokers, apparently, and about 90% of adult regular smokers typically begin smoking before age 18).

Thus, this study tells us NOTHING about the difference between people in general who begin drinking at 18 versus 21.  NOTHING.  Nor does it vindicate the ageist abomination that is the 21 drinking age.  And anyone who claims otherwise is being, shall we say, "economical with the truth".

Latest Teen Brain and Cannabis Study More Smoke than Fire

The scary-sounding headline from a few weeks ago in USA Today reads, "Marijuana caused more damage to teens' brains than alcohol, study finds".  Yes, there was a study that claimed to find such results, but there is less here than meets the eye.

In other words, there's more smoke than fire.

The actual study itself is predictably behind a paywall, and we will not dignify such questionable research by paying for it, so we couldn't find the actual numbers and thus could not quantify any effect sizes or how long the reported effects lasted, but the abstract and several news articles summarize qualitatively the main findings.  The study, which involved nearly 4000 students from 7th through 10th grades in the greater Montreal area, longitudinally following them for those four years, asking questions about both alcohol and cannanis use and giving tests on memory and response inhibition.  Statistically significant correlations were noted between increased cannabis use and reduced performance on such tests, while interestingly for alcohol such correlations failed to reach statistical significance.

Again, no information about the size of such reported effects, and guess what?  SIZE MATTERS.  And so does duration.  Also, it say nothing about any such correlations beyond 10th grade, nor clearly distinguish between lighter and heavier use.  (The article did note that there were many more daily users of cannabis than alcohol, despite the fact that there were many more drinkers than tokers overall the sample.)  And it is very curious that the typically pro-21 mainstream scientific community are so willing to practically exonerate alcohol in such a study of teens--or perhaps they are simply alcohol supremacists.  And while the sample size and longitudinal nature of this study puts it head and shoulders about most other studies on the matter, given the aforementioned concerns it should still be viewed with caution in terms of causation.

Additionally, the study seems to be silent on the real "dark horse of drugs"--tobacco/nicotine.  Nicotine is a known neurotoxin, particularly during early adolescence, and is far more correlated with cannabis than alcohol use.  Thus, at least some of the reported effects in the study could in fact be due to tobacco, and/or perhaps other substances as well.

Keep in mind that the infamous 2012 study that reportedly found persistently reduced IQs among adults who used cannabis before age 18, was debunked by 2014 study that found no correlation between adolescent cannabis use and IQ or exam performance (though heavy use beginning before age 15 was associated with slightly poorer exam results at age 16).  This latter study did control for tobacco, alcohol, and a host of other factors.  So it is very likely that soon another study will come a long and refute the first study discussed in this article, or perhaps find that any such effects are limited to the heaviest users, particularly those who began before age 15 or 16.  In fact, a 2018 systematic review of 69 studies of adolescent and young adult cannabis use and cognitive functioning found that reported adverse effects were much smaller in size than the prohibitionists like to claim, and generally tend to be temporary rather than permanent, even for frequent and/or heavy use.  And interestingly, no correlation with age of onset, though the mean age of study participants in these 69 studies was significantly higher than in the aforementioned Montreal study.

Other studies as well cast serious doubt on the scary claims of cannabis neurotoxicity as well, and most studies find weed safer than alcohol.

So what is the best takeaway from such studies?  It would seem that while occasional or moderate cannabis use is basically a non-problem, heavy and/or daily/near-daily use (unless medically necessary) should probably be avoided at any age, but particularly for people under 18 and especially under 15.  And while delaying the onset of use, or at least regular use, for as long as possible is probably wise for people under 18 and especially under 15, there is no hard scientific evidence that cannabis is any more harmful at 18 than it is as 21, 25, or even 30 for that matter.  Thus, there is no good reason to keep it illegal or set the age limit any higher than 18.  And even for people well under 18, the criminal law is still far too harsh a tool to apply to something like this that more likely than not turns out to be a non-problem.

Which Ancillary Laws Actually Work to Reduce Teen Drinking? (Spoiler Alert: Almost None)

The legal drinking age (at least in terms of purchase and public possession) has been 21 in all 50 states and DC since 1988 (notwithstanding the Louisiana Loophole through 1995), but states and localities have differed since then on the "ancillary" laws that are used to prop up the 21 drinking age.  These laws include, among others:

• Laws against private possession and/or consumption 
• Internal possession laws
• Laws against furnishing alcohol to people under 21
• Dram shop liability laws
• Social host liability laws (civil or criminal)
• Keg registration 
• Use alcohol and lose your license ("use and lose" laws)
• Zero-tolerance laws for DUI
• Fake ID laws and ID scanner laws
• Age limits for serving alcohol

Most if not all of these laws have been studied to some extent, with mixed results and even some serious plot twists.  Most of these studies have been conducted by MADD-affiliated researchers such as James C. Fell, Robert Voas, and Ralph Hingson, so they should probably be taken with at least a grain of salt, if not a whole pound.  But even with this potentially significant bias, most of these laws were found to have either no effect, inconsistent effects, very small effects, or even perverse effects in terms of "alcohol-related" traffic fatalities among young people.

If these laws (and by extension, the 21 drinking age itself) did work as intended, one would expect the effectiveness of these laws to show up not only in traffic fatality statistics (which are the tip of a very large iceberg), but also in surveys of teen drinking as well, especially when recent data are studied.  A 2014 study done by Vanessa H. Sacks et al. of Child Trends examined the relationship between 14 different ancillary laws (and alcohol taxes) and both current drinking (any in the past 30 days) and "binge" drinking (5+ drinks "within a couple of hours") among high school students from 2005-2011 as reported on the Youth Risk Behavior Survey (YRBS) of those years.  The 14 laws studied were the following:

• Laws against consumption of alcohol by people under 21
• Exceptions to possession laws
• Exceptions to furnishing laws
• Social host liability laws 
• BAC limits for people under 21 (i.e. zero-tolerance laws)
• Use-and-lose laws (strength measured in three different ways)
• ID scanners in retail locations
• Keg registration
• Age limits for serving alcohol 
• Beer excise taxes in 2005
• Distilled spirits excise taxes in 2005

And the results?  All but three such laws had no significant or even perceptible effect individually on either current drinking or "binge" drinking rates.  The only three that did have any statistically significant correlation were:

• Beer taxes were significantly and negatively associated with both current drinking and "binge" drinking rates.  No surprise there, as this dovetails nicely with the reams of evidence that have found similar results.  (Distilled spirits taxes showed no correlation either way, but that apparently null result is likely due to multicollinearity since beer and liquor taxes are highly correlated with each other).
• Keg registration laws were significantly and negatively correlated with current drinking, but not "binge" drinking, in one of two models.  This result should probably be interpreted with caution though, given how multiple other studies have found a positive correlation between keg registration and "alcohol-related" youth traffic fatalities.
• Use-and-lose laws (i.e. driver's license penalties for mere possession or consumption of alcohol) showed a positive correlation with current drinking, that is, such laws seemed to perversely increase teen drinking.
• And the real kicker: after controlling for drinking rates in previous years and the number of ancillary laws in previous years, states with a greater total number of such policies perversely had higher rates of both current and "binge" drinking.  But drinking rates in previous years did not predict the number of policies in place in later years, thus ruling out the possibility of reverse causation.

Thus, while the researchers caution that these results alone are not definitive enough to establish causation, it is quite clear that such results certainly cast serious doubt on the effectiveness of such laws, and by extension the 21 drinking age itself, in reducing teen drinking and related problems.  With the notable exception of alcohol taxes, the effects of such laws are most likely negligible or even perverse overall.  That, of course, dovetails rather nicely with Miron and Tetelbaum (2009), who found that raising the drinking age to 21 seems to have had "only a minor impact on teen drinking".  And we couldn't agree more.