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".