Wednesday, October 2, 2013

Extreme Binge Drinking Revisited

The latest news on extreme binge drinking is in.  Apparently, a new study of Monitoring the Future (MTF) survey data from 2005-2011 found that about one in ten high school seniors have engaged in "extreme" drinking, defined as 10 or more drinks in the same occasion at least once in the past two weeks.  And about one in twenty have consumed 15+ drinks (!) in the same timeframe.  Rates were highest in the Midwest and in rural areas (i.e. so-called "blue-collar America"), and more common among males than females.  We have already noted similar findings four years ago.

While clearly only a small minority in engaging in such truly dangerous drinking, it is not a trivial fraction either, and is probably an underestimate.  And, most relevant to the drinking age debate, these numbers have not changed significantly since MTF began following them in 2005, despite ever-intensifying enforcement of the 21 drinking age and its ancillary laws.  So recent declines in prevalence of 5+ drinks in a row appear to be somewhat misleading, especially since underage drinkers tend to undercount their drinks.  Lying (or exaggerating or minimizing) is also fairly common in teen drug and alcohol surveys.

For what it's worth, according to the same surveys about 25% of seniors and 18% of sophomores admit to having had 5+ in a row in the past two weeks, and these numbers are leveling off after a decade-and-a-half-long decline.  It seems that fewer teens are drinking, but the more they do when they do.  That may explain why in emergency rooms in several cities across the country, admissions related to teen binge drinking increased in recent years in spite of surveys showing that teen drinking and "binge" drinking are both at record lows.

Tracking this highly dangerous behavior is long overdue.  We already know that among college freshmen, 20% of males and 8% of females have done extreme drinking (10+ males, 8+ females) in the past two weeks.  But that was a one-semester snapshot in the fall of 2003, with no other years for comparison.  The rate of "binge" drinking (using the 5/4 definition) in the past two weeks was 41% for males and 34% for females, which does jibe well with known statistics (roughly 40%) that use that definition.  But one must wonder if there is even any relationship at all between the rates of drinking, "binge" drinking, and "extreme" drinking.  And it is an important distinction to draw, as studies show that a higher cutoff (e.g. 7/6 or 8/6) has better predictive value for the more serious alcohol-related problems than the rather unscientific 5/4 definition.

Indeed, from 1993 to 2005, the percentage of college students who "binge" drank (5/4 definition) in the past two weeks has not changed a whole lot, but the percentage who do so three more times in the past two weeks ("frequent binging") has gone up significantly.  And since the aforementioned study found that extreme drinking was strongly correlated with frequent "binging," the former most likely rose as well.  Further evidence comes from another study that found that the number of alcohol poisoning deaths (a good indicator of truly dangerous drinking) among college students nearly tripled from 1998 to 2005. 

Bottom line:  when you criminalize normative drinking, you inevitably normalize truly dangerous drinking.  We saw the same thing during Prohibition.  And we all pay a heavy price for it.