Newswise — A new study finds that adults who legally were able to purchase alcohol before the age of 21 in their states are more likely than others are to be alcoholics or addicted to drugs.
Researchers are not certain how to explain the difference, but it is possible that a higher drinking age could cut back on the intensity of alcohol use before the age of 21, said lead study author Karen Norberg, M.D., a research instructor in psychiatry at Washington University in St. Louis.
Regardless of the explanation, the findings suggest “that there are very long-term benefits to a higher drinking age,” Norberg said.
From the Vietnam era until the mid-1980s, many states allowed people to purchase alcohol at the age of 18. However, a federal law pressured states to boost the drinking age to 21, and all did with the exception of Louisiana, which finally followed suit in the 1990s.
In the new study, Norberg and colleagues looked at surveys of 33,869 people born in the United States between 1948 and 1970. They examined the records to see if there were differences in alcoholism and drug abuse rates depending on when states allowed individuals to buy booze.
The study findings appear in an early online edition of the December issue of Alcoholism: Clinical and Experimental Research.
After adjusting their statistics to prevent things like the ethnicity of the respondents from skewing the results, the researchers found that those who lived in states that allowed drinking before age 21 were 1.3 times more likely to have suffered recently from alcoholism. They were also 1.7 times more likely to have had a recent drug abuse problem.
Norberg said lower drinking ages might have a “peer effect,” since that makes it easier to find friends of one’s age to drink with. “If the drinking age is at 21, it will be a little harder to find some friends to go out with. You’ll probably drink less often and have a smaller number of drinks.”
Traci Toomey, an associate professor who studies alcohol use at the University of Minnesota, said the study is “thoughtful” and provides strong evidence that lower drinking ages do lead to more drinking problems later on.
However, she said, “It is not possible to rule out all other potential explanations … given the many intervening years.”
Toomey also cautioned that higher drinking ages are not the only way to reduce alcohol problems in society. Loopholes that allow people under 21 to drink should close, she said, and the excise tax on alcohol should increase.
Alcoholism: Clinical and Experimental Research: Contact Mary Newcomb at (317) 375-0819 or firstname.lastname@example.org or visit http://www.blackwellpublishing.com/journal.asp?ref=0145-6008
Norberg, KE, Bierut LJ, Grucza RA. Long term effects of minimum drinking age laws on past-year alcohol and drug use disorders. Alcoholism: Clinical and Experimental Research 33(12), 2009.