Adults who initiate alcohol and marijuana use before the age of 21 are much more likely to abuse or become dependent in later years

Early onset of alcohol use is associated with a greater likelihood of developing alcohol abuse or dependence at a later age, according to data from the US National Survey on Drug Use and Health (NSDUH).

Those who first used alcohol at or before the age of 14 were nearly four times more likely to meet the criteria for past year alcohol abuse or dependence than those who started using alcohol between the ages of 18 and 20 (16.5% vs. 4.4%) and more than six times more likely than those who started using alcohol at or after age 21 (16.5% vs. 2.5%).

These findings illustrate the need for alcohol education and prevention efforts as early as middle school.


Percentage of Adults (Ages 21 or Older) Who Abused or Were Dependent on Alcohol in the Past Year, by Age of First Alcohol Use, 2009.

Similarly, adults who first started using marijuana at or before the age of 14 are most likely to have abused or been dependent on illicit drugs in the past year. Adults who first used marijuana at age 14 or younger were six times more likely to meet the criteria for past year illicit drug abuse or dependence than those who first used marijuana when they were 18 or older (12.6% vs. 2.1%) and almost twice as likely as those who started between the ages of 15 and 17 (12.6% vs. 6.6%).


Percentage of Adults (Ages 21 or Older) Who Abused or Were Dependent on Illicit Drugs in the Past Year, by Age of First Marijuana Use, 2009.

Links:
Adults Who Initiate Alcohol Use Before Age 21 More Likely to Abuse or Become Dependent on Alcohol - CESAR FAX, University of Maryland, USA.
Early Marijuana Use Related to Later Illicit Drug Abuse and Dependence - CESAR FAX, University of Maryland, USA.