The use of illicit drugs has declined slightly over the last decade among teens but is growing more common in people over age 50. New data from the U.S. Substance Abuse and Mental Health Services Administration show that 23.9 million Americans over age 12 had used drugs in the previous month. Marijuana use is most common and rose from 5.8 to 7.3 percent of people over 12 from 2007 to 2012. The trend over age 50 reflects the entry into the age group of the baby boom generation, with higher drug-use rates than older generations, researchers say.
