...Among those ages 13 to 18, the rate of use increased by 6.5% annually, rising from 2.3% (95% CI 1.5 to 3.1) in 1996 and reaching 5% (95% CI 3.9 to 6.1) by 2008 (P<0.001), the researchers reported online in the American Journal of Psychiatry.
Some 9% of children ages 6 to 17 at some time have been diagnosed as having ADHD. Prescribing of stimulant medications rose sharply in the 1990s, and in the subsequent decade numerous new formulations were developed.
"As the market for ADHD medications has expanded, concerns have been raised about the possible misuse and abuse of stimulants, especially because the increase in ADHD diagnoses has been most marked in adolescents," the researchers wrote.
The study also noted that three times as many boys as girls are prescribed the ADHD medication.