By Robert Preidt
"We need to have a realistic understanding of when young people are beginning to experiment with stimulants, so we can prevent them from misusing for the first time," study author Elizabeth Austic, a postdoctoral fellow at the university's Injury Center, said in a university news release.
"To prevent someone from using for the first time is often more cost-efficient and effective than trying to intervene once they have done it, whether a few times or for years," she said.
The researchers analyzed data from more than 240,000 people ages 12 to 21. They found the peak ages for using these drugs without a prescription -- in order to get high, lose weight or for other reasons -- are between 16 and 19.
Each year, just under 1 percent of teens ages 16-19 start using stimulant medications not prescribed to them, the study determined. Besides Ritalin, Adderall and other ADHD medications, these include prescription diet drugs and medicines that contain methamphetamine.
Prescription diet pills were the most popular stimulant drug misused by females, while Adderall was the drug misused most often by males, according to the study.
Noting that college students are thought to take stimulant drugs to cram for exams, Austic said, "People have been thinking this is a college problem, but they just don't realize how prevalent it is at younger ages."