One in ten teens says they use"study drugs"to improve their performance in school. So-called "study drugs"refer to prescription medicines  that are used to treat ADHD .But most parents have no understanding of the problem, a new study finds. In January, 2013, researchers from the University of Michigan Mott Children's Hospital did a national survey of more than seven hundred families with teens. They found that only one percent of parents believe their child has taken a study drug. Yet in a 2012 University of Michigan study, ten percent of second-year high school students and twelve percent of third-year high school students say they use a study drug. The misuse of study drugs didn't come to the attention of almost all parents."What we found in this survey is a clear mismatch ,"said Dr. Matthew Davis, one of the researchers. It is a mismatch between what parents believed and what their kids were reporting. "We know teens are spreading the word that these drugs can improve their grades,"Davis said."But these prescription medicines are drugs. And teens who use them without a prescription are taking a serious risk." The new survey showed that fifty-four percent of white parents were"very concerned"about their child taking study drugs, compared with thirty-eight percent of Hispanic  parents and thirty-seven percent of black parents. However, just twenty-seven percent of parents surveyed have talked to their teens about using study drugs. Of these parents, forty-one percent were black, twenty-seven percent were white and seventeen percent were Hispanic. Students with a prescription for an ADHD drug should be required to keep their medicines in a safe place, such as the school nurse's office. Seventy-nine percent of parents think so, the survey shows. This may help prevent _ from being shared or used by other students. What is the purpose of this text?
To give useful advice. To introduce a new drug. To report a research result To explain what ADHD is.