Parents also tended to under-report their teenagers' substance abuse, leading the researchers to conclude that health-care providers should rely on other methods, such as drug testing, rather than self-reports or parents' reports to identify at-risk teens.
Previous studies looking into teens' truthfulness about their drug use appear to have looked only at kids in drug treatment or in the court system, Delaney-Black said.
Ty S. Schepis, an assistant professor of psychology at Texas State University at San Marcos, said the study "generally reinforces what we know from work in adults, which is that people are usually less honest about substance use than we hope."
People are reluctant to tell researchers, or almost anyone for that matter, that they participate in illegal or undesirable activities, he said.
"Even if it means lying, people often like to present themselves in a favorable light," he added.
The U.S. National Library of Medicine has more on teens and drug use.
SOURCES: Virginia Delaney-Black, M.D., M.P.H., professor of pediatrics, Children's Hospital of Michigan, Detroit; Ty S. Schepis, Ph.D., assistant professor, department of psychology, Texas State University, San Marcos; Oct. 25, 2010, Pediatrics, online
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