Random drug tests for student-athletes may not just disclose illegal drug use; they may also discourage it. That's the conclusion of a National Institutes of HealthÐfunded study, which found that student-athletes subjected to random tests were almost four times less likely to use illegal drugs than untested student-athletes.

This month's Journal of Adolescent Health reports on the study, which tracked drug use among athletes (based on reports in confidential surveys) at two demographically similar Oregon high schools. At the school with drug tests, 5.3 percent of the school's athletes reported using illegal drugs during the one-year study period. At the school without drug tests, 19.4 percent of the athletes said they used illegal drugs. Rates of drug use among non-athletes (who were not tested) at the two schools were similar.

The U.S. Supreme Court ruled last June that public schools can require students involved in extracurricular activities to undergo drug tests.