Approximately one in five U.S. schools has instituted mandatory student drug testing programs, but research suggests that these programs are not effective at reducing teenage drug abuse. Furthermore, regular testing of a reasonably-sized group of students can be expensive, and many critics feel that it is not a good use of limited school funding. The majority of schools with mandatory drug testing programs test students who choose to participate in athletics or other extracurricular activities. A case questioning the legality of drug testing these students reached the U.S. Supreme Court in 2002, but the testing was ruled to be legal in a narrow 5-4 decision. However, a nationally representative survey of such schools found that 28 percent of them have chosen to randomly test all of their students, not just those who join school sports teams or clubs. These schools may find themselves vulnerable to future legal challenges, given that the Supreme Court ruling referred specifically to the testing of students who participated in after-school programs. Studies Suggest Testing Doesn\u2019t Impact Teen Drug Use Supporters of these drug testing programs argue that the invasion of privacy that the testing involves is justified by the need to reduce teenage experimentation with dangerous, illegal drugs. However, several studies in recent years have questioned the efficacy of these programs, concluding that they are not reducing drug use among the high school students in participating schools. A 2013 study published in the Journal of Adolescent Health found that student drug testing was associated with moderately lower marijuana use but higher use of other illegal drugs. A 2013 report prepared for the Institute of Education Sciences found that while student drug testing had a short-term impact on drug use among students who were actually tested, it did not deter students who were not tested and had no long-term impact on either tested or non-tested students. Finally, a 2014 study published in the Journal of Studies on Alcohol and Drugs found that perceived student drug testing did not reduce student substance use but that changes to improve school climate were associated with reduced smoking and marijuana use (although not reduced drinking). Critics Question Lack of Focus on Alcohol Abuse Opponents of student drug testing have also criticized the fact that schools do not test for alcohol, which is by far the most commonly used psychoactive substance among teenagers. As a result of its widespread use, alcohol is also the most dangerous drug for teenagers, threatening student health, safety, social experience and academic performance. One of the most influential voices to oppose student drug testing is the American Academy of Pediatrics (AAP). The AAP cites the current lack of evidence supporting the efficacy of these programs in a report released in the April 2015 edition of Pediatrics. Cost is also a concern with student drug testing. The AAP estimates the cost of a single drug test at $24, and because schools must usually test many students in order to get a single positive result, the average cost of one positive drug test comes in at around $3,000. Many schools will spend significantly more than that, depending on the number of students they plan to test each year. Even if many schools find alternate sources of funding such as grants or private donors to pay for the drug testing, it is still a lot of money to spend on programs that are not making an impact.