Like vision and hearing tests, drug testing can alert parents to potential problems that continued drug use might cause, such as liver or lung damage, memory impairment, addiction, overdose, even death.
 

Testing can also be an effective way to prevent drug use. The expectation that they may be randomly tested is enough to make some students stop using drugs—or never start in the first place.
 

That kind of deterrence has been demonstrated many times over in the American workplace. Employees in many national security and safety-sensitive positions—airline pilots, commercial truck drivers, school bus drivers, to name a few—are subject to pre-employment and random drug tests to ensure public safety. Employers who have followed the Federal model have seen a 67- percent drop in positive drug tests. Along with significant declines in absenteeism, accidents, and healthcare costs, they’ve also experienced dramatic increases in worker productivity. 
 

In numerous countries practising the tests of drugs, a number students resist the idea of drug testing, many endorse it. For one thing, it gives them a good excuse to say “no” to drugs. Peer pressure among young people can be a powerful and persuasive force. Knowing they may have to submit to a drug test can help kids overcome the pressure to take drugs by giving them a convenient "out".
 

It is important to understand that the goal of school-based drug testing is not to punish students who use drugs. The primary purpose is to deter use and guide those who test positive into counseling or treatment. In addition, drug testing in schools should never be undertaken as a stand-alone response to the drug problem. Rather, it should be one component of a broader program designed to reduce students’ use of illegal drugs.