I believe testing your teen for drugs is a personal decision and should be based on your family dynamics, your relationship with your teen and your level of suspicion. Keep in mind that you cannot physically force your teen to give you a sample. Generally, a teen that refuses to take the test knows they are guilty, but this is not the case with every teen. Some teens will gladly take the test just to prove you wrong. Below are some common questions and answers regarding home drug tests.
Most tests use a urine, saliva or hair sample.
The test is based on a chemical reaction from the sample, similar to how home pregnancy tests work. If the chemicals detect drugs, a certain reaction will be noted on the test. Marijuana, cocaine, ecstasy, speed, heroin and other drugs, including those that fall into the barbiturate category. Ritalin has also been shown to cause a false positive under this category of drug. Certain pain medications, whether they are name brand or generics containing Codeine, can produce false positive results for the use of heroin or morphine, which fall under the opiate category.