Types of Drug Tests and Their Accuracy

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Lab bottles

In one of our latest posts, we discussed the pros and cons to drug testing a loved one. There is no right or wrong answer – you must decide what is best for you and your family. In some cases, drug testing is a good idea, as it gives the recovering addict accountability and provides reassurance to the family.

However, before you jump into buying a drug test, it’s important to know that they are not always reliable. Not only can your loved one alter the results, but also the test could give you a false positive or false negative.

Types of Drug Tests

There are five main types of drug tests. Let’s explore.

  • Urine. Urine tests are common and used by employers and law enforcement because they are cheap, easy and noninvasive. You can buy an at-home kit for your loved one for under $50. Unfortunately, these tests are not always accurate.

  • Saliva. Saliva tests are becoming more common because they, too, are noninvasive and easy to administer. Saliva tests are generally only useful for detecting recent drug use, and there are no nationally accepted standards for detection. This means that drug use could show up on one test and not another.

  • Hair. Hair drug tests are best for detecting drug use from a longer time ago, usually up to 4 months. About an inch-and-a-half of hair is needed for the test to be completed, and a wide range of substances can be checked for. The test is more expensive than others, sometimes costing up to $150. Also, minorities or those who were exposed to marijuana smoke are more likely to get a false positive.

  • Blood. Blood tests are expensive and invasive. They are rarely used to test for drug use, though they are the most accurate and may be used to confirm the presence of drugs.

  • Sweat. In a sweat drug test, a patch is worn on the skin to check for drugs in the body. However, these tests are highly questionable since the results can be contaminated from the skin’s surface.

How People Cheat Drug Tests

If you do decide to drug test your loved one at home, please be aware of the possibility of false negatives and false positives. In the case of urine testing, here are some of the ways that the sample may be tampered.

  • Diluting the urine by drinking large amounts of water beforehand

  • Substituting urine from another friend or family member

  • Adding commercial cleaners to the urine

  • Drinking vinegar to adjust the pH balance of the urine

  • Adding substances such as salt, soap or eye drops to the urine

You must keep in mind that drug tests are not 100% accurate. If you do decide to test, follow up any positive results with a lab test to know for certain. And, always remember that you should only drug test a loved one if it’s in their best interest and helping their recovery, not hurting it.