APA Dictionary of Psychology

a test to determine whether legal or illegal substances are present in a person’s body. Depending on the type of test conducted, blood, urine, saliva, hair, sweat, vomit, or stomach contents can be analyzed. Toxicology screens may be conducted on professional athletes or employees for evidence of illegal substance use; by forensic investigators attempting to determine the cause of a person’s death; or for patients suspected of drug overdose or some toxicity, among other applications. The results of the test may not be entirely precise, depending on the substance and the quantity ingested, the time elapsed since it was taken, other substances in the person’s system, and the person’s metabolism. Follow-up screens are thus usually warranted to confirm positive results.