Drug testing first became popular with the professional sports, football, baseball etc... How ever the labs couldn't make enough money to stay in business. Then came along the diseased organisum we call the federal government and the war on drugs. This allowed major labs to stay in business, hense the preemployment drug testing industry we have today. Drug testing is now a multibillion dollar industry which created it's self. There are no studies showing that drug testing reduces drug use, NONE. In all accuality drug testing has done little to reduce use at all. In fact, once people knew that THC was the most likely drug to show positive on a screen, people just switched over to other drugs with a much shorter half life, to avoid detection. So there you have it, the drug war has done nothing but promote even harder drugs being used as these drug's leave the system quickly so as to avoid detection. As far as AAS are concerned, no they don't test for them as the use is wide spead and is not perceived politically as beneficial to the "cause", and they are expensive to test for anyway. So much for our political system improving life here in "Amerika".