pill bottleThis just in…according to The Wall Street Journal, Quest Diagnostics released an analysis relating to millions of drug tests and it turns out the bulk of U.S. workers who tested positive for drugs has declined significantly the past 25 years.

Apparently cocaine and marijuana use have dropped considerably but researchers aren’t exactly jumping for joy. That is, data points to the growing abuse of prescription drugs.

After looking at more than 125 million urine drug test results from 1988 through 2012 (sounds gross, doesn’t it?), 3.5 percent of the samples from last year came back positive compared to 13.6 percent in 1988. While most of the tests were conducted as measures for pre-employment, the remainder were conducted after accidents, part of regular testing time periods or after employers suspected their employees were using drugs.

In their findings, Quest also discovered that amphetamines more than doubled the past 10 years. This includes Adderall, a prescription drug. Tests for painkillers like Vicodin and OxyContin skyrocketed, too. They catapulted by 172 and 71 percent, respectively the past seven years.

This is cause for concern for employers. Even though they’ve been prescribed, the abovementioned drugs can have an impact on safety at work.