A new study by research and diagnostic testing firm Quest Diagnostics has revealed a disturbing trend: More employees are testing positive for drugs in their system.

But first, the good news: The rate in 2017 of drug positivity results - where Quest looked at more than ten million lab tests - was mostly the same as a similar study the company conducted in 2016. Also, prescription opiate positivity rates declined "dramatically" on a national basis.

Unfortunately, the good news stops there. That's because the study showed a dramatic increase of other drugs found in the blood and urine of subjects and this led to an overall positivity rate of 4.2 percent of employees, which is the highest since the 3.6 percent rate recorded in 2008. The top rate ever recorded was 13.6 percent in 1988, the first year of the study. The lowest rate ever recorded by the study was 3.5 percent in 2012.

"It's unfortunate that we mark 30 years of the Drug-Free Workplace Act with clear evidence that drugs continue to invade the country's workplaces," a researcher from the company noted. "These changing patterns and geographical variations may challenge the ability of employers to anticipate the "drug of choice" for their workforce or where to best focus their drug prevention efforts to ensure a safe and healthy work environment."

The study suggests that more people are using cocaine in some areas of the country, with rates of use rising significantly for the fifth year. Double-digit year-over-year increases in at least four of the five past years were seen in the states of Nebraska (91 percent increase between 2016 and 2017), Idaho (88 percent increase), Washington (31 percent), Nevada (25 percent), Maryland (22 percent increase), and Wisconsin (13 percent). There were also large increases of methamphetamine use across the country.

Not surprisingly, states that have legalized marijuana for recreational use have also seen increases in positivity rates of up to 43 percent. But more of a concern is that certain states (Nevada, Massachusetts and California) have seen significant increases in marijuana positivity in federally mandated, safety sensitive workers, which include pilots, rail, bus and truck drivers, and workers in nuclear power plants.