The number of workers and job candidates testing positive for use of opiates and prescription drugs with opiates fell significantly over the past year, according to the latest data from Diagnostic Laboratory Services Inc., the state’s largest locally owned drug testing company.

Diagnostic’s third quarter test results show the number of people using either legal or illegal opiate drugs fell to under 0.25 percent from more than 0.5 percent a year ago.
Carl Linden, Diagnostic Laboratories scientific director, said he was unsure why opiate usage had declined over the past year, but that it followed a increase in usage of opiates over the past several years.
Other test results for marijuana, amphetamine and cocaine remained relatively unchanged compared to a year earlier. The laboratory tests between 5,000 and 10,000 people each quarter, most of which are job candidates.