Efforts to educate members of the U.S. military about the dangers of synthetic drugs, coupled with improved drug testing, are starting to have an effect, the Navy Times reports. The Navy and Marine Corps report a drop in members using Spice and bath salts.

The Defense Department first began responding to use of synthetic drugs in the military in 2010, the article notes. The department banned the compounds, and began to develop tests for them. In 2012, the military started an awareness campaign about synthetic drugs.

In the past year, the Navy and Marine Corps report a 45 percent in the monthly average of members who were found using Spice (synthetic marijuana) and a 60 percent decrease in those found to be using bath salts.

Keeping up with ever-changing formulations of synthetic drugs is difficult, according to Terrence Boos, a chemist with the Drug Enforcement Administration. “The evolution of these drugs is providing a challenge for toxicology screens,” he said. “When someone is presenting at an emergency department, they are presenting with an unknown drug in their system.”