At first, the soldier's behavior was puzzling. He appeared to be having hallucinations. He was anxious. He became belligerent.
A drug test identified the problem: The young man had become the latest service member at Fort Meade to experience an adverse reaction to synthetic marijuana.
Commanders at the Army base in Anne Arundel County, home to the National Security Agency, the U.S. Cyber Command and other sensitive activities, are cracking down on cheap, widely available and dangerous marijuana substitutes that have been linked nationally to suicides and homicides.
Soldiers have been barred since 2011 from using synthetic marijuana, and the Drug Enforcement Agency last year banned many of the chemicals that can be used to make it.
But the regulations have not stopped its use by military members or the general population.
"It has turned up a little bit more" in recent years, said Col. Edward C. Rothstein, garrison commander at Fort Meade. "And that's because a better spotlight has been put on the problem."
Rothstein said 15 service members at Fort Meade tested positive for synthetic marijuana last year, up from five the year before.
But those numbers likely represent only a fraction of the actual use, because soldiers are not routinely tested for the drug. The tests that produced the positives were ordered only after commanders suspected that a soldier was using drugs.
Rothstein recently declared two service stations off-limits to service members assigned to Fort Meade. He says the businesses have sold a product called "Spice," one of the names by which synthetic marijuana is marketed. Service members who enter either establishment may be punished under military law.
But he says his focus is on the health and welfare of the individual service members, and the force as a whole.
"We look holistically at the soldier," he said, "and how is that tied to, then, their readiness."
The efforts at Fort Meade reflect larger campaigns by the Army and the other service branches to address the use of designer drugs.
Marketed deceptively as a "legal high," synthetic marijuana is made from leaves that are coated with chemicals that supposedly mimic the effects of marijuana but can be more powerful and longer-lasting.
"They take this solution, they spray it on top of a potpourri type of ingredient, no quality control, they package it up, and then you may get more of a concentration on your end of the package than another person that may not have got any sprayed on it," said Buddy Horne, drug testing manager for the Army Substance Abuse Program, based at Fort Knox, Ky.
"So this is a very dangerous combination that soldiers are experimenting with. When they do use it ... the episodes in poison control centers have increased."
Physicians at the Naval Medical Center San Diego published a case study in the American Psychiatry Journal of 10 synthetic marijuana users admitted to the hospital during a five-month period in 2010.
Drs. Donald Hurst, George Loeffler and Robert McLay described the patients as otherwise healthy men, ages 21 to 25, who reported usage ranging from a few times to daily.
Nine of the patients had paranoid delusions, four had auditory hallucinations and two had visual hallucinations, the doctors reported. Seven had disorganized speech, six had disorganized behavior and four had thoughts of suicide.
Seven of the patients saw their psychotic symptoms resolve five to eight days after they were admitted. Three patients continued to suffer psychotic symptoms more than five months later.
Les McFarling, director of the Army Substance Abuse Program, said it's difficult to know how widespread the use of synthetic marijuana is.
"We've seen some limited usage," he said. "Without having a specific test that's part of our urinalysis panel — which this Spice cannot be — it's difficult to gauge the extent of use as compared to something like cocaine or THC, which we've been able to measure for years and years."
Still, he said, the Army is taking the drug "very, very seriously."
"Some of the more concerning effects are, No. 1, the 'high' doesn't go away," he said. "The effects can range from extreme euphoria, you know you're breaking down and crying and thanking the world that you're here, to absolute paranoid schizophrenia. It raises people's body temperatures. They want to start taking their clothes off. ...
"But the bottom line is, if you want to play Russian roulette with your mind and your body, then go ahead and step up and try Spice. Because you don't know what you're going to get, but it could affect you for the rest of your life."
Among the challenges to military commanders has been the ready availability of synthetic marijuana in the communities in which service members are based. Because it can be made from a variety of chemicals, manufacturers have been able to change the ingredients to stay ahead of regulators.
Rothstein, the Fort Meade commander, raised the issue of synthetic marijuana use last year at a meeting of military commanders and state government leaders.
He described it as a "distracter," and said he would be working local officials and community leaders "to see what we can do to try to make it at least harder for these young service members to get this."
He said he learned of the drug from a friend on the base whose son had used it.
"It's been here for a while. When I say here in the community, yes on Fort Meade, but also outside the fence line. ... It's not by any means an epidemic. Nor do I believe that this community is an epicenter for this problem."
Rothstein said he asked military police investigators to determine how easily service members could obtain the drug. He added the two service stations to Fort Meade's off-limits list last month.
"The intent absolutely is not a witch-hunt approach," he said. "I truly believe that at the end of the day, it's a community approach. And it's the entire community, not to single out businesses or institutions, but to ensure that we all work together to eradicate this problem."