The setting is usually an abandoned parking lot, or a quiet park, or the basement of somebody's house. Teens laugh nervously as a friend writhes on the ground in loose-limbed confusion, disoriented and gripped by powerful hallucinations.
The source of the delirium is an herb called salvia divinorum, which is legal in most of the United States. It can be bought online or in stores as dried leaves or extract. Salvia is not banned by the federal government, but its growing use has attracted the attention of as many as nine states that have voted to make it illegal, and legislators in several other states are considering restrictions.
At the same time, researchers are just beginning to understand how the drug affects the brain, and are finding that its psychoactive ingredient works differently than other hallucinogens, such as LSD.
Known as Magic Mint, Sally D, or Diviner's Sage, salvia is a fast-acting natural hallucinogen that causes an intense 15- to 30-minute high.
A member of the mint family, salvia's origins trace back to the Mazatec Indians of northern Oaxaca, Mexico. They either chewed the herb or mixed it with water to induce visions for shamanic rituals.
"It was similar to how Native Americans use Peyote," said Dr. Jonathan Appel, chair of the department of behavioral and social sciences at Tiffin University and a former drug abuse counselor. "Shamans would enter the spiritual world and do diagnoses from the spiritual world."
In the many YouTube and Myspace videos documenting teenage salvia use, the herb is often smoked in a pipe or a water bong, which users say triggers a powerful high. In one video, a boy blows out smoke, stumbles across a lawn and then falls over backward, as his friends laugh. In another, a girl announces she can no longer feel her mouth and in another, a teen in a hooded sweatshirt stares at his bong and then screams, again and again, wordlessly.
Users report visual distortions, loss of balance and motor control. The high is quicker and more intense than other hallucinogens, causing many users to lose contact with their surroundings.
"The phrase often used is you're catapulted out of time and space," Appel said. "You're shot out of a cannon in your mind."
Florida State Rep. Mary Brandenburg has authored a bill to make sale or possession of salvia illegal in the state of Florida and punishable by up to five years in prison. The bill passed the Florida legislature and is awaiting signature by the governor, which would make it one of as many as nine states to ban the herb.
"I was concerned first of all about the potential for physical harm that the use of salvia has," Brandenburg said. "I'm also concerned about the use of salvia as a gateway drug to get into other hallucinogenic drugs. It's legal, and relatively easy to get."
After failing to get a similar bill passed in 2007 in California, Republican Assemblyman Anthony Adams of Hesperia recently introduced a bill to ban the sale of salvia to minors in the state.
"You don't have to look any further than the screens of YouTube to see people using this drug as a recreational device," Adams said. "It's absolutely conceivable that someone on salvia could harm themselves or worse, others, while using the drug."
But John Mendelson, a senior scientist at the California Pacific Medical Center Research Institute, thinks that designating salvia as a Schedule 1 substance is going too far.
"You take a 20-year-old, convict them of a Schedule 1 felony and put them in jail, and you damn well know what their lives are going to be like," Mendelson said. "They're finished. They can't hold a federal job. There's a real consequence to that."
Salvinorin A, the psychoactive molecule in salvia divinorum, is structurally distinct from other hallucinogens, such as LSD or mescaline. Research shows that the molecule has no affinity for the serotonin receptor, a key player in other hallucinogenic drugs.
Instead, Salvinorin A interacts with the brain's kappa-opioid receptors, cell proteins that bind to specific molecules. When the salvinorin A molecule binds to these receptors, it triggers a cellular response that can be felt throughout the body almost immediately.
It is that interaction between the herb's molecules and the brain that Jacob Hooker, a research fellow at the U.S. Department of Energy's Brookhaven National Laboratory, has been studying.
Using positron emission tomography scans on lab animals, Hooker's team found that within seconds, a high concentration of the drug localizes in the visual cortex and the cerebellum of the brain, areas responsible for vision and motor control, respectively. The drug then clears from the brain just a few minutes later. Previous research has shown that is also highly selective, meaning it quickly targets and grabs onto the kappa-opioid receptors.
"It is incredibly interesting not only for its selectivity and affinity for this receptor, but also its rapid onset and short duration," Hooker said of salvinorin A. "It's unusual to find a drug with such high affinity for a given receptor that has incredibly short-lasting acute effects."
More research is needed to determine whether salvia could provide clues for new treatments, possibly for bipolar illness, Mendelson said.
"In some animal studies, kappa agonists have decreased animal behaviors consistent with mania," he said, adding, "I don't think Salvinorin A is going to be a treatment for anyone. It has distorting effects, and it's unpleasant for some people."
Drugs that are chemically similar, however, could have potential treatment uses, he said. It is this possible benefit that worries him as more states consider designating salvia as a Schedule 1 agent. Should it be legally lumped in with LSD or other hallucinogens, researchers would be severely limited in the work they could do.
In what he hopes will lead to a "smarter, more nuanced" approach, Mendelson has been conducting trials to determine the dose levels that cause hallucination in humans.
"We need to know how many people are using this drug, how much is being sold, what doses are psychoactive and what the medical and psychiatric consequences are," he said. "We desperately need that information."