Poison control centers in the U.S. began tracking use of the drugs in 2010. The majority of the early reports of drug use were clustered in Southern states like Louisiana, Tennessee and Kentucky. But the problem soon spread across the country.
The financial lure for small-time drugmakers is enticing. The drugs can be cheaply imported from China or India, and then easily packaged under local brands. For example, bath salts sold in Louisiana carry regional names like Hurricane Charlie or Bayou.
The widespread availability of the drugs in stores is equally alluring for drug users: they can get a cheap high similar to that of illegal drugs by walking to a corner store.
The most dangerous synthetic drugs are stimulants that affect levels of both dopamine and serotonin, brain chemicals that affect mood and perception. Users, who typically smoke or snort the powder-based drugs, may experience a surge in energy, fever and delusions of invincibility.
Use of these drugs has spread across the country with reports stretching from Maine to California. There are no official federal estimates on deaths connected with the drugs, many of which do not show up on typical drug tests. But police reports have implicated the drugs in several cases.
Packets of "Lady Bubbles" bath salts, for instance, were found on Sgt. David Franklyn Stewart last April after the solider shot and killed his wife and himself during a car chase with law enforcement near Olympia, Wash.
The chase began when Stewart sped past a police patrol car at 6 a.m. The police trooper pursued for 10 miles and reported seeing the driver raise a hand to his head, then heard a shot and saw the driver slump over. The next day police found the couple's 5-year-old son dead in their home; he had been suffocated with a plastic bag at least 24 hours earlier.
Another death involving bath salts played out in Covington, La. Police reported that Dickie Sanders, 21, shot himself in the head Nov. 11, 2010 while his parents were asleep.
His father, Dr. Richard Sanders, said his son had snorted "Cloud 9" bath salts and endured three days of intermittent delirium, at one point attempting to cut his own throat. As he continued to have visions, his physician father tried to calm him. But the elder Sanders said that as he slept, his son went into another room and shot himself.
Hospital emergency rooms, doctors and law enforcement agencies across the country have struggled to control bath salt drug users who often are feverish and paranoid that they are being attacked. Doctors say users often turn up naked because bath salts raise their body temperature so much that they strip off their clothing.
Cookeville Regional Medical Center in Tennessee has treated 160 people suspected of taking bath salts since 2010. Dr. Sullivan Smith, who works there, said people on the drugs become combative, and it can take four or five health professionals to subdue them. In some cases, he said, doctors have to use prescription sedatives that are typically reserved for surgery.
Smith recalls one man who had been running for more than 24 hours because he believed the devil was chasing him with an ax. By the time police brought him to the hospital, he was dehydrated and covered in blood from running through thorny underbrush.
"We're seeing extreme agitation, hallucinations that are very vivid, paranoia and some really violent behavior, so it's a real crisis for us," Smith said. "We sedate the living daylights out of them. And we're talking doses on the order of 10 or 20 times what you would give for a painful procedure."
To control the spread of the problem, the Drug Enforcement Agency issued a temporary ban in October on three of the most common drugs — mephedrone, methylone and MDPV. That ban became permanent under the bill signed by Obama on July 10.
Under the law, anyone convicted of selling, making or possessing 28 synthetic drugs, including bath salts, will face penalties similar to those for dealing traditional drugs like cocaine and heroin.