LAKEWOOD RANCH -- When Jan Froelich noticed her 16-year-old son's anxiety and mood swings were getting worse around Christmas, she knew she couldn't attribute them just to adolescence.

And when he complained of a rapid heart beat, she got to bottom of the problem: He was smoking synthetic marijuana.

"I didn't know this stuff was out there," said Froelich, a registered nurse and the director of cardiovascular services at Lakewood Ranch Medical Center.

Synthetic marijuana is sold over-the-counter at many convenience stores and gas stations as an herbal incense with such names as K2, Serenity

Now, Herbal Spice, Red Magic, Black Mamba and Mr. Sticky.

Although the packages have "Not for Human Consumption" printed on them, people, many of them teenagers, are smoking it.

Smoking the herbal incense affects individuals differently, but it tends to enhance anxiety or even cause psychosis, according to Dr. Steven Watsky, an emergency room physician at Lakewood Ranch Medical Center and Manatee Memorial Hospital.

"Some people are prone to nervousness and psychosis," Watsky said. "The drug brings it out."

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