August 28, 2008 -- One of the men investigated for allegedly threatening presidential candidate Barack Obama's life while on a methamphetamine binge, is scheduled to appear in federal court this afternoon on a charge of possessing the narcotic.

Tharin Robert Gartrell is currently in custody, along with two other men who face meth-related and illegal possession of firearms charges.

The arrest of the three men has focused renewed attention on the paranoia and psychosis that go along with abuse of the drug which is widely used across the country.

Medical experts say their supposed admissions about an assassination plot fit into the expected pattern of erratic behavior from meth users.

Gartrell, Shawn Robert Adolf, and Nathan Johnson expressed strongly racist views and spoke about killing the Democratic presidential nominee while using meth, according to U.S. Atty. Troy Eid. The talk, Eid said, does not meet the legal standard for filing charges for threatening a presidential candidate.

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Doctors who study the effects of meth on the brain say the men would not likely have been able to carry out their alleged threats because meth make its user virtually incapable of completing any task besides getting more of the drug.

"There's no way they could have gotten their act together to do anything because they are so paranoid, their thinking is so altered that they start things and they can't finish them," said Dr. Richard Rawson, a professor at the UCLA School of Medicine who specializes in the study of methamphetamines and their affect on the brain.

"But," he said, "It is scary to have the words methamphetamine, guns, and Democratic National Convention all in the same sentence."

Rawson said the scales have tipped to where "hard core" addicts are using more and more meth while the number of new users is declining.

"There is this corps of more severely addicted people and they're not the dabblers. They're heavy users and they get more meth psychosis, paranoia, and judgment impairment," said Rawson. "It's more like heroin addiction."

Part of the reason for this trend stems from recent laws that restrict the amount of pseudo-ephedrine, a key ingredient in meth manufacturing, that an individual can purchase at one time.

The effect has been that it is more difficult for people to get the ingredients to make meth at home or in their vehicles: "We've seen a decline in homemade meth because of this law."

A mobile methamphetamine lab was found in the vehicle of one of the men arrested. Rawson said that some highly addicted people will get around the new laws by doing something they called "smurfing," where they go from one drug store to another and buy the maximum legal amount of pseudo-ephedrine off the shelf in order to have enough of the ingredient to "cook" the drug.

Though the new laws have helped to reduce the number of new meth users, they don't necessarily translate into a smaller quantity of the drug overall in the United States.

Rawson says that Mexican cartels have moved in to supply the meth markets that are already well established.

The result, he said, is higher priced meth that is more potent and more addictive.

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