Meth 'hijacks' brain, expert says (Indiana)

By Joe Gerrety
jgerrety@journalandcourier.com

March 9, 2006

Methamphetamine addicts act like no other type of drug addicts George Frantz has encountered in more than 20 years as a drug investigator in western Indiana.

And after hearing a pharmacology professor's explanation Wednesday of how meth works on the brain, Frantz has a better understanding of why.

"The meth addict is just a totally different person than what I've dealt with," said Frantz, of the Bi-State Drug Task Force. "They're totally consumed."

That's because methamphetamine "hijacks the normal reward pathways of the brain," according to Eric Barker, associate professor of medicinal chemistry and molecular pharmacology at Purdue University.

Barker addressed a crowd of more than 70 people at the third of four monthly forums on methamphetamine sponsored by the Mental Health Association.

"The drug itself can be completely satisfying because it has hijacked that pathway," Barker said.

As a result, meth addicts can go days without food or sleep and sometimes are unfazed when child services workers take custody of their children.

People who aren't addicted to drugs gain pleasure from things such as food, water, sex and nurturing, Barker said. The rewarding feeling people gain from eating and other pleasurable activities comes from the release in the brain of a chemical called dopamine.

In a normally functioning brain, Barker said, dopamine is released into the synapses between brain cells. Once the pleasurable feeling is achieved, "uptake pumps" reabsorb the unused dopamine.

But methamphetamine acts to block those uptake pumps and causes them to act in reverse, causing "a massive elevation of dopamine." That, in turn, affects the nearby judgment pathways of the brain, causing the abuser to neglect other needs in his pursuit of more meth.

"I have to agree 100 percent with what he said," Frantz, the drug investigator, said.

Long-term meth users he has encountered are not only obsessed with the drug, they frequently are paranoid. One recovering meth abuser in a neighboring county recently told Frantz that, at the height of his addiction, he was convinced Frantz was watching him 24 hours a day.

Frantz said some self-taught meth cookers become obsessed with the process of manufacturing the drug from items such as cold products, lithium batteries and anhydrous ammonia.

A meth maker once told Frantz, "I have to make meth everyday, and I have to produce a better batch today than I did yesterday."

The good news, Barker said, is that there has been some success in treating methamphetamine addiction. One approach called the Matrix Model, a 16-week intervention program, managed to reduce meth use among those who completed the program by 50 percent in the first six months after treatment.

That success rate is comparable with treatment programs for other chronic illnesses such as diabetes, asthma and hypertension, Barker said.

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