UF study: Many meth side effects kick in only after stopping
Published: Tuesday, February 19, 2013 at 5:24 p.m.
Last Modified: Tuesday, February 19, 2013 at 5:24 p.m.
Some of the negative side effects of taking methamphetamines begin only after users have stopped taking them, according to a recent study by University of Florida researchers.
A study led by Dr. Habibeh Khoshbouei, an associate professor of neuroscience and psychiatry at the UF College of Medicine, showed that mice withdrawing from methamphetamines had memory loss and a decrease in neuronal activity two weeks after the withdrawal began -- the equivalent of one year in humans. The mice did not have the same symptoms while they were still taking the drugs.
“It is very well established that people who abuse meth show symptoms of neurodegeneration and psychosis, so long-term meth abuse can produce all sorts of problems,” Khoshbouei said.
Meth induces an uncontrolled release of dopamine, a neurotransmitter responsible for pleasure.
“It exposes the brain to too much dopamine, which feels good at the time but has both immediate and long-term consequences — namely of killing neurons,” said Dr. Jamie Smolen, an addiction psychiatrist at UF.
Smolen added that the long-term use of meth might change receptors in the brain permanently, impairing memory, attention span and what is called “executive function,” or the ability to take in information, process it and make decisions based on it.
For example, people who had used meth might have difficulty balancing their checkbook, preparing a meal or buying groceries, Smolen said. Certainly, holding down a job and driving a car would be almost impossible.
“The longer a person is abusing a drug, the more toxicity occurs in the nervous system and the harder it is for the system to repair itself,” Smolen said.
Although all drugs cause some damage to the body, meth is particularly hard on the central nervous system, and in another study of users of various drugs including cocaine, only the meth users had symptoms similar to those of Parkinson's disease patients, Khoshbouei said.
In her recent study, which was published in the journal Synapse, the mice also showed a decreased volume in their hippocampus, the brain's center of learning and memory that also is impaired in Parkinson's disease patients.
Meth use also can cause severe acne, teeth loss and weight loss, Smolen said.
“It's a very destructive drug in the physical form of the body,” he said.
Smolen said various drugs can help addicts withdraw from meth, including the anti-depressants fluoxetine, buproprion and imipramine, the sleep apnea drug modafinil, and the bipolar/schizophrenia drug Abilify.
These drugs provide some of meth's desired effects without being addictive, Smolen said, adding, “Obviously the other treatment is the traditional residential treatment … staying in a program where you live in a therapeutic environment. That is a component that can't be dispensed with.”
Khoshbouei cautioned that pharmacotherapies might not be able to reverse the biochemical changes brought on by meth use, though. “The long-term consequences are not known, but the glimpses are not good,” she said.
Although “meth labs” have been reported to exist in abundance throughout Florida, Georgia and Tennessee, Smolen said he has had only one patient with a meth addiction in several years and that he suspects much of the addiction problem is in the Midwest.
Still, Khoshbouei warns that the scope of the problem is big, citing that in 2005, 200 billion doses of meth were distributed in the U.S. It's also cheap and easy to make, which makes it an attractive drug for young people.
“When I see kids abuse any drugs, I'm thinking, ‘Am I doing enough to warn them?'” Khoshbouei said. “Because I know that it's going to have effects that are irreversible.”
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