Locally, the meth problem is worse. There were more admissions directly related to meth in Oregon than in any other state tracking the data. And while alcohol is responsible for the most admissions at the Portland VAMC, patients admitted with meth addiction are often more psychiatrically ill than patients addicted to other drugs.
A key difference between cocaine and meth that might account for meth's more addictive characteristics is that while cocaine and meth both block the recycling of dopamine at the nerve terminal, meth also prevents the second step of recycling inside the terminal where dopamine is repackaged and ready for release again.
"You get a dump of dopamine into the synapse, the space between the nerve cells," Janowsky said. "Meth is taken up by the transporter, causing release of more of the neurotransmitter, but cocaine only blocks the re-uptake of the neurotransmitter."
The center contains four research themes to study the effects of meth use. One will focus on the areas and systems of the brain involved in drug craving and drug effects. Another will examine the changes in gene, nerve cell and brain function that accompany meth exposure and withdrawal. A third theme will look at the effects of stress on drug craving and the potential for relapse. The fourth will study impulsivity and the decision-making process associated with meth use.
Several pilot projects already are in progress at the MARC. One involves using functional magnetic resonance imaging, or fMRI, to examine the brains of former meth users while they take a test that measures t
Contact: Jonathan Modie
Oregon Health & Science University