Tuesday, May 27, 2014

fMRI Reveals Brain Changes in Meth Users That May Influence Risk-Taking, Poor Decision-Making


Risk-taking and poor decision-making by methamphetamine users may reflect dysfunction within the mesocorticolimbic system, coupled with reduced prefrontal cortical connectivity, according to a report published online in JAMA Psychiatry.

Researchers at UCLA used a performance test known as the Balloon Analogue Risk Task to assess risk-taking and maladaptive decision-making in 25 methamphetamine-dependent and 27 healthy comparison subjects. The task involved the choice to pump a balloon or to cash out of the task in the context of uncertain risk. Functional magnetic resonance imaging was used to study subjects' brain activity at rest and when performing the performance task. The researchers measured resting-state functional connectivity, as well as the degree to which activation in the striatum and right dorsolateral prefrontal cortex changed as a linear function of risk and potential reward while performing the task.

They reported that methamphetamine-dependent subjects showed important differences in resting-state connectivity—especially heightened connectivity within the mesocorticolimbic system—and reduced prefrontal cortical connectivity during the performance task.

“Heightened resting-state connectivity within the mesocorticolimbic system, coupled with reduced prefrontal cortical connectivity, may create a bias toward reward-driven behavior over cognitive control in methamphetamine users,” the researchers suggested. “Interventions to improve this balance may enhance treatments for stimulant dependence and other disorders that involve maladaptive decision making.”

To read more about brain changes and methamphetamine use, see the Psychiatric News article, "Psychotic Symptoms Increase With More Frequent Meth Use."

(Image: iQoncept/shutterstock.com)