Home » Rigor and RelevanceSpring 2011

Got Shopping on the Brain? Blame the Dopamine.

by Cindy Thomsen No Comment

You probably know someone who just can’t resist a good deal. Chances are they’re on a first-name basis with their UPS delivery person, have a closet full of unworn clothes, and every gadget under the sun stuffed in their kitchen drawers.

Two College of Arts and Science researchers, David Zald, associate professor of psychology, and Joshua Buckholtz, a Ph.D. candidate, have learned that people who act impulsively—perhaps buying everything they see advertised on television—may have higher-than-normal levels of a chemical called dopamine in their brain.

All healthy brains manufacture dopamine, which has important roles in behavior, cognition, voluntary movement, sleep, mood, attention, working memory, learning and more. Dopamine also affects impulsivity and even the urge to acquire things. In healthy brains, sensors keep dopamine at proper levels. But some people have a specific deficit in the way the brain regulates dopamine. In those brains, the levels increase and rash behavior increases as well.

“You can think of it as very similar to a thermostat,” Buckholtz says. “The brain has a number of different thermostats, which sense the levels of certain brain chemicals and adjust the output of those chemicals accordingly. We show that one particular thermostat-like mechanism—midbrain autoreceptor regulation of striatal dopamine release—is out of whack in people with high levels of trait impulsiveness.”

During their collaboration, Zald and Buckholtz scanned the brains of 32 healthy volunteers with varying levels of impulsivity. Those characterized as more impulsive were given a drug that releases dopamine and their brains were rescanned.

“The people who scored highest on our trait measure of impulsivity had upwards of four times the amount of dopamine released,” Buckholtz says.

Because dopamine is produced in the area of the brain associated with reward, excessive levels can lead to much more destructive behavior than overspending—it can cause a strong craving for stimulants such as cocaine and methamphetamine. Additionally, people who tend to seek rewards without considering the consequences may not be able to stop their actions.

A certain amount of impulsive behavior is a good thing, and can lead to creativity. However, Buckholtz and Zald hope that their findings will lead to a better understanding of—and better treatment for—certain psychiatric disorders that involve impulsive behavior. One outcome could be more targeted drug therapies that help the brain’s “thermostats” regulate dopamine levels.

illustration credit: iStock/© Tatiana Georgieva

Comments are closed.