An addict's brain looks different than the average brain on multicolored brain scans. The prefrontal cortex, with its decision-making function, lights up like a bonfire with rapid-firing synapses linked to craving and compulsive behavior.

In color MRI images, an average person's brain resembles a broad meadow of soft green, with pockets of soothing yellow and a few flecks of red. An addict's brain is marked by large, fiery explosions of red embedded in a sea of harsh yellow surrounded by small islands of green.

Scientists can measure the effects of this brain disease. Addiction is not a character flaw or sign of moral weakness, they note, and it's not the exclusive to humans. In experiments with lab mice, the rodents will continue to take ever-increasing amounts of alcohol and drugs until they die.

"Addiction is a chronic, relapsing disorder. The brain structure and how it works is changed by long-term alcohol and drug abuse," said David Friedman, co-founder and director of the Addiction Studies Program at Wake Forest University of Medicine.

Source: http://www.timesunion.com/AspStories/story.asp?storyID=857105&category=ALBANY&TextPage=1