PET is also being used to show brain changes following chronic drug abuse, during withdrawal from drug use, and during the experience of drug craving. In addition, PET can be used to assess the effects of pharmacological and behavioral therapies for drug addiction on the brain.
Scientists have the ability to see how cocaine actually affects brain function in people.
The left scan is taken from a normal, awake person. The right scan is taken from someone using cocaine. Note that there are many areas of the brain that have reduced metabolic activity. Serotonin is fundamental to the brain's integration of information and emotion. Brighter colors in the PET scans indicate that more serotonin is being transported than do duller colors.