Using magnetic resonance imaging (MRI) and other brain mapping techniques, the researchers, led by Dr. Teresa R. Franklin, examined 13 men who had used cocaine for an average of 13 years each. They found that, compared to controls who had never used cocaine, select regions of the brains of the cocaine users had less gray matter. This decrease in critical working brain tissue ranged from 5 to 11 percent. This is the first time in either animal or human studies that differences in gray matter concentrations have been found in chronic cocaine users.
The investigators suggest that some of the behaviors observed in chronic cocaine use– such as choosing immediate gratification over long-term reward; engaging in risky behaviors, particularly when attempting to obtain cocaine; and succumbing to the overwhelming desire to seek and use drugs undeterred by the prospect of future negative consequences– may be a result of these gray matter deficiencies.
WHAT IT MEANS: Understanding the long-term impact that cocaine can have on the brain and cognition will help scientists to develop strategies to reverse those effects and, and, ultimately, restore the brain to normal function.
The study was published in the January, 2002 issue of Biological Psychiatry. It was funded by the National Institute on Drug Abuse (NIDA).
Biological Psychiatry