Neuroimaging Reveals Biologic Basis of Cocaine Addiction

Researchers looking at the brain activity of cocaine users may have identified a biologic ‘lack of willpower' that should help researchers understand why some individuals become long-term addicts whereas others can use the drug socially.

The investigators presented their findings at a scientific meeting at the Royal Society (London, UK), the UK's National Academy of Science, on February 26, 2008. By taking brain scans of cocaine users while they performed computer tasks that assessed both impulsive behavior and the brain's response to making a ‘mistake,' scientists from Trinity College Dublin (Ireland) have been able to identify the precise regions of the brain affected by cocaine. The investigators utilized functional magnetic resonance imaging (fMRI), a noninvasive imaging modality to show that cocaine alters the areas of the brain responsible for controlling behavior, and making appropriate decisions.

Dr. Hugh Garavan, lead researcher on the project, said, "Non-invasive brain imaging allows us to study the biology behind ‘willpower,' which until now, most people would think of as something that cannot be measured ‘objectively' using scientific investigation. This research helps us move away from thinking of drug dependence as a moral weakness and allows us to see it as more of a medical condition. Research into drug abuse has tended to focus on the emotional aspects of addiction, such as pleasure seeking, craving, and withdrawal. However, by using brain scans to study ‘impulse control,' the brain's ability to control a person's actions, we can see the direct effects that cocaine has on the brain's ability to control behavior.”

Dr. Garavan presented his research at a Royal Society discussion meeting on February 25, and 26, 2008. "Cocaine's effect on this impulse control may account for why some users find it easier to quit than others. In the future this may lead to an understanding of why some people develop long term addictions to cocaine and others don't,” Dr. Garavan additionally stated. "Understanding the role that our brain plays in addiction may also have important implications for treating long-term addiction and designing intervention therapies. Importantly, new medication based on certain chemical processes in the brain could be developed; as currently there are no good pharmacological treatments for cocaine. Traditional treatment therapy such as counseling or rehab could also be adapted to train addicts to monitor their behavior and practice impulse control.”

Dr Garavan's study also demonstrated that there are differences in the brain structures of cocaine users. This has significant consequences for how society perceives and treats addicted users. Dr Garavan noted, "It is still unclear whether the differences we see in cocaine users' brains existed before they began taking cocaine or whether they are a result of use, or both. It is more a case of trying to understand as much as possible about the underlying brain function of addicts. One would hope this research would guide the development of new treatments including the development of pharmacological solutions to addiction.”

The Royal Society is an independent academy promoting the natural and applied sciences. Founded in 1660, the Society has three roles, as the UK Academy of Science, as a learned Society, and as a funding agency.


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