Modafinil is a popular drug used by people who want or need to stay alert. It has become a popular stimulant, used by soldiers to stay awake and by citizens looking for a safe brain boost, including one in 10 researchers. The FDA issued their “Approved” stamp for it to be used for treating narcolepsy and sleep disorders in 1998. At that time, scientists claimed that it did not change levels of dopamine in those who took the drug. Increases in dopamine levels are considered a chemical signature of possible addictiveness to a drug. Since its FDA approval, modafinil is now being used “off-label” to treat depression, Parkinson’s disease and fatigue.
However, the March 2009 issue of JAMA published this study;
Volkow N, et. al., Effects of Modafinil on Dopamine and Dopamine Transporters in the Male Human Brain., JAMA, Vol. 301, No. 11, March 18, 2009.
You can read more on this report at the Wired Science Blog.