Linked to Dopamine Levels Scientists at the Department of Energy's Brookhaven National Laboratory found that dopamine, a brain chemical associated with addiction to cocaine, alcohol, and other drugs, may also play an important role in obesity. Dopamine, a neurotransmitter naturally produced in the brain, plays a key role in the function of the reward circuit and in modifying mental and physical activity.
Drug addicts have fewer dopamine receptors than normal subjects, resulting in low dopamine activity.
Scientists at Brookhaven found that obese subjects also had fewer dopamine receptors than normal-weight subjects. Although a variety of dopamine-enhancing drugs are available, many have undesirable side effects. The Brookhaven study was supported by DOE's Office of Science, Division of Biological and Environmental Sciences. New research on the drug Ritalin, reported in the January 15 issue of the Journal of Neuroscience , shows for the first time how the drug acts in the human brain and why it is so effective. The Brookhaven study, on humans, indicates that Ritalin, given at doses commonly used to treat children with ADHD, significantly increases levels of dopamine in the brain, thereby stimulating attention and motivational circuits that enhance one's ability to focus and complete tasks.