New research shows for the first time that smoking produces long-lasting biochemical changes in the human brain similar to those changes previously seen in the brains of animals that used cocaine, heroin, and other illicit drugs.
This new research supports the idea that long-term smoking alters the brain in ways that contribute to addiction, and provides insight into how addiction works, says lead author Bruce Hope, PhD, of the National Institute on Drug Abuse (NIDA). The study, supported by NIDA, is published in the February 21 issue of The Journal of Neuroscience.
"The data show that there are long lasting chemical changes in the brains of humans," says Michael Kuhar, PhD, of Emory University. "The chemical changes alone suggest a physiological basis for nicotine addiction." Kuhar was not involved in this study.
Hope and his colleagues studied samples of human brain tissue from the nucleus accumbens and the ventral midbrain, brain regions that play a part in controlling addiction-related behaviors. Eight samples were taken from each of three groups: long-term smokers until the time of death, previous long-term smokers, and nonsmokers. All died of causes not related to smoking.