The reason some people smoke may be linked to hereditary factors, a Houston researcher said Tuesday. Dr. Margaret Spitz, head of the department of epidemiology at the University of Texas M.D. Anderson Cancer Center, said a study of patients with lung cancer suggests that variations in genes that affect dopamine receptors in the brain influence the probability of smoking addiction and a smoker's ability to quit.
Dopamine is a common chemical in the brain that helps pass messages between nerve cells.
Prior research has found that nicotine, alcohol, cocaine and other drugs cause the release of dopamine in areas of the brain associated with feelings of pleasure. Even after years of smoking, some individuals are able to quit the habit while others are unsuccessful despite their cessation efforts. This study sheds light on why that may occur. The study, due for publication today in the Journal of the National Cancer Institute, is small and preliminary, and needs to be duplicated by other researchers, she said. Joined by Drs.