People prone to anger and aggression may be predisposed to develop an addiction to nicotine

People prone to anger and aggression may be predisposed to develop an addiction to nicotine compared with those who have happy, relaxed personalities, report NIDA-supported researchers.

Dr. Steven Potkin and colleagues at the University of California, Irvine, administered personality tests to 31 smokers and 55 nonsmokers. Participants were grouped according to hostile (anger, impatience, irritability, nervousness) or nonhostile (happy, relaxed, and curious) personality traits. All hostile and nonhostile smokers and nonsmokers received a low-dose nicotine patch, as well as a placebo. The hostile and nonhostile smokers also received a highdose nicotine patch that produced blood levels of the chemical comparable to smoking a cigarette. The researchers used positron emission tomography (PET) to measure the participants’ brain metabolic activity while performing an aggression task.

The PET scans showed no metabolic changes in the brains of low-hostility smokers and nonsmokers in response to either dose of nicotine. When the researchers analyzed PET scans from the high-hostility smokers and nonsmokers they found that the high-dose nicotine patch induced dramatic metabolic responses in the brains of smokers, while the low-dose nicotine patch elicited changes in the brains of nonsmokers. These changes occurred in the parts of the brain that control emotion, social response, attention, and language.

Thus, persons easy to anger have an increased brain response to nicotine, the scientists say. Since this occurs in smokers and nonsmokers it may help explain why people who are easy to anger are more susceptible to becoming addicted to cigarettes.

These findings may help explain why some people are more likely to become addicted to nicotine or express more of the mood consequences of trying to quit.

This study was published in the February 2004 issue of Cognitive Brain Research.