Scientists Chart Nicotine Craving's Impact On Mental Skills

New research suggests that while abstinence increases a smoker's craving, it may harm smokers' performance on some mental tasks while leaving their performance on others unchanged.

"It is likely that craving and impaired concentration, in part, function to maintain smoking in nicotine-dependent individuals and to increase the probability that a smoker attempting to quit will relapse," says Stephen J. Heishman, PhD, of the National Institute on Drug Abuse, Baltimore, and colleagues, reporting in the premier issue of the journal, Nicotine & Tobacco Research.

One of the more surprising findings reported is that when smokers abstain from cigarettes their reasoning skills do not seem to decrease, but when they resume smoking they actually appear to improve.

"A more complete understanding of tobacco craving and the influence of smoking on cognitive performance should enhance our ability to treat these symptoms of nicotine withdrawal, thereby increasing the probability of successful smoking cessation efforts," they write.

The investigators studied the effects of smoking and abstinence on 20 smokers who completed two computerized tests before and after smoking one afternoon and again after being deprived of cigarettes for 18 hours. The participants typically smoked 23 cigarettes daily and had been smoking for more than 17 years, on average.

In one test, smokers were instructed to find specific pairs of letters in a sequence of 20 other letters. The other test presented them with a series of letter pairs and statements and was designed to measure their ability to reason.

Responses revealed that the smokers' cravings for cigarettes increased significantly over the 18-hour abstinence. After they had been allowed to smoke again, however, their cravings subsided to the levels observed at the beginning of the study.

On the letter-search test, the smokers took longer to complete the task when deprived of cigarettes, but their speed improved to baseline levels after smoking. On the test of logical reasoning, however, performance did not decrease after abstinence, but actually improved after smoking. Neither smoking nor abstinence had any effect on smokers' accuracy on the two tasks.

The investigators were also surprised to find that performance on the logical reasoning test, the more difficult of the two, was not impaired when smokers were deprived of their cigarettes, despite clear evidence that their cravings had increased. It is possible, they say, that smokers' ability to maintain attention, necessary to complete the letter-search task, was more compromised by tobacco abstinence than was their ability to process verbal information, which was required in the logical reasoning test.