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Extant evidence suggests a possibility of self-medication to account for greater prevalence of cigarette smoking among adults with ADHD as they tend to show improvements on affective and cognitive measures, particularly on measures of sustained attention following nicotine administration. The present study was conducted to evaluate whether adult non-smokers with low attentiveness might exhibit greater improvements on measures of sustained attention than those with higher attentiveness using neuropsychological tests that had previously shown sensitivity to ADHD. On the basis of their scores on attention scales used in the diagnosis of adult ADHD, 62 male non-smokers were divided into 2 groups of either low or high attentiveness and treated with either a placebo or 7 mg nicotine patch. After 6 h of patch application each participant completed the Wisconsin Card Sorting Test (WCST), classic Stroop task, and Conners' Continuous Performance Test (CPT), which were administered in a counterbalanced order and a double-blind manner. No significant drug or group differences were observed on the Stroop task. On the Conners' CPT participants in the low attention group treated with nicotine committed significantly fewer errors of commission, showed improved stimulus detectability and fewer perseverations than those in the low attention placebo group. On the WCST nicotine significantly impaired the ability of participants in the high attention group to learn effective strategies to complete the test with fewer trials. The results showed nicotine-induced improvement on some measures of sustained attention in the low attention group and some decrement in working memory in the high attention group, which suggests that nicotine tends to optimize rather than improve performance on cognitive tasks.

Previous research investigating cognitive effects of nicotine has produced mixed findings partly due to the use of abstaining smokers and cigarettes as a delivery system. The present study examined effects of nicotine delivered via a transdermal patch on prose memory and sustained attention in male smokers (n=25) and nonsmokers (n=22), who were randomly assigned to either a placebo or a nicotine condition. All groups were matched on their verbal ability and gross personality characteristics (state/trait anxiety levels, extroversion-introversion, and impulsivity level). In the nicotine condition, smokers were treated with a 21-mg transdermal patch, while nonsmokers received a 7-mg nicotine patch. Six hours following patch application, their performance was assessed on a computerized prose memory task and the Rapid Visual Information Processing task (RVIP) in a counterbalanced order and double-blind fashion. The results demonstrated that smokers in the placebo group recalled a significantly greater number of propositions than their counterparts in the nicotine group. Nonsmokers in the nicotine condition also remembered significantly more of the prose material than smokers in the same condition and showed a trend towards better recall of propositions of medium importance in the nicotine condition in comparison to the nonsmokers in the placebo group. No between-group differences were found on the RVIP task. A significant effect of time was found for systolic blood pressure and heart rate. The results cannot be interpreted using the arousal theory of nicotine effects on attention and are explained on the basis of a dose-dependent nicotinic action possibly recruiting cholinergic cortical projections.