Evaluating the cognitive effects of Bupropion HCl during smoking cessation using event-related brain potentials

Erdem, O.1, Demiralp, T.2, Ozdemir, O.1, Ergen, M.2, and Cuhadaroglu C.3
1Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Turkey; 2Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, Turkey; 3Department of Chest Diseases, Istanbul Faculty of Medicine, Istanbul University, Turkey
E-mail: ozge_erdem@hotmail.com

Objective: To measure the cognitive effects of Bupropion SR on heavy tobacco smokers during Bupropion SR treatment by event-related brain potentials (ERPs).

Materials & Methods: P3a and P3b ERPs of 10 smokers were evaluated using the Novelty P3 paradigm. The ERPs were recorded after abstaining overnight and after the first dose, and additionally on the 7th and 45th days of the therapy. Repeated measures ANOVA was applied for the statistical analyses.

Results: The examination of electrophysiological data with respect to drug use showed that there was a significant overall increase (p<0.05) in P2 latency after 7 days of Bupropion treatment in responses to standard stimuli. Drug use x topography interaction induced a trend-level increase in P3b amplitude (p=0.07) at the parietal area after the first dose. On the other hand, there was a significant increase (p<0.05) in P3a amplitude at the parieto-central area due to chronical use of Bupropion SR.

Conclusions: The reduction of P3a at the frontal area suggests a decreased distractibility due to task-irrelevant novel events, which may be interpreted as an augmentation of focused attention to task-relevant target events. The increase in P3b at the parietal area is in line with this hypothesis. Based on Broadbent’s dual process arousal mechanism, it is suggested that noradrenergic activation helps to focus on task-relevant behaviours by attenuating the influence of distracting stimuli. Therefore, we can assume that the augmentation of focused attention by bupropion is mediated by its noradrenergic mechanisms.