Rationale: There is abundant evidence from clinical and preclinical studies that acute administration of nicotine has beneficial effects on attentional network function in the brain. In contrast, little is known about potentially neurotoxic effects on the attentional network during neurodevelopmentally critical periods, such as during adolescence and early adulthood.
Methods: Using event-related functional MRI (fMRI), we investigated prefrontal attentional network function in young adults (n=15 regular smokers and n=12 never-smokers; age: 22.6+/-1.5 years). Duration of smoking was 6.9+/-2.3 years (range of 2-10). Smokers were allowed to smoke ad libitum before the fMRI scanning was conducted.
Results: As expected from literature, prefrontal attentional network activity was significantly reduced in smokers compared to nonsmokers (Z=2.1; P=0.036). In smokers, we found that the history of smoking duration (years) is directly related to the extent of diminished attentional network activity (R=-0.67; P=0.012).
Conclusions: To our best knowledge, the relationship between the duration of smoking history and prefrontal attentional network function has not yet been reported. This finding might suggest that several years of chronic nicotine abuse may be sufficient to exert long-lasting effects on the brain function of adolescents and young adults.