Cognitive effects of very low nicotine content cigarettes, with and without nicotine replacement, in smokers with schizophrenia and controls.

INTRODUCTION: Beneficial effects of nicotine on cognitive functioning may contribute to the markedly high rates of smoking among people with schizophrenia. A reduction in the nicotine content of cigarettes to non-addictive levels is being considered as a regulatory strategy for reducing tobacco dependence in the United States. We examined whether switching to very low nicotine content (VLNC) cigarettes impairs cognitive functioning in smokers with and without schizophrenia, andwhether nicotine replacement reverses these effects.

METHODS: Smokers with schizophrenia (SS, n = 29) and control smokers matched on smoking rate but without psychiatric illness (CS, n = 28) smoked usual-brand cigarettes, VLNC cigarettes while wearing 2 placebo patches (PLA), or VLNC cigarettes while wearing 2 nicotine patches totaling 42mg (NIC) for 5hr, and then completed computerized assessments of visual sustained attention, motor speed, visual working memory, processing speed, inhibitory control, and response variability.

RESULTS: Across conditions, SS were slower than CS in tasks of motor speed and visual working memory, and had poorer target detectability on a visual sustained attention task. Across groups, functioning in domains of visual sustained attention, inhibitory control, processing speed, and response variability was impaired in the VLNC + PLA condition relative to the usual-brand and VLNC + NIC conditions.

CONCLUSIONS: Dramatically reducing the nicotine content of cigarettes may impair cognitive functioning in heavy smokers with and without schizophrenia, but the use of nicotine replacement while smoking VLNC cigarettes may preserve cognitive functioning in these smokers.