Early nicotine withdrawal and transdermal nicotine effects on neurocognitive performance in schizophrenia.

As cigarette smoking prevalence rates approach 90% in schizophrenia, an important emerging question is the role of nicotine in the disease-related disturbance in cognition. We therefore tested a total of 38 male cigarette smokers (22 schizophrenia, 16 normal control), matched on nicotine dependence, on the Attention Network Test (ANT) at three nicotine conditions (baseline, 8 h overnight withdrawal, 3 h 21 mg nicotine patch). The results indicated that the groups did not differ in performance on either of three ANT measures (alertness, orienting, and executive) across baseline, patch, and withdrawal conditions. However, in comparison to the controls, the participants with schizophrenia showed faster ANT reaction time (RT) for the nicotine patch in relation to the baseline condition. In comparison to controls, the participants with schizophrenia also showed reduced ANT accuracy at withdrawal but not at patch condition. These results suggest that overall processing speed and accuracy are affected differently by nicotine levels in participants with schizophrenia, with evidence supporting greater impairment from withdrawal and greater improvement from nicotine administration.