The Effects of Nicotine on Cognition in Schizophrenia

We propose to test the efficacy and safety of transdermal nicotine for attention and working memory in outpatients with stable symptoms of schizophrenia treated with high potency antipsychotic medications that do not smoke cigarettes or use nicotine-containing products. This is a randomized, double-blind, placebo-controlled pilot study to determine whether transdermal nicotine, initiated in a clinic setting and dosed for four hours is safe and effective for improving attention and spatial working memory deficits in patients with schizophrenia. This is an add-on study, subjects will continue with their usual medications and treatments throughout. Subjects are 30- non-smoking outpatients with stable treated schizophrenia and 30 normal controls who do not have a major mental illness and who are matched for age sex and parental education. Subjects are randomized to one of 2 groups for order of receiving active and placebo patch, using a computer generated random number sequence. Randomization is concealed using opaque envelopes. Assessors and subjects are blind to group allocation. The primary outcome measure is d' measure on the CPT-IP following a 4 hour administration of the transdermal nicotine patch. Secondary outcome measures are performance on tasks assessing attention, numeric and visuospatial working memory, psychomotor ability, executive functioning and motivation for reward following nicotine patch administration. Specific Aims 1. To evaluate the effectiveness of transdermal nicotine compared with placebo for attentional impairment in patients with schizophrenia Hypothesis 1.1: Subjects will demonstrate greater signal detection as measured by the d' (hits vs. false alarms) on the Continuous Performance Test Identical Pairs Version (CPT-IP) following 4-hour nicotine administration when compared with placebo administration. Hypothesis 1.2: Subjects will demonstrate decreased false alarms on the CPT-IP following 4-hour nicotine administration when compared with placebo administration. Hypothesis 1.3: Subjects will demonstrate decreased reaction time on the CPT-IP following 4- hour nicotine administration when compared with placebo administration. 2. To evaluate the effect of transdermal nicotine in patients with schizophrenia compared with normal matched controls Hypothesis 2.1: Schizophrenia subjects will demonstrate greater improvement in signal detection as measured by the d' (hits vs. false alarms) on the Continuous Performance test identical pairs version(CPT-IP) following 4-hour nicotine administration when compared with normal controls. Hypothesis 2.2: Schizophrenia subjects will demonstrate greater reduction in false alarms on the CPT-IP following 4-hour nicotine administration when compared with normal controls. Hypothesis 2.3: Schizophrenia subjects will demonstrate decreased reaction time on the CPT-IP following 4- hour nicotine administration when compared with normal controls. Performance Test Identical Pairs Version