Patients with schizophrenia have a variety cognitive deficits and nicotine has been shown to normalize some of these deficits. The purpose of this study is to investigate the effects of nicotine on cognition in schizophrenia.We will evaluate the effects of transdermal nicotine compared with placebo for attentional impairments in non-smokers with schizophrenia and controls.
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
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
60
14mg transdermal nicotine application
14mg transdermal nicotine application
Massachusetts General Hospital Schizophrenia Research Program
Boston, Massachusetts, United States
Effects of Nicotine Patch Compared With Placebo in Non- Smokers With Schizophrenia and Control Groups on Attention Measured by the Continuous Performance Test Identical Pairs Version
The primary outcome measure was attention as measured by the Continuous Performance Test Identical Pairs (CPT-IP) Version 4.0 (Biobehavioral Technologies, New York, USA), developed for use in patients with schizophrenia and normal controls. In this task, participants were asked to respond when two identical pairs of numbers were presented in sequence by pressing a mouse key as quickly as possible using the dominant hand.The stimuli were presented with increasing cognitive load in successive blocks: two-,three- and four-digit target in the first, second and third block, respectively. Hit reaction time, a standard outcome variables on the CPTIP, is presented here. It was measured 3 hrs after application of the patch
Time frame: Visit 1 and visit 2 (separated by an interval of 7-10 days)
Effects of Nicotine Patch Compared With Placebo in Non- Smokers With Schizophrenia and Control Groups on Visual Attention and Cognitive Interference as Measured by Three Card Stroop
This standard test of visual attention, processing speed and cognitive interference was performed, in which three cards (Stoelting Co., Wood Dale, IL, USA) were presented in order: the first card with color names, the second with colored patches of ink and the third with color namesprinted in incongruously colored ink. Participants were asked to read or name as many colors as possible in 45 s for each condition. The raw interference score was calculated by subtracting the predicted color-word score (calculated using raw word and color scores) from the observed raw color-word score. This value was converted to an interference T score by referring to a standardized table. A higher interference T score indicates better task performance with less interference. It was measured 3 hrs after application of the patch, after CPT
Time frame: Visit 1 and visit 2 (separated by an interval of 7-10 days)
Effects of Nicotine Patch Compared With Placebo in Non- Smokers With Schizophrenia and Control Groups on Letter Number Sequencing
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This measure of working memory and auditory attention was performed under two conditions. In the first condition, participants were read progressively longer lists of letters and numbers and instructed to repeat these exactly as given, without reordering. In the second condition, participants were read progressively longer lists of numbers and letters and instructed to re-order the list and give the numbers first in ascending order and then the letters in alphabetical order (WMS-III). The sum of the trial scores provided the item score and the sum of the item scores provided the total score.It was measured 3 hrs after application of the patch, after CPT and Stroop. The total score ranges from 0 to 21.Higher scores of Letter number sequencing means better working memory and auditory attention
Time frame: Visit 1 and visit 2 (separated by an interval of 7-10 days)
Effects of Nicotine Patch Compared With Placebo in Non- Smokers With Schizophrenia and Control Groups on Lateralized Psychomotor Speed Measured by the Grooved Pegboard
The Grooved Pegboard (model 32025 Lafayette Instrument Company, Lafayette, IN, USA). In this test of lateralized psychomotor speed, participants had 45 s to place as many pegs as possible into grooves on a board using their dominant hand. The number of correctly placed pegs were recorded for each of the two trials.It was measured 3 hrs after application of the patch after CPT, Stroop and Letter number sequencing
Time frame: Visit 1 and visit 2 (separated by an interval of 7-10 days)