Effects of a single transdermal nicotine dose on cognitive performance in adults with Down syndrome

Subjects with Down syndrome exhibit various types of cognitive impairment. Neuropathological and neurochemical studies revealed similarities between Down syndrome and Alzheimer's disease, cholinergic deficits being the most consistent findings. To explore the potential for cognitive enhancement utilizing nicotinic stimulation, 8 patients with Down syndrome (aged 18.5-31 years) received placebo and a single dose of transdermal nicotine (5 mg patch) over 2h in a single-blind, within-subjects repeated measures design. Auditory event-related potentials (ERPs) and neuropsychological tests, comprising digit symbol performance subtest from WAIS-R and the Frankfurt Attention Inventory (FAIR) were performed. Effects of nicotine administration in Down syndrome individuals were a decrease of ERP-P3 latency in 7 of 8 subjects (electrode position Cz: 386.9+/-24.0 ms vs. 363.1+/-26.9.2 ms, placebo vs. nicotine, respectively; P = 0.058) and an increase of ERP-P3 amplitude in 6 of 8 subjects (electrode position Cz: 17.4+/-5.5 vs. 18.0+/-4.5 microV, placebo vs. nicotine respectively; P = 0.725). Neuropsychological tests exhibited improvements in digit symbol performance subtest in 4 of 8 subjects and 7 of 8 subjects in the Frankfurt Attention Inventory. These results suggest that stimulating central nicotinic receptors might have an acute cognitive benefit in young adult Down syndrome subjects.