title: Effects of nicotine on cognitive deficits in schizophrenia.
abstract: Several lines of evidence suggest a pathophysiological role for nicotinic receptors in schizophrenia. Activation by nicotine alters physiological dysfunctions, such as eye movement and sensory gating abnormalities, but effects on neuropsychological performance are just beginning to be investigated. Nicotine-induced desensitization and the well-known tachyphylaxis of nicotinic receptors may confound such efforts. In all, 20 schizophrenics, 10 smokers, and 10 nonsmokers were assessed following the administration of nicotine gum and placebo gum. The Repeatable Battery for the Assessment of Neuropsychological Status was administered. Nicotine affected only the Attention Index; there were no effects on learning and memory, language, or visuospatial/constructional abilities. Attentional function was increased in nonsmokers, but decreased in nicotine-abstinent smokers after nicotine administration. The effects of nicotine in schizophrenia do not extend to all areas of cognition. Effects on attention may be severely limited by tachyphylaxis, such that decremented performance occurs in smokers, while modest effects may be achieved in nonsmokers.
authors.affiliation: Department of Psychiatry, University of Colorado School of Medicine, Denver, CO 80262, USA. josette.harris@uchsc.edu
authors.forename: Josette G
authors.initials: JG
authors.lastname: Harris
authors.forename: Susan
authors.initials: S
authors.lastname: Kongs
authors.forename: Diana
authors.initials: D
authors.lastname: Allensworth
authors.forename: Laura
authors.initials: L
authors.lastname: Martin
authors.forename: Jason
authors.initials: J
authors.lastname: Tregellas
authors.forename: Bernadette
authors.initials: B
authors.lastname: Sullivan
authors.forename: Gary
authors.initials: G
authors.lastname: Zerbe
authors.forename: Robert
authors.initials: R
authors.lastname: Freedman
mesh_terms: D000328:Adult; D001288:Attention / Q000187:drug effects; D002638:Chewing Gum; D003072:Cognition Disorders / Q000188:drug therapy* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009538:Nicotine / Q000097:blood / Q000627:therapeutic use*; D018722:Nicotinic Agonists / Q000097:blood / Q000627:therapeutic use*; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects; D012559:Schizophrenia / Q000150:complications*; D016037:Single-Blind Method; D012907:Smoking / Q000188:drug therapy; D013997:Time Factors; D014705:Verbal Behavior / Q000187:drug effects
chemical_list: D002638:Chewing Gum; D018722:Nicotinic Agonists; D009538:Nicotine