Effects of nicotine on cognitive deficits in schizophrenia.
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.
Harris
Josette G
JG
Department of Psychiatry, University of Colorado School of Medicine, Denver, CO 80262, USA. josette.harris@uchsc.edu
Kongs
Susan
S
Allensworth
Diana
D
Martin
Laura
L
Tregellas
Jason
J
Sullivan
Bernadette
B
Zerbe
Gary
G
Freedman
Robert
R
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
D002638:Chewing Gum; D018722:Nicotinic Agonists; D009538:Nicotine