title: Smoking improves divided attention in schizophrenia.
abstract: BACKGROUND
  Smoking is highly prevalent in schizophrenia, and there is evidence for beneficial effects on neurocognition. Smoking is therefore hypothesized a self-medication in schizophrenia. Although much effort is devoted to characterize those cognitive domains that potentially benefit from smoking, divided attention has not yet been investigated.
  
  
  OBJECTIVE
  The aim of this study was to analyze the interactional effects of diagnosis of schizophrenia and smoking history on divided attention.
  
  
  METHODS
  We investigated behavioral measures of divided attention in a sample of 48 schizophrenic patients and 48 controls (24 current smokers and non-smokers each) carefully matched for age, sex, education, verbal IQ, and smoking status with general linear models.
  
  
  RESULTS
  Most important within the scope of this study, significant interactions were found for valid reactions and errors of omission: Performance substantially increased in smoking schizophrenic patients, but not in controls. Further, these interactions were modified by sex, driven by female schizophrenic patients who showed a significant behavioral advantage of smokers over non-smokers, other than male schizophrenic patients or healthy controls who did not express this sex-specific pattern.
  
  
  CONCLUSIONS
  Results suggest a positive effect of smoking history on divided attention in schizophrenic patients. This study provides first evidence that the complex attention domain of divided attention is improved by smoking, which further substantiates the self-medication hypothesis of smoking in schizophrenia, although this has been shown mainly for sustained and selective attention. Gender-specific effects on cognition need to be further investigated.
authors.affiliation: Department of Psychiatry, Charité University Medicine, Campus Benjamin Franklin, Eschenallee 3, 14050, Berlin, Germany, eike.ahlers@charite.de.
authors.forename: Eike
authors.initials: E
authors.lastname: Ahlers
authors.forename: Eric
authors.initials: E
authors.lastname: Hahn
authors.forename: Thi Minh Tam
authors.initials: TM
authors.lastname: Ta
authors.forename: Elnaz
authors.initials: E
authors.lastname: Goudarzi
authors.forename: Michael
authors.initials: M
authors.lastname: Dettling
authors.forename: Andres H
authors.initials: AH
authors.lastname: Neuhaus
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001288:Attention / Q000187:drug effects*; D003071:Cognition / Q000187:drug effects; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects; D012559:Schizophrenia / Q000188:drug therapy; D012565:Schizophrenic Psychology; D012907:Smoking / Q000523:psychology*; D055815:Young Adult