title: Executive attention in schizophrenic males and the impact of COMT Val108/158Met genotype on performance on the attention network test.
abstract: BACKGROUND
  Executive control of attention in schizophrenia has recently been assessed by means of the Attention Network Test (ANT). In the past, for tasks assessing executive attention, findings in schizophrenia have been contradictory, among others suggesting a lack of increased stimulus interference effects. Attention and executive functioning are substantially influenced by candidate genes of schizophrenia, including the functional single-nucleotide polymorphism catechol-o-methyltransferase (COMT) Val108/158Met, with task-dependent, specific effects of Met allele load on cognitive function. Therefore, we aimed at investigating executive attention in schizophrenic patients (SZP) as compared with healthy controls (HC), and to assess the specific impact of COMT Val108/158Met on executive attention, using ANT.
  
  
  METHODS
  We applied ANT to 63 SZP and 40 HC. We calculated a general linear model to investigate the influence of affection status and the COMT Val108/158Met genotype on executive attention as assessed by the ANT.
  
  
  RESULTS
  Multivariate analysis of variance revealed a significant effect of group on executive attention. SZP exhibited smaller conflict effects in the ANT. Met allele load significantly modulated executive attention efficiency, with homozygous Met individuals showing low overall reaction time but increased effects conflicting stimulus information in executive attention.
  
  
  CONCLUSIONS
  Our data suggest a disease-related dissociation of executive attention with reduced conflict effects in SZP. Furthermore, they support the hypothesis of differential tonic-phasic dopamine activation and specific dopamine level effects in different cognitive tasks, which helps interpreting contradictory findings of Met allele load on cognitive performance. Disease status seems to modulate the impact of COMT Val108/158Met on cognitive performance.
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité-University Medicine Berlin, Campus Benjamin Franklin, Berlin, Germany. carolin.opgen-rhein@charite.de
authors.forename: Carolin
authors.initials: C
authors.lastname: Opgen-Rhein
authors.forename: Andres H
authors.initials: AH
authors.lastname: Neuhaus
authors.forename: Carsten
authors.initials: C
authors.lastname: Urbanek
authors.forename: Eric
authors.initials: E
authors.lastname: Hahn
authors.forename: Thomas
authors.initials: T
authors.lastname: Sander
authors.forename: Michael
authors.initials: M
authors.lastname: Dettling
mesh_terms: D000328:Adult; D000483:Alleles; D001288:Attention; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D003220:Conflict, Psychological; D003463:Cues; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D009949:Orientation; D010364:Pattern Recognition, Visual; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011594:Psychometrics; D011597:Psychomotor Performance; D011930:Reaction Time / Q000235:genetics; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics*; D012565:Schizophrenic Psychology
chemical_list: D002394:Catechol O-Methyltransferase