title: Genome-wide association study of co-occurring anxiety in major depression.
abstract: OBJECTIVE
  Co-morbidity between depression and anxiety disorders is common. In this study we define a quantitative measure of anxiety by summating four anxiety items from the SCAN interview in a large collection of major depression (MDD) cases to identify genes contributing to this complex phenotype.
  
  
  METHODS
  A total of 1522 MDD cases dichotomised according to those with at least one anxiety item scored (n = 1080) and those without anxiety (n = 442) were analysed, and also compared to 1588 healthy controls at a genome-wide level, to identify genes that may contribute to anxiety in MDD.
  
  
  RESULTS
  For the quantitative trait, suggestive evidence of association was detected for two SNPs, and for the dichotomous anxiety present/absent ratings for three SNPs at genome-wide level. In the genome-wide analysis of MDD cases with co-morbid anxiety and healthy controls, two SNPs attained P values of < 5 × 10⁻⁶. Analysing candidate genes, P values ≤ 0.0005 were found with three SNPs for the quantitative trait and three SNPs for the dichotomous trait.
  
  
  CONCLUSIONS
  This study provides an initial genome-wide assessment of possible genetic contribution to anxiety in MDD. Although suggestive evidence of association was found for several SNPs, our findings suggest that there are no common variants strongly associated with anxious depression.
authors.affiliation: MRC SGDP Centre, Institute of Psychiatry, King's College London , London , UK.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Schosser
authors.forename: Amy W
authors.initials: AW
authors.lastname: Butler
authors.forename: Rudolf
authors.initials: R
authors.lastname: Uher
authors.forename: Mandy Y
authors.initials: MY
authors.lastname: Ng
authors.forename: Sarah
authors.initials: S
authors.lastname: Cohen-Woods
authors.forename: Nick
authors.initials: N
authors.lastname: Craddock
authors.forename: Mike J
authors.initials: MJ
authors.lastname: Owen
authors.forename: Ania
authors.initials: A
authors.lastname: Korszun
authors.forename: Michael
authors.initials: M
authors.lastname: Gill
authors.forename: John
authors.initials: J
authors.lastname: Rice
authors.forename: Joanna
authors.initials: J
authors.lastname: Hauser
authors.forename: Neven
authors.initials: N
authors.lastname: Henigsberg
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Maier
authors.forename: Ole
authors.initials: O
authors.lastname: Mors
authors.forename: Anna
authors.initials: A
authors.lastname: Placentino
authors.forename: Marcella
authors.initials: M
authors.lastname: Rietschel
authors.forename: Daniel
authors.initials: D
authors.lastname: Souery
authors.forename: Martin
authors.initials: M
authors.lastname: Preisig
authors.forename: Ian W
authors.initials: IW
authors.lastname: Craig
authors.forename: Anne E
authors.initials: AE
authors.lastname: Farmer
authors.forename: Cathryn M
authors.initials: CM
authors.lastname: Lewis
authors.forename: Peter
authors.initials: P
authors.lastname: McGuffin
mesh_terms: D001007:Anxiety / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D016022:Case-Control Studies; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D005060:Europe / Q000453:epidemiology; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study / Q000379:methods*; D005838:Genotype; D006801:Humans; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012720:Severity of Illness Index