title: The functional Val158Met polymorphism in catechol-O-methyltransferase (COMT) is associated with depression and motivation in men from a Swedish population-based study.
abstract: BACKGROUND
  Environmental risk factors together with genetic vulnerability create a complex background to develop depression.
  
  
  METHODS
  We investigated the associations between COMT Val(158)Met and depression in a Swedish population-based sample of 405 depressed individuals (major depression diagnosis, dysthymia or mixed anxiety depression defined according to DSM-IV) and 2,151 healthy controls. We also analyzed interaction between this genetic variation and some environmental risk factors for depression and the link between this polymorphism and the low motivational level and negative mood state found in depressed individuals.
  
  
  RESULTS
  Depressed individuals displayed a higher frequency of the Met/Met and Met/Val genotypes compared to controls (OR=1.49, CI(95%)=1.11-2.00, P=0.009). The association was found among men only (OR=2.26, CI(95%)=1.26-4.05, p=0.008). Regression analysis including some potential risk factors for depression, did further indicate that Met/Met and Met/Val were associated with depression in men (P=0.005). There was also an interaction between genotype and family childhood problems (RERI=0.876, CI(95%)=0.090-1.662 and AP=0.426, CI(95%)=0.030-0.821). Further, depressed men homozygous for the Val-allele, had a higher motivational level than depressed men with a Met-variant (P=0.02).
  
  
  CONCLUSIONS
  The sample size of depressed individuals per group when stratifying cases according to gender and genotypes is considered a limitation.
  
  
  CONCLUSIONS
  The Met-variants of COMT Val(158)Met are risk variants for depression and low motivational level in depressed Swedish men, but not women. Individuals with this risk variant in combination with a problematic childhood, have an even higher risk to develop depression.
authors.affiliation: Neurogenetics Unit, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden. elin.aberg@ki.se
authors.forename: Elin
authors.initials: E
authors.lastname: Åberg
authors.forename: Andrés
authors.initials: A
authors.lastname: Fandiño-Losada
authors.forename: Louise K
authors.initials: LK
authors.lastname: Sjöholm
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Forsell
authors.forename: Catharina
authors.initials: C
authors.lastname: Lavebratt
mesh_terms: D000328:Adult; D000483:Alleles; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D003866:Depressive Disorder / Q000201:enzymology / Q000235:genetics*; D003865:Major Depressive Disorder / Q000201:enzymology / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009042:Motivation / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology
chemical_list: D002394:Catechol O-Methyltransferase