title: Tryptophan hydroxylase 1 gene (TPH1) moderates the influence of social support on depressive symptoms in adults.
abstract: BACKGROUND
  Tryptophan hydroxylases (TPHs) are involved in the biosynthesis of serotonin and are therefore candidate genes for psychiatric disorders, including depression. We examined whether the common 218 A > C and 779 A > C polymorphisms in the tryptophan hydroxylase 1 gene (TPH1) moderated the association between perceived social support and sub-clinical depressive symptoms in adults.
  
  
  METHODS
  The subjects were a randomly selected subsample (n=341) of individuals participating in the Cardiovascular Risk in Young Finns study, who had data on social support on one assessment time and depressive symptoms on two assessment times. Social support was assessed on the Perceived Social Support Scale Revised (PSSS-R) and depressive symptoms on a modified version of the Beck's Depression Inventory (BDI).
  
  
  RESULTS
  We found that low social support predicted depressive symptoms more strongly in individuals carrying A alleles of the TPH1 than in others. The interaction effect was observed in a cross-sectional analysis and when predicting depressive symptoms over a four-year period.
  
  
  CONCLUSIONS
  We did not have data on TPH2, which has recently been identified as the primary TPH isomorphism affecting serotonin synthesis in the brain.
  
  
  CONCLUSIONS
  TPH1 gene may be involved in the development of depressive symptoms by moderating the impact of depressogenic social influences.
authors.affiliation: Department of Psychology, University of Helsinki, Finland.
authors.forename: Markus
authors.initials: M
authors.lastname: Jokela
authors.forename: Katri
authors.initials: K
authors.lastname: Räikkönen
authors.forename: Terho
authors.initials: T
authors.lastname: Lehtimäki
authors.forename: Riikka
authors.initials: R
authors.lastname: Rontu
authors.forename: Liisa
authors.initials: L
authors.lastname: Keltikangas-Järvinen
mesh_terms: D000328:Adult; D000483:Alleles; D003863:Depression / Q000235:genetics* / Q000523:psychology*; D004777:Environment; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007438:Introns / Q000235:genetics; D008297:Male; D011110:Polymorphism, Genetic / Q000235:genetics; D012944:Social Support; D011795:Surveys and Questionnaires; D014365:Tryptophan Hydroxylase / Q000235:genetics*
chemical_list: C497467:TPH1 protein, human; D014365:Tryptophan Hydroxylase