title: BDNF Val66Met genotype and 6-month remission rates in late-life depression.
abstract: Although not observed in younger adult cohorts, in older individuals the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is associated with major depressive disorder (MDD) risk. It is further associated with subjective social support and magnetic resonance imaging (MRI) hyperintense lesions, clinical features independently related to MDD. We examined the relationship between this polymorphism and antidepressant remission rates in an elderly sample with MDD, while also testing for mediation effects of social support and hyperintensities. A total of 229 elderly Caucasian subjects with MDD completed baseline assessments, 1.5 T MRI, and BDNF genotyping. They received antidepressant medication under a structured treatment algorithm and were evaluated for remission at 3 and 6 months. At the 3-month evaluation, BDNF Val66Met genotype was not associated with remission (Wald's χ²=2.51, P=0.1131). When not controlling for multiple comparisons, Met66 allele carriers were more likely to be remitted at 6 months (χ²=4.32, P=0.0377) with an odds ratio of 1.82 (95% CI: 1.04, 3.22). This effect persisted after controlling for lesion volume and social support, neither of which mediated this relationship. Thus in this exploratory analysis, the Met66 allele may be associated with increased odds of remission in older subjects, but also with increased time to remission as there was no 3-month effect.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA. taylo066@mc.duke.edu
authors.forename: W D
authors.initials: WD
authors.lastname: Taylor
authors.forename: D R
authors.initials: DR
authors.lastname: McQuoid
authors.forename: A
authors.initials: A
authors.lastname: Ashley-Koch
authors.forename: J R
authors.initials: JR
authors.lastname: MacFall
authors.forename: J
authors.initials: J
authors.lastname: Bridgers
authors.forename: R R
authors.initials: RR
authors.lastname: Krishnan
authors.forename: D C
authors.initials: DC
authors.lastname: Steffens
mesh_terms: D000368:Aged; D019943:Amino Acid Substitution; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D003865:Major Depressive Disorder / Q000188:drug therapy*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008715:Methionine / Q000235:genetics; D008875:Middle Aged; D017354:Point Mutation / Q000235:genetics; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D012074:Remission Induction; D014633:Valine / Q000235:genetics; D044465:White People / Q000235:genetics
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D008715:Methionine; D014633:Valine