title: Depression, 5HTTLPR and BDNF Val66Met polymorphisms, and plasma BDNF levels in hemodialysis patients with chronic renal failure.
abstract: OBJECTIVE
  Depression is the most prevalent comorbid psychiatric disease among hemodialysis patients with end-stage renal disease. This cross-sectional study investigated whether depression in hemodialysis patients is associated with the polymorphism of the 5' flanking transcriptional region (5-HTTLPR) of the serotonin transporter gene, the valine (Val)-to-methionine (Met) substitution at codon 66 (Val66Met) polymorphism of the brain-derived neurotrophic factor (BDNF) gene, or plasma BDNF levels.
  
  
  METHODS
  A total of 188 participants (mean age: 58.5±14.0 years; 89 men and 99 women) receiving hemodialysis at the Chang Gung Memorial Hospital were recruited. The diagnosis of major depressive disorder (MDD) was confirmed using the Chinese version of the Mini International Neuropsychiatric Interview. The genotypes of 5-HTTLPR and BDNF Val66Met were conducted using polymerase chain reactions plus restriction fragment length polymorphism analysis. The plasma BDNF levels were measured using an enzyme-linked immunosorbent assay kit.
  
  
  RESULTS
  Forty-five (23.9%) patients fulfilled the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV-TR) criteria for a MDD. There were no significant effects of the 5-HTTLPR or BDNF Val66Met gene polymorphism on MDD among the hemodialysis patients. The plasma BDNF levels correlated significantly with age (P=0.003) and sex (P=0.047) but not with depression, the genotypes of 5-HTTLPR and BDNF Val66Met, the current antidepressant treatment, or the duration under hemodialysis.
  
  
  CONCLUSIONS
  Our results did not support the hypothesis of an involvement of the 5HTTLPR and BDNF Val66Met genotypes, or plasma BDNF levels in the pathogenesis of depression, in patients receiving hemodialysis. A study with a large sample size and homogenous patient group is warranted to confirm these findings.
authors.affiliation: Department of Child and Adolescent Psychiatry, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Liang-Jen
authors.initials: LJ
authors.lastname: Wang
authors.affiliation: Department of Psychiatry, Chang Gung Memorial Hospital, Keelung, Taiwan ; Chang Gung University School of Medicine, Taoyuan, Taiwan.
authors.forename: Chih-Ken
authors.initials: CK
authors.lastname: Chen
authors.affiliation: Chang Gung University School of Medicine, Taoyuan, Taiwan ; Department of Nephrology, Chang Gung Memorial Hospital, Keelung, Taiwan.
authors.forename: Heng-Jung
authors.initials: HJ
authors.lastname: Hsu
authors.affiliation: Chang Gung University School of Medicine, Taoyuan, Taiwan ; Department of Nephrology, Chang Gung Memorial Hospital, Keelung, Taiwan.
authors.forename: I-Wen
authors.initials: IW
authors.lastname: Wu
authors.affiliation: Chang Gung University School of Medicine, Taoyuan, Taiwan ; Department of Nephrology, Chang Gung Memorial Hospital, Keelung, Taiwan.
authors.forename: Chiao-Yin
authors.initials: CY
authors.lastname: Sun
authors.affiliation: Chang Gung University School of Medicine, Taoyuan, Taiwan ; Department of Nephrology, Chang Gung Memorial Hospital, Keelung, Taiwan.
authors.forename: Chin-Chan
authors.initials: CC
authors.lastname: Lee
keywords: BDNF; gene; hemodialysis; medical disease; mood disorder; serotonin