title: No Association between the Response to the Addition of an Atypical Antipsychotic Drug to an SSRI or SNRI and the BDNF (Val66Met) Polymorphism in Refractory Major Depressive Disorder in Japanese Patients.
abstract: OBJECTIVE
  This study examined the association between the brain-derived neurotrophic factor (BDNF) (Val66Met) polymorphism and the response to the addition of an atypical antipsychotic drug to a selective serotonin reuptake inhibitor (SSRI) or serotonin-norepinephrine reuptake inhibitor (SNRI) in treatment-refractory depression.
  
  
  METHODS
  The study enrolled 64 patients meeting the Diagnostic and Statistical Manual of Mental Disorders-IV criteria for major depressive disorder who were treated with at least two courses of a single antidepressant, but who had Hamilton Depression Rating Scale (HAMD-17) scores ≥15 points that were reduced less than 50% over at least a 4-week treatment period. There were 24 males and 40 females (age range 27-68 years; mean±SD, 48±13 years). The patients' clinical improvement was evaluated using the HAMD-17. Patients with at least a 50% decrease in the HAMD-17 score were defined as responders. Serum BDNF levels were assayed using enzyme-linked immunosorbent assays and the presence of the BDNF (Val66Met) polymorphism was determined using the TaqMan genotyping assay.
  
  
  RESULTS
  No correlation was found between the BDNF (Val66Met) polymorphism and a positive response to adding an atypical antipsychotic drug. No differences were observed in the changes in the serum BDNF levels and HAMD-17 scores between Val66Val and Met-carriers. In addition, in patients who experienced remission, the atypical antipsychotic drug was discontinued after at least 3 months of treatment and the patients were then followed for 1 year; 14 of 27 patients (52%) relapsed within 1 year.
  
  
  CONCLUSIONS
  These results suggest that the BDNF (Val66Met) polymorphism is not associated with the response to the augmentation of a SSRI or SNRI with an atypical antipsychotic drug, and that the combination of an atypical antipsychotic drug and a SSRI or SNRI should be continued for 3 months or more in refractory depressed patients in the Japanese population.
authors: Department of Psychiatry, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors: Reiji
authors: R
authors: Yoshimura
authors: Taro
authors: T
authors: Kishi
authors: Hikaru
authors: H
authors: Hori
authors: Atsuko
authors: A
authors: Ikenouchi-Sugita
authors: Wakako
authors: W
authors: Umene-Nakano
authors: Asuka
authors: A
authors: Katsuki
authors: Kenji
authors: K
authors: Hayashi
authors: Nakao
authors: N
authors: Iwata
authors: Jun
authors: J
authors: Nakamura
keywords: Antipsychotic drug; Brain-derived neurotrophic factor; Polymorphism; Selective Serotonin Reuptake Inhibitor; Serotonin Norepinephrine Reuptake Inhibitor; Treatment-resistant depressive disorder