title: Serum Brain-derived neurotrophic factor (BDNF): the severity and symptomatic dimensions of depression.
abstract: BACKGROUND
  The aim of this study was to compare the concentration of serum Brain-derived neurotrophic factor (BDNF) in patients suffering from major depressive disorder (MDD) considering the severity of MDD episode defined by the Hamilton rating scale for depression (HAMD-17). The other aim was to research the connection between serum BDNF and the symptomatic dimensions of MDD.
  
  
  METHODS
  The study includes 139 participants with major depressive disorder (MDD). Diagnosis of MDD was set by DSM-IV-TR criteria. The severity of MDD was estimated with HAM-D-17 in the manner that mild episode was diagnosed if the score on HAMD-17 was up to 18, moderately severe 18-25 and severe over 25. Concentration of BDNF was determined by the ELISA method.
  
  
  RESULTS
  This research could not find a difference in BDNF concentration considering the severity of the depressive disorder in groups suffering from mild, moderately severe and severe episodes of MDD (F=1.816; p=0.169). Factor analysis of HAMD-17 extracted four dimensions of depressive symptoms. None of the symptomatic dimensions was significantly related to BDNF concentration.
  
  
  CONCLUSIONS
  Results of this study indicate that serum BDNF levels are not related to the severity of depression and its specific symptomatic dimensions. These findings support the idea of a complex relationship between BDNF concentration at the periphery and in the CNS.
authors.affiliation: Clinic for Psychological Medicine, University of Zagreb Medical School, Kišpatićeva 12, 10000 Zagreb, Croatia. sasa.jevtovic@zg.t-com.hr
authors.forename: Saša
authors.initials: S
authors.lastname: Jevtović
authors.forename: Dalibor
authors.initials: D
authors.lastname: Karlović
authors.forename: Alma
authors.initials: A
authors.lastname: Mihaljević-Peleš
authors.forename: Vesna
authors.initials: V
authors.lastname: Šerić
authors.forename: Nada
authors.initials: N
authors.lastname: Vrkić
authors.forename: Nenad
authors.initials: N
authors.lastname: Jakšić
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D003865:Major Depressive Disorder / Q000097:blood* / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010555:Personality Inventory / Q000706:statistics & numerical data; D011594:Psychometrics
chemical_list: D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor