title: Serum brain-derived neurotrophic factor level in relation to illness severity and episode duration in patients with major depression.
abstract: BACKGROUND
  Since there are few data on the possible association between BDNF levels and characteristics of major depression, the present study assesses brain-derived neurotrophic factor (BDNF) levels in three drug-free patient samples, and explores whether episode duration, and severity correlate with serum BDNF levels.
  
  
  METHODS
  Serum BDNF levels were measured in 42 drug-free patients with major depression. The duration of the index episode and the presence of psychotic features were assessed with the Schedule for Affective Disorders and Schizophrenia, and the severity of depression was measured with the 17-item Hamilton Rating Scale for Depression. The sample was divided into three groups: severely depressed inpatients without psychotic features, severely depressed inpatients with psychotic features, and moderately depressed outpatients.
  
  
  RESULTS
  Mean serum BDNF level in the total sample was 18.0 ± 2.8 ng/ml, with no significant difference between the three patient samples (F = 1.80, df = 2, p = 0.18). Mean serum BDNF level was significantly lower in patients with an index episode over one year, compared with patients who had a shorter index episode (F = 4.90, df = 1, p = 0.033).
  
  
  CONCLUSIONS
  These data show that patients with a long index episode have significantly lower serum BDNF levels. We found no influence of the presence of psychotic features and severity of depression on serum BDNF levels.
authors.affiliation: Department of Psychiatry, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. t.birkenhager@erasmusmc.nl
authors.forename: Tom K
authors.initials: TK
authors.lastname: Birkenhäger
authors.forename: Sarah
authors.initials: S
authors.lastname: Geldermans
authors.forename: Walter W
authors.initials: WW
authors.lastname: Van den Broek
authors.forename: Nico
authors.initials: N
authors.lastname: van Beveren
authors.forename: Durk
authors.initials: D
authors.lastname: Fekkes
mesh_terms: D000328:Adult; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D003865:Major Depressive Disorder / Q000097:blood* / Q000150:complications / Q000175:diagnosis / Q000523:psychology; D017050:Episode of Care; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011581:Psychological Tests; D011618:Psychotic Disorders / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D012720:Severity of Illness Index
chemical_list: D019208:Brain-Derived Neurotrophic Factor