title: Cerebrospinal fluid interleukin (IL)-6 in unipolar major depression.
abstract: BACKGROUND
  Previous studies have suggested that regulation of the proinflammatory cytokine interleukin (IL)-6 is abnormal in patients with major depression. This study was undertaken to determine whether IL-6 concentrations in cerebrospinal fluid (CSF) differ between depressed patients and healthy control subjects.
  
  
  METHODS
  Lumbar puncture with a standardized procedure was performed on 18 drug-free patients meeting DSM-IV criteria for unipolar major depression and 26 age- and sex-matched healthy volunteers. CSF was assayed for IL-6 using a quantitative 'sandwich' enzyme immunoassay technique.
  
  
  RESULTS
  Mean+/-S.D. CSF IL-6 levels did not differ between depressed (2.2+/-1.0 pg/ml) and healthy control (2.4+/-1.9 pg/ml) subjects.
  
  
  CONCLUSIONS
  This study had adequate power (0.8) to detect a large (d=0.88) effect size at alpha = 0.05. Although sample sizes were comparable to or larger than those of previous CSF studies, it is possible that a less robust difference between depressed and healthy subjects was not detected.
  
  
  CONCLUSIONS
  These findings fail to support speculation that immune activation may be causally involved in the pathogenesis of depression.
authors.affiliation: Mood Disorders Research Program, Butler Hospital, and Department of Psychiatry and Human Behavior, Brown Medical School, Providence, RI, USA. linda_carpenter_md@brown.edu
authors.forename: Linda L
authors.initials: LL
authors.lastname: Carpenter
authors.forename: George R
authors.initials: GR
authors.lastname: Heninger
authors.forename: Robert T
authors.initials: RT
authors.lastname: Malison
authors.forename: Audrey R
authors.initials: AR
authors.lastname: Tyrka
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Price
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D003866:Depressive Disorder / Q000276:immunology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D013129:Spinal Puncture
chemical_list: D015415:Biomarkers; D015850:Interleukin-6