title: Natural killer cell activity in patients with major depressive disorder treated with escitalopram.
abstract: BACKGROUND
  An association between depression and altered immunity has been suggested by many studies, although the findings are not fully consistent. The present investigation examined the effects of escitalopram on cellular immunity in patients with major depressive disorder (MDD).
  
  
  METHODS
  Fifty-one patients with MDD were evaluated with the Hamilton Rating Scale for Depression and Montgomery-Åsberg Depression Rating Scale. The patients were grouped into responders (n=32) and non-responders (n=19). Adrenocorticotropic hormone, cortisol, CD4, CD8, CD19, and natural killer cells were measured at baseline and after a 4 week treatment with escitalopram. Plasma hormones and immune parameters were compared between groups.
  
  
  RESULTS
  Responders showed increased activity, but not number, of natural killer cells after a 4 week treatment with escitalopram. There were no differences in plasma hormones and other immune parameters between groups, even though cortisol was decreased and CD19 was increased across both groups compared to baseline.
  
  
  CONCLUSIONS
  The results suggest that natural killer cells play an important role in improving the symptoms of depressive patients responding to selective serotonin inhibitors. To deepen our understanding of the pathogenesis of depression, interactions between serotonin and the immune system should be further explored.
authors.affiliation: Department of Psychiatry, College of Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: E-Jin
authors.initials: EJ
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine, College of Medicine, St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Je-Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Dea-Chul
authors.initials: DC
authors.lastname: Jeong
authors.affiliation: Department of Psychiatry, College of Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Sang-Ick
authors.initials: SI
authors.lastname: Han
authors.affiliation: Department of Psychiatry, College of Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: Jeonleo@olmh.cuk.ac.kr.
authors.forename: Yang-Whan
authors.initials: YW
authors.lastname: Jeon
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D018687:Antidepressive Agents, Second-Generation / Q000494:pharmacology* / Q000627:therapeutic use; D018941:Antigens, CD19 / Q000097:blood; D002470:Cell Survival / Q000187:drug effects; D015283:Citalopram / Q000494:pharmacology* / Q000627:therapeutic use; D003865:Major Depressive Disorder / Q000097:blood / Q000188:drug therapy / Q000276:immunology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000324:Adrenocorticotropic Hormone; D018687:Antidepressive Agents, Second-Generation; D018941:Antigens, CD19; D015283:Citalopram; D006854:Hydrocortisone; D017367:Selective Serotonin Reuptake Inhibitors
keywords: Activity; Depression; Escitalopram; Natural killer cell; SSRI