title: Nicotine dependence and serum BDNF levels in male patients with schizophrenia.
abstract: OBJECTIVE
  Schizophrenia is associated with a significantly high prevalence of smoking. Upregulation of neurotrophins by nicotine is well established. Accumulating evidence shows that brain-derived neurotrophic factor (BDNF) may be involved in the pathophysiology of schizophrenia. The purposes of this study were to compare BDNF levels in smokers to nonsmokers with schizophrenia and examine the association between BDNF levels and psychopathological symptoms.
  
  
  METHODS
  Serum BDNF levels were measured in 139 male inpatients with DSM-IV schizophrenia: 102 smokers and 37 nonsmokers. Symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS).
  
  
  RESULTS
  The positive PANSS symptoms were lower in smokers than in nonsmokers, while the negative symptoms were lower in those who smoked more cigarettes. BDNF levels were significantly higher in smokers than in nonsmokers (p < 0.05). Higher BDNF levels correlated with fewer negative symptoms and with smoking more cigarettes.
  
  
  CONCLUSIONS
  The fewer positive symptoms in smokers and fewer negative symptoms in those who smoked more cigarettes may be associated with nicotine-induced upregulation of BDNF.
authors.affiliation: Center for Biological Psychiatry, Beijing HuiLongGuan Hospital, Beijing, 100096, China. xyzhang@bcm.edu
authors.forename: Xiang Yang
authors.initials: XY
authors.lastname: Zhang
authors.forename: Mei Hong
authors.initials: MH
authors.lastname: Xiu
authors.forename: Da Chun
authors.initials: DC
authors.lastname: Chen
authors.forename: Fu De
authors.initials: FD
authors.lastname: Yang
authors.forename: Gui Ying
authors.initials: GY
authors.lastname: Wu
authors.forename: Lin
authors.initials: L
authors.lastname: Lu
authors.forename: Therese A
authors.initials: TA
authors.lastname: Kosten
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Kosten
mesh_terms: D000328:Adult; D000368:Aged; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000150:complications / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012907:Smoking / Q000097:blood* / Q000453:epidemiology; D014029:Tobacco Use Disorder / Q000097:blood* / Q000453:epidemiology; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D019208:Brain-Derived Neurotrophic Factor