title: Effects of cigarette smoking and alcohol use on neurocognition and BDNF levels in a Chinese population.
abstract: OBJECTIVE
  Few studies have examined the potential interactive effect of both smoking and drinking on cognition. Brain-derived neurotrophic factor (BDNF) plays a critical role in cognition. This is the first study to examine the neurocognitive consequences of cigarette smoking combined with chronic alcohol consumption and their relationship to serum BDNF levels in a Chinese Han population.
  
  
  METHODS
  We recruited 191 healthy male subjects, including 47 isolated smokers, 31 isolated chronic alcohol users, 58 combined smokers and chronic alcohol users, and 55 non-smokers and non-alcohol users. We then compared the repeatable battery for the assessment of neuropsychological status (RBANS) scores and serum BDNF levels in these four groups.
  
  
  RESULTS
  When compared to the non-smoking + non-alcohol-using group, the smoking group performed worse on immediate memory, attention, language, and RBANS total score. There were no significant differences in the RBANS scores between the alcohol-using group and non-smoking + non-alcohol-using group, or between the smoking group and smoking + alcohol-using group. We did not find an association between BDNF and smoking or drinking status or between BDNF and cognitive performance. In the smoking group, there was a significant correlation between BDNF and carbon monoxide concentration, and between BDNF and the Fagerstrom Test for Nicotine Dependence (FTND) total score.
  
  
  CONCLUSIONS
  Our results suggest that smoking is associated with cognitive decline, but not with BDNF levels in a normal population. However, smoking severity is positively associated with BDNF levels. Concomitant alcohol use does not worsen the cognitive decline caused by smoking.
authors.affiliation: Beijing HuiLongGuan Hospital, Peking University, Beijing, China. zhangxy9@gmail.com.|Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA. zhangxy9@gmail.com.|UT Center of Excellence on Mood Disorders (UTCEMD), Biomedical and Behavioral Sciences Building, 1941 East Road, Houston, TX, 77054, USA. zhangxy9@gmail.com.
authors.forename: Xiang Yang
authors.initials: XY
authors.lastname: Zhang
authors.affiliation: Beijing HuiLongGuan Hospital, Peking University, Beijing, China.
authors.forename: Yun-Long
authors.initials: YL
authors.lastname: Tan
authors.affiliation: Beijing HuiLongGuan Hospital, Peking University, Beijing, China.
authors.forename: Da-Chun
authors.initials: DC
authors.lastname: Chen
authors.affiliation: Beijing HuiLongGuan Hospital, Peking University, Beijing, China.
authors.forename: Shu-Ping
authors.initials: SP
authors.lastname: Tan
authors.affiliation: Beijing HuiLongGuan Hospital, Peking University, Beijing, China.
authors.forename: Fu-De
authors.initials: FD
authors.lastname: Yang
authors.affiliation: Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: Giovana B
authors.initials: GB
authors.lastname: Zunta-Soares
authors.affiliation: Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: Jair C
authors.initials: JC
authors.lastname: Soares
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000378:metabolism* / Q000523:psychology*; D044466:Asian People; D001288:Attention / Q000187:drug effects; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D002248:Carbon Monoxide / Q000097:blood; D002681:China; D003071:Cognition / Q000187:drug effects*; D006801:Humans; D007802:Language; D008297:Male; D008568:Memory / Q000187:drug effects; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000187:drug effects; D012907:Smoking / Q000378:metabolism* / Q000523:psychology*; D014029:Tobacco Use Disorder / Q000523:psychology; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human; D002248:Carbon Monoxide
keywords: Alcohol; Brain-derived neurotrophic factor; Cognition; Nicotine; Smoking