title: Effects of smoking on the acoustic startle response and prepulse inhibition in smokers with and without posttraumatic stress disorder.
abstract: BACKGROUND
  Cigarette smokers smoke in part because nicotine helps regulate attention. Prepulse inhibition (PPI) of the startle reflex is a measure of early attentional gating that is reduced in abstinent smokers and in groups with attention regulation difficulties. Attention difficulties are found in people with posttraumatic stress disorder (PTSD).
  
  
  OBJECTIVE
  The aim of this study is to assess whether smoking and abstinence differentially affect the startle response and PPI in smokers with and without PTSD.
  
  
  METHODS
  Startle response and PPI (prepulses at 60, 120, or 240 ms) were measured in smokers with (N = 39) and without (N = 61) PTSD, while smoking and again while abstinent.
  
  
  RESULTS
  Participants with PTSD produced both larger magnitude and faster latency startle responses than controls. Across groups, PPI was greater when smoking than when abstinent. The PTSD and control group exhibited different patterns of PPI across prepulse intervals when smoking and when abstinent. Older age was associated with reduced PPI, but only when abstinent from smoking.
  
  
  CONCLUSIONS
  The effects of PTSD on startle magnitude and of smoking on PPI replicate earlier studies. The different pattern of PPI exhibited in PTSD and control groups across prepulse intervals, while smoking and abstinent suggests that previous research on smoking and PPI has been limited by not including longer prepulse intervals, and that nicotine may affect the time course as well as increasing the level of PPI. The reduced PPI among older participants during abstinence suggests that nicotine may play a role in maintaining attention in older smokers, which may motivate continued smoking in older individuals.
authors.affiliation: Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Vrana
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Calhoun
authors.forename: F Joseph
authors.initials: FJ
authors.lastname: McClernon
authors.forename: Michelle F
authors.initials: MF
authors.lastname: Dennis
authors.forename: Sherman T
authors.initials: ST
authors.lastname: Lee
authors.forename: Jean C
authors.initials: JC
authors.lastname: Beckham
mesh_terms: D000328:Adult; D000367:Age Factors; D001288:Attention / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000008:administration & dosage*; D013216:Reflex, Startle / Q000187:drug effects*; D012907:Smoking / Q000523:psychology*; D013313:Stress Disorders, Post-Traumatic / Q000503:physiopathology*
chemical_list: D009538:Nicotine