title: Blunted vagal reactivity predicts stress-precipitated tobacco smoking.
abstract: BACKGROUND
  Long-term smoking can lead to changes in autonomic function, including decreased vagal tone and altered stress responses. One index of the inability to adapt to stress may be blunted vagal reactivity. Stress is a primary mechanism involved in relapse to smoking, but mechanisms leading to stress-precipitated relapse are not well understood.
  
  
  OBJECTIVE
  Using an experimental paradigm of stress-precipitated smoking behavior, we examined whether autonomic reactivity mediates the relationship between stress and smoking. High-frequency heart rate variability (HF-HRV), a putative measure of vagal tone, and the ratio of low-to-high frequency HRV (LF/HF), a measure of sympathovagal balance, were assessed.
  
  
  METHODS
  Using a within-subjects design, 32 nicotine-dependent, 15-h abstinent smokers (a subgroup from McKee et al. (J Psychopharmacol 25(4):490-502, 2011)) were exposed to individualized script-driven imagery of stressful and relaxing scenarios and assessed on the ability to resist smoking and subsequent ad-lib smoking. HRV was monitored throughout each laboratory session (maximum 60 min following imagery).
  
  
  RESULTS
  As expected, stress and ad-lib smoking additively decreased HF-HRV and increased LF/HF. Blunted stress-induced HF-HRV responses reflecting decreased vagal reactivity were associated with less time to initiate smoking and increased craving relief and reinforcement from smoking. These relationships were specific to HF-HRV following stress as neither baseline HF-HRV, HF-HRV following relaxing imagery, or LF/HF predicted smoking behavior.
  
  
  CONCLUSIONS
  The current findings are the first to experimentally demonstrate that stress-precipitated decreased vagal reactivity predicts the ability to resist smoking. Findings suggest that strategies that normalize vagal reactivity in early abstinent smokers may lead to improved smoking cessation outcomes.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, 2 Church St. South, Suite 109, New Haven, CT 06519, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Ashare
authors.forename: Rajita
authors.initials: R
authors.lastname: Sinha
authors.forename: Rachel
authors.initials: R
authors.lastname: Lampert
authors.forename: Andrea H
authors.initials: AH
authors.lastname: Weinberger
authors.forename: George M
authors.initials: GM
authors.lastname: Anderson
authors.forename: Meaghan E
authors.initials: ME
authors.lastname: Lavery
authors.forename: Katherine
authors.initials: K
authors.lastname: Yanagisawa
authors.forename: Sherry A
authors.initials: SA
authors.lastname: McKee
mesh_terms: D000293:Adolescent; D000328:Adult; D016739:Behavior, Addictive / Q000503:physiopathology / Q000523:psychology; D015716:Electrocardiography, Ambulatory / Q000379:methods / Q000523:psychology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D012907:Smoking / Q000503:physiopathology*; D013315:Stress, Psychological / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D014029:Tobacco Use Disorder / Q000503:physiopathology; D014630:Vagus Nerve / Q000502:physiology*