title: A test of the stress-buffering model of social support in smoking cessation: is the relationship between social support and time to relapse mediated by reduced withdrawal symptoms?
abstract: BACKGROUND
  Social support has been linked to quitting smoking, but the mechanisms by which social support affects cessation are poorly understood. The current study tested a stress-buffering model of social support, which posits that social support protects or "buffers" individuals from stress related to quitting smoking. We hypothesized that social support would be negatively associated with risk of relapse, and that this effect would be mediated by reduced withdrawal and depressive symptoms (i.e., cessation-related stress) over time. Further, we predicted that trait neuroticism would moderate this mediational effect, such that individuals high in negative affectivity would show the greatest stress-buffering effects of social support.
  
  
  METHODS
  Participants were weight-concerned women (n = 349) ages 18-65 enrolled in a randomized, double-blind, placebo-controlled smoking cessation trial of bupropion and cognitive behavioral therapy. Social support was assessed at baseline, and biochemically-verified abstinence, withdrawal-related symptoms, and depressive symptoms were assessed at 1-, 3-, 6-, and 12-months follow-up.
  
  
  RESULTS
  Social support was negatively related to risk of relapse in survival models and negatively related to withdrawal symptoms and depression in mixed effects models. These relationships held after controlling for the effects of pre-quit day negative affect and depression symptoms, assignment to treatment condition, and number of cigarettes smoked per day. A temporal mediation model showed that the effect of social support on risk of relapse was mediated by reductions in withdrawal symptoms over time but not by depression over time. Contrary to hypotheses, we did not find that neuroticism moderated this mediation effect.
  
  
  CONCLUSIONS
  Increased social support may buffer women from the harmful effects of cessation-related withdrawal symptoms, which in turn improve cessation outcomes.
authors.affiliation: Department of Psychology, Carnegie Mellon University, Pittsburgh, PA; kasey@andrew.cmu.edu.
authors.forename: Kasey G
authors.initials: KG
authors.lastname: Creswell
authors.affiliation: Department of Statistics, University of Pittsburgh, Pittsburgh, PA; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Michele D
authors.initials: MD
authors.lastname: Levine
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016642:Bupropion / Q000627:therapeutic use; D002908:Chronic Disease; D015928:Cognitive Behavioral Therapy / Q000379:methods; D003376:Counseling; D003863:Depression / Q000150:complications / Q000628:therapy; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008875:Middle Aged; D012008:Recurrence; D012907:Smoking / Q000523:psychology; D016540:Smoking Cessation / Q000379:methods* / Q000523:psychology; D012944:Social Support; D013315:Stress, Psychological; D013375:Substance Withdrawal Syndrome / Q000188:drug therapy / Q000628:therapy; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D016642:Bupropion