title: A Systematic Review of Loneliness and Smoking: Small Effects, Big Implications.
abstract: BACKGROUND
  Research supports an association between smoking and negative affect. Loneliness is a negative affective state experienced when a person perceives themselves as socially isolated and is associated with poor health behaviors and increased morbidity and early mortality.
  
  
  OBJECTIVE
  In this article, we systematically review the literature on loneliness and smoking and suggest potential theoretical and methodological implications.
  
  
  METHODS
  PubMed and PsycINFO were systematically searched for articles that assessed the statistical association between loneliness and smoking. Articles that met study inclusion criteria were reviewed.
  
  
  RESULTS
  Twenty-five studies met inclusion criteria. Ten studies were conducted with nationally representative samples. Twelve studies assessed loneliness using a version of the UCLA Loneliness Scale and nine used a one-item measure of loneliness. Seventeen studies assessed smoking with a binary smoking status variable. Fourteen of the studies were conducted with adults and 11 with adolescents. Half of the reviewed studies reported a statistically significant association between loneliness and smoking. Of the studies with significant results, all but one study found that higher loneliness scores were associated with being a smoker.
  
  
  CONCLUSIONS
  Loneliness and smoking are likely associated, however, half of the studies reviewed did not report significant associations. Studies conducted with larger sample sizes, such as those that used nationally representative samples, were more likely to have statistically significant findings. Future studies should focus on using large, longitudinal cohorts, using measures that capture different aspects of loneliness and smoking, and exploring mediators and moderators of the association between loneliness and smoking.
authors.affiliation: a Keck School of Medicine , University of Southern California , Los Angeles , California , USA.
authors.forename: Stephanie R
authors.initials: SR
authors.lastname: Dyal
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Valente
mesh_terms: D000339:Affect; D005260:Female; D015438:Health Behavior; D006801:Humans; D008132:Loneliness / Q000523:psychology*; D008297:Male; D012737:Sex Factors; D012907:Smoking / Q000523:psychology*; D012934:Social Isolation / Q000523:psychology
keywords: cigarette; loneliness; smoking; tobacco