title: Is impulsivity a symptom of initial tobacco withdrawal? A meta-analysis and qualitative systematic review.
abstract: BACKGROUND
  We reviewed existing experimental studies of whether impulsivity is a symptom of tobacco withdrawal.
  
  
  METHODS
  We conducted searches of PubMed, PsychInfo and other sources to find experimental studies that measured self-reported impatience, delay discounting (DD), or response inhibition (RI) while smoking and during initial abstinence in untreated smokers. Two of the authors (JRH and MD) independently examined titles, then abstracts, and then articles to locate studies and to enter study characteristics. Major inclusion criteria were (a) adult daily smokers, (b) measured impulsivity before and after ≥13hr of abstinence, and (c) no pharmacological treatment provided.
  
  
  RESULTS
  We located 6 studies that examined self-reported impatience, 4 that examined DD, and 3 that examined RI. A meta-analysis was feasible only for the impatience studies. A random-effects meta-analysis found initial abstinence increased impatience by 0.44 points on 4-point scales (p = .0001). Importantly, 3 of the 4 impatience studies that examined the time course found a time-limited pattern consistent with a withdrawal effect. Qualitative review of the DD and RI studies found mixed results such that no conclusions could be made.
  
  
  CONCLUSIONS
  The number of studies on impulsivity and tobacco abstinence is surprisingly small. Self-reported impatience appears to be a tobacco withdrawal symptom but whether it is associated with functional changes in DD or RI is unclear. Further studies of whether abstinence produces objective changes in impulsivity, and whether increases in impulsivity during abstinence prompt relapse, are needed.
authors.affiliation: Department of Psychiatry, Psychology and Family Practice, University of Vermont, Burlington, VT; john.hughes@med.uvm.edu.
authors.forename: John R
authors.initials: JR
authors.lastname: Hughes
authors.affiliation: Department of Medical Biostatistics, University of Vermont, Burlington, VT.
authors.forename: Miriam
authors.initials: M
authors.lastname: Dash
authors.affiliation: Department of Medical Biostatistics, University of Vermont, Burlington, VT.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Callas
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007175:Impulsive Behavior; D008297:Male; D009538:Nicotine / Q000009:adverse effects; D012907:Smoking / Q000009:adverse effects*; D016540:Smoking Cessation; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*; D013997:Time Factors; D014029:Tobacco Use Disorder / Q000503:physiopathology*; D014026:Nicotiana
chemical_list: D009538:Nicotine