title: Does smoking reduction worsen mental health? A comparison of two observational approaches.
abstract: OBJECTIVE
  The association between smoking reduction and mental health is of particular interest given that many smokers report that smoking offers mental health benefits. We aimed to assess the association between smoking reduction and change in mental health using two different analytical approaches to determine if there was any evidence of an association. There were no prior hypotheses.
  
  
  METHODS
  A secondary analysis of prospective individual level patient data from 5 merged placebo-controlled randomised trials of nicotine replacement therapy for smoking reduction.
  
  
  METHODS
  All participants were adult smokers, selected because they wanted to reduce but not stop smoking, and had smoked for at least 3 years. Participants were excluded if they were pregnant, breastfeeding, under psychiatric care, deemed to be unfit by a general practitioner, or part of a cessation programme. 2066 participants were enrolled in the trials, 177 participants were biologically validated as prolonged reducers, and 509 as continuing smokers at both 6-week and 18-week follow-ups.
  
  
  METHODS
  Change in mental health from baseline to an 18-week follow-up was measured using the emotional well-being subscale on the Short Form Health Survey-36.
  
  
  RESULTS
  After adjustment for confounding variables, the differences for reducers compared with continuing smokers were: regression modelling -0.6 (95% CI -4.4 to 3.2) and propensity score matching 1.1 (95% CI -2.0 to 4.1).
  
  
  CONCLUSIONS
  Smoking reduction, sustained for at least 12 weeks, was not associated with change in mental health, suggesting that reducing smoking was no better or worse for mental health than continuing smoking. Clinicians offering smoking reduction as a route to quit can be confident that, on average, smoking reduction is not associated with negative change in mental health.
authors.affiliation: Primary Care Clinical Sciences, School of Health & Population Sciences, University of Birmingham, Birmingham, UK UK Centre for Tobacco and Alcohol Studies, UK.
authors.forename: Gemma
authors.initials: G
authors.lastname: Taylor
authors.affiliation: UK Centre for Tobacco and Alcohol Studies, UK MRC Integrative Epidemiology Unit (IEU), University of Bristol, Bristol, UK School of Experimental Psychology, University of Bristol, Bristol, UK.
authors.forename: Amy
authors.initials: A
authors.lastname: Taylor
authors.affiliation: UK Centre for Tobacco and Alcohol Studies, UK MRC Integrative Epidemiology Unit (IEU), University of Bristol, Bristol, UK School of Experimental Psychology, University of Bristol, Bristol, UK.
authors.forename: Marcus R
authors.initials: MR
authors.lastname: Munafò
authors.affiliation: UK Centre for Tobacco and Alcohol Studies, UK Institute of Psychiatry, King's College London, London, UK.
authors.forename: Ann
authors.initials: A
authors.lastname: McNeill
authors.affiliation: UK Centre for Tobacco and Alcohol Studies, UK Nuffield Department of Primary Care Health Sciences, The University of Oxford, Oxford, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Aveyard
mesh_terms: D000328:Adult; D004644:Emotions; D005260:Female; D006801:Humans; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D019964:Mood Disorders / Q000209:etiology; D009538:Nicotine / Q000627:therapeutic use; D018722:Nicotinic Agonists / Q000627:therapeutic use; D011446:Prospective Studies; D012107:Research Design; D012907:Smoking / Q000009:adverse effects / Q000188:drug therapy; D016540:Smoking Cessation / Q000379:methods; D013375:Substance Withdrawal Syndrome / Q000209:etiology; D014029:Tobacco Use Disorder / Q000150:complications; D014026:Nicotiana
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine
keywords: MENTAL HEALTH; Smoking Reduction; Tobacco