title: White matter development and tobacco smoking in young adults: A systematic review with recommendations for future research.
abstract: BACKGROUND
  Adolescence and young adulthood are critical vulnerability periods for initiation of tobacco smoking. White matter development is ongoing during this time and may be influenced by exposure to nicotine. Synthesis of findings from diffusion tensor imaging (DTI) studies of adolescent and young adult smokers may be helpful in understanding the relationship between neurodevelopment and initiation and progression of tobacco-use behaviors and in guiding further research.
  
  
  METHODS
  A systematic literature review was conducted to identify DTI studies comparing adolescent and young adult (mean age <30 years) smokers versus nonsmokers. A total of 5 studies meeting inclusion criteria were identified. Primary study findings are reviewed and discussed within the context of neurodevelopment and in relation to findings from adult studies. Directions for further research are also discussed.
  
  
  RESULTS
  All identified studies reported increases in fractional anisotropy (FA) among adolescent/young adult smokers in comparison to non-smokers. Increased FA was most frequently reported in regions of the corpus callosum (genu, body and spenium), internal capsule and superior longitudinal fasciculus.
  
  
  CONCLUSIONS
  Findings of increased FA among adolescent/young adult smokers are contrary to those from most adult studies and thus raise the possibility of differential effects of nicotine on white matter across the lifespan. Further research including multiple time points is needed to test this hypothesis. Other areas warranting further research include DTI studies of e-cigarette use and studies incorporating measures of pubertal stage.
authors.affiliation: Bates College, Lewiston, ME, United States.
authors.forename: Alex R
authors.initials: AR
authors.lastname: Gogliettino
authors.affiliation: Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States; CASAColumbia, Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States; Connecticut Mental Health Center, New Haven, CT, United States; Department of Neurobiology, Yale University School of Medicine, New Haven, CT, United States; Yale Child Study Center, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Marc N
authors.initials: MN
authors.lastname: Potenza
authors.affiliation: Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States; CASAColumbia, Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States. Electronic address: sarah.yip@yale.edu.
authors.forename: Sarah W
authors.initials: SW
authors.lastname: Yip
mesh_terms: D016880:Anisotropy; D056324:Diffusion Tensor Imaging; D066300:Electronic Nicotine Delivery Systems / Q000009:adverse effects*; D006801:Humans; D059906:Neuroimaging; D009538:Nicotine / Q000009:adverse effects; D012907:Smoking / Q000009:adverse effects*; D066127:White Matter / Q000187:drug effects* / Q000254:growth & development*
chemical_list: D009538:Nicotine
keywords: Addiction; Adolescence; Development; Diffusion magnetic resonance imaging (dMRI); Nicotine dependence; White matter