title: Cigarette smoking and thinning of the brain's cortex.
abstract: Cigarette smoking is associated with cognitive decline and dementia, but the extent of the association between smoking and structural brain changes remains unclear. Importantly, it is unknown whether smoking-related brain changes are reversible after smoking cessation. We analyzed data on 504 subjects with recall of lifetime smoking data and a structural brain magnetic resonance imaging at age 73 years from which measures of cortical thickness were extracted. Multiple regression analyses were performed controlling for gender and exact age at scanning. To determine dose-response relationships, the association between smoking pack-years and cortical thickness was tested and then repeated, while controlling for a comprehensive list of covariates including, among others, cognitive ability before starting smoking. Further, we tested associations between cortical thickness and number of years since last cigarette, while controlling for lifetime smoking. There was a diffuse dose-dependent negative association between smoking and cortical thickness. Some negative dose-dependent cortical associations persisted after controlling for all covariates. Accounting for total amount of lifetime smoking, the cortex of subjects who stopped smoking seems to have partially recovered for each year without smoking. However, it took ~25 years for complete cortical recovery in affected areas for those at the mean pack-years value in this sample. As the cortex thins with normal aging, our data suggest that smoking is associated with diffuse accelerated cortical thinning, a biomarker of cognitive decline in adults. Although partial recovery appears possible, it can be a long process.
authors: 1] Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada [2] Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Verdun, QC, Canada.
authors: S
authors: S
authors: Karama
authors: 1] Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada [2] Department of Psychiatry, McGill University Health Centre, Montreal, QC, Canada [3] Department of Psychiatry and Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA [4] Department of Neurology, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors: S
authors: S
authors: Ducharme
authors: Department of Psychology, University of Edinburgh, Edinburgh, UK.
authors: J
authors: J
authors: Corley
authors: Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
authors: F
authors: F
authors: Chouinard-Decorte
authors: 1] Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [2] Department of Psychology, Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK.
authors: J M
authors: JM
authors: Starr
authors: 1] Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [2] Department of Radiology, Division of Neuroimaging Sciences, Brain Research Imaging Centre, University of Edinburgh, Edinburgh, UK.
authors: J M
authors: JM
authors: Wardlaw
authors: 1] Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK [2] Department of Radiology, Division of Neuroimaging Sciences, Brain Research Imaging Centre, University of Edinburgh, Edinburgh, UK.
authors: M E
authors: ME
authors: Bastin
authors: 1] Department of Psychology, University of Edinburgh, Edinburgh, UK [2] Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK.
authors: I J
authors: IJ
authors: Deary
mesh_terms: D000368:Aged; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology*; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009538:Nicotine / Q000494:pharmacology; D012907:Smoking / Q000473:pathology* / Q000503:physiopathology
chemical_list: D009538:Nicotine