Nevertheless, average lifetime cigarette use is expected to contribute to anatomical and chemical changes in the brain (Franklin et al. 2014). Further, the phenotypic associations reported here are similar to others using cigarette pack-years in community-based samples of older adults (Chen et al. 2006; Das et al. 2012). Therefore, in the absence of measures of nicotine dependence, the use of cigarette pack-years holds promise for understanding the biological pathways underlying smoking-related behaviors.
