Functional Connectivity Disruptions in Grey Matter Volume-Altered Brain Regions Among Male Smokers: A Neuroimaging...

This study aimed to investigate whether structural brain alterations in smokers are accompanied by synchronized changes in functional connectivity, with a focus on understanding the neural mechanisms underlying smoking addiction. We conducted a meta-analysis of voxel-based morphometry (VBM) studies using the Seed Mapping software package to identify consistent grey matter changes in smokers' brains, which were subsequently defined as regions of interest (ROIs). Resting-state functional connectivity between these ROIs and whole-brain voxels was analysed in 53 male smokers and 38 non-smokers. Additional correlation analyses were performed to assess relationships with clinical features. Smokers exhibited reduced functional connectivity between the right lingual gyrus (which showed increased grey matter volume) and the left calcarine sulcus. The right superior frontal gyrus (with decreased grey matter volume) suggested diminished functional connectivity with multiple regions, including the bilateral precentral and postcentral gyrus, left rolandic operculum, left inferior frontal gyrus (opercular part), left midcingulate cortex, bilateral supplementary motor area, left paracentral lobule, right inferior frontal gyrus (triangular part) and right middle frontal gyrus (GRF corrected, voxel-level p < 0.001, cluster-level p < 0.05). Notably, reduced connectivity of some brain regions to the right superior frontal gyrus was negatively correlated with the Fagerström Test for Nicotine Dependence (FTND). Our findings demonstrate that structural brain alterations in smokers are associated with specific disruptions in functional connectivity, particularly within visual attention, executive control and sensorimotor networks. These results provide additional evidence of the neuropathophysiological mechanisms underlying smoking addiction.