Altered Topological Properties of White-Matter Functional Networks in Young Smokers

Smoking addiction is a common mental disorder, and numerous imaging studies have shown that adolescents with smoking addiction exhibit abnormalities in brain function and structure. This study aims to investigate changes in the topological characteristics of the white matter (WM) functional network in young smokers. Forty-two young smokers and 42 age-, gender-, and education-matched nonsmokers were included in the study. The functional connectome of white matter and graph theory were used to study these participants. Two-sample t-test were used for the detection of the abnormal graph properties in young smokers. Pearson correlation was applied for the correlation analyses between properties and clinical indicators of smoking. The global level WM functional network analyses showed that the $C_p$ and $E_{\text{local}}$ values were higher in young smokers than in the control group, and the $E_{\text{local}}$ was positively correlated with the age of first smoking. At the node level, five nodes of the WM functional network exhibited abnormal node properties in the WM regions of the bilateral hippocampal parahippocampal gyrus (CGH), bilateral superior longitudinal fasciculus (SLF), bilateral inferior frontal gyrus (IFO), middle cerebellar peduncle (MCP), and the bilateral anterior commissure (ACR) in young smokers. The node degree centrality value of MCP was positively correlated with age of first smoking. Our neuroimaging findings provide evidence of WM functional alterations associated with nicotine addiction, which may enhance our understanding of the neural mechanisms underlying smoking addiction in young smokers.