ABSTRACT
Objective To investigate the effects of different abstinent duration on brain functional network of heroin addicts at resting state.Methods Sixteen heroin addicts during protracted abstinence for 11-13 months (PA12 group) and twenty heroin addicts during protracted abstinence for 5-7 months (PA6 group) were recruited in the resting-state functional MRI study.Graph theoretical methods were applied to construct topological organization of whole brain network and nodes betweenness of the networks in all subjects,and the between-group differences were analyzed.The correlation of the node betweenness with the abstinence duration was conducted.Results There was no significant difference (P＞0.05) in the small world characteristic (γ≈1,λ》1) between two groups.Compared with the PA6 group,the PA12 group demonstrated significantly decreased nodal betweenness in regions of left parahippocampal gyrus,left precentral gyrus,and significantly enhanced nodal betweenness in regions of the left cuneus,left temporal and right middle occipital gyrus (all P＜0.05).Moreover,the betweenness of the left precentral gyrus (r =-0.52,P =0.001) and parahippocampal gyrus (r=-0.49,P=0.002) were negatively related with the abstinence duration,the betweenness of the right middle occipital was positively correlated with the abstinence duration (r=0.49,P=0.003).Conclusion The brain network small world topology of heroin addicts tend to be stable after 5-7 months of abstinence.Long-term abstinence may minimize the addicfs memory of drugs and potential drug seeking behavior,and recover addicts' visual spatial attention function.