Abnormal gray matter volume and resting-state functional connectivity in former heroin-dependent individuals abstinent for multiple years

• Published in: Addiction biology Vol. 21; no. 3; pp. 646 - 656
• Main Authors: Wang, Lubin, Zou, Feng, Zhai, Tianye, Lei, Yu, Tan, Shuwen, Jin, Xiao, Ye, Enmao, Shao, Yongcong, Yang, Yihong, Yang, Zheng
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.05.2016; John Wiley & Sons, Inc
• Subjects: Addictions; Adult; Brain mapping; Case-Control Studies; Cortex (parietal); Drug abuse; Female; Functional anatomy; Functional connectivity; Functional magnetic resonance imaging; Functional Neuroimaging; Gray Matter - diagnostic imaging; Gray Matter - physiopathology; gray matter volume; Heroin; heroin addiction; Heroin Dependence - diagnostic imaging; Heroin Dependence - physiopathology; Humans; Impulsive Behavior; impulsivity; Magnetic Resonance Imaging; Male; Middle Aged; Morphometry; multi-year abstinence; Neural networks; Neural Pathways - physiopathology; Neuroimaging; Occipital Lobe - diagnostic imaging; Occipital Lobe - physiopathology; Organ Size; Parietal Lobe - diagnostic imaging; Parietal Lobe - physiopathology; Parieto-occipital sulcus; Structure-function relationships; Substantia grisea; Young Adult; Functional connectivity; gray matter volume; impulsivity; heroin addiction; multi-year abstinence
• ISSN: 1355-6215; 1369-1600; 1369-1600
• DOI: 10.1111/adb.12228

Previous studies have suggested that heroin addiction is associated with structural and functional brain abnormalities. However, it is largely unknown whether these characteristics of brain abnormalities would be persistent or restored after long periods of abstinence. Considering the very high rates of relapse, we hypothesized that there may exist some latent neural vulnerabilities in abstinent heroin users. In this study, structural and resting‐state functional magnetic resonance imaging data were collected from 30 former heroin‐dependent (FHD) subjects who were drug free for more than 3 years and 30 non‐addicted control (CN) volunteers. Voxel‐based morphometry was used to identify possible gray matter volume differences between the FHD and CN groups. Alterations in resting‐state functional connectivity in FHD were examined using brain areas with gray matter deficits as seed regions. Significantly reduced gray matter volume was observed in FHD in an area surrounding the parieto‐occipital sulcus, which included the precuneus and cuneus. Functional connectivity analyses revealed that the FHD subjects showed reduced positive correlation within the default mode network and visual network and decreased negative correlation between the default mode network, visual network and task positive network. Moreover, the altered functional connectivity was correlated with self‐reported impulsivity scores in the FHD subjects. Our findings suggest that disruption of large‐scale brain systems is present in former heroin users even after multi‐year abstinence, which could serve as system‐level neural underpinnings for behavioral dysfunctions associated with addiction.