Changes in brain gray matter in abstinent heroin addicts

Background: Previous neuroimaging studies have documented changes in the brain of heroin addicts. However, few researches have detailed whether such changes can be amended after short-term abstinence. Methods: We used magnetic resonance imaging (MRI) to investigate gray matter volume in 20 heroin-dependent patients at 3 days and at 1 month after heroin abstinence; 20 normal subjects were also included as controls. Results: Decreased gray matter density in frontal cortex, cingulate and the occipital regions were found in heroin users after three days of abstinence. In contrast, after 1-month abstinence, no significant difference was found in superior frontal gyrus between heroin addicts and controls, but changes in other brain regions, including right middle frontal gyrus, left cingulate gyrus and left inferior occipital gyrus, still remained. Conclusion: Our findings illustrate that abnormal gray matter in some brain regions of heroin addicts can return to normal after one-month abstinence. (C) 2012 Elsevier Ireland Ltd. All rights reserved.