Characteristics of White Matter Integrity During Different Phases of Abstinence in Heroin Use Disorders: A Diffusion Tensor Imaging Study.

OBJECTIVES

The recovery of heroin-induced white matter impairment during abstinence has been reported, determining the characteristics of this recovery can help to improve the therapeutic strategies. In this study, we explored white matter characteristics in heroin use disorders during different phases of abstinence by using a quantitative diffusion tensor imaging method.

METHODS

Seventeen and 22 male patients with long- and short-term abstinence (LA and SA, respectively) from heroin use and 20 male healthy controls participated in this study. Voxel-wise diffusion tensor imaging method was used for the comparison of fractional anisotropy (FA). Radial diffusivity (RD) and axial diffusivity (AD) were induced to explore the pathological characteristics of FA. The correlation between diffusion tensor indices and duration of abstinence was further analyzed.

RESULTS

Compared to the healthy controls, patients with SA had significantly reduced FA in extensive white matter regions, while those with LA had only 2 clusters that showed reduced FA, which were located mainly in the genu of the corpus callosum, forceps minor, uncinate fasciculus, left inferior fronto-occipital fasciculus, superior longitudinal fasciculus, and posterior thalamic radiation. Significantly increased RD with unchanged axial diffusivity were detected. FA in the regions with the significant intergroup difference between SA and LA correlated positively with the duration of abstinence. The RD in these regions correlated negatively with the duration of abstinence.

CONCLUSIONS

The findings suggested that the time-dependent recovery of white matter, especially the restoration of the myelin sheath, occurred in patients with LA. Longer-abstinent duration with strategies of enhancing myelination may improve treatment effectiveness.