Abnormalities and Plasticity of White Matter Functional Networks in Opioid Use Disorder: A BOLD fMRI Study

This study investigated the organization and neural activity of white matter functional networks (WMFNs) in individuals with opioid use disorder (OUD) before and after detoxification, compared with healthy controls (HC). Using a data-driven k-means clustering approach, we analyzed BOLD signals in the white matter of baseline OUD (OUD1), follow-up OUD after 8 months of detoxification (OUD2), and HC groups. Results revealed that OUD1 exhibited eight distinct WMFNs, while OUD2 and HC showed six and seven WMFNs, respectively. Notably, the deep frontoparietal network in OUD1 was fragmented into the superior longitudinal fasciculus and anterior corona radiata networks but partially recovered in OUD2, resembling HC. Additionally, OUD1 displayed hyperactivation in the deep frontal network and hypoactivation in the frontotemporal parietal network, with the latter negatively correlated with years of opioid use (r = -0.306, p = 0.039). These findings suggest that OUD disrupts white matter functional connectivity, while prolonged abstinence promotes partial network restoration, highlighting the brain’s neuroplastic potential. This study provides novel insights into the neural mechanisms of OUD and recovery, supporting the development of targeted rehabilitation strategies.