Altered gray matter volume and disrupted functional connectivity of dorsolateral prefrontal cortex in men with heroin...

Chronic heroin use can cause various neuropathological characteristics that may compromise brain function. The present study evaluated the alteration of gray matter volume (GMV) and its resting-state functional connectivity (rsFC) over the dorsolateral prefrontal cortex (DLPFC) among male heroin users.

Thirty heroin-dependent men undergoing methadone maintenance therapy and 30 educational-level- and age-matched male controls were recruited for this study. To assess their GMV and rsFC, the participants were evaluated using spoiled gradient echo and gradient-recalled echo planar imaging sequences with a 3-Tesla General Electric MR scanner under resting state.

The heroin-dependent men showed lower GMV over the right DLPFC in comparison with the controls. Further evaluation of the rsFC of the right DLPFC revealed a marked decrease in interhemispheric DLPFC connectivity among those with heroin dependence under control of head movement and GMV of the right DLPFC.

Although the mechanism remains unclear, the present study shows that chronic heroin use is associated with alteration of morphology as well as rsFC over the right DLPFC. As the DLPFC plays an imperative role in various domains of cognitive function, service providers for heroin users should consider the impacts of possible DLPFC-related cognitive deficits on treatment effectiveness.