Long-term effects of marijuana use on the brain

Long-term effects of marijuana use on the brain:
"Abstract:
Questions surrounding the effects of chronic marijuana use on brain structure continue to increase.
To date, however, findings remain inconclusive.
In this comprehensive study that aimed to characterize brain alterations associated with chronic marijuana use, we measured gray matter (GM) volume via structural MRI across the whole brain by using voxel-based morphology, synchrony among abnormal GM regions during resting state via functional connectivity MRI, and white matter integrity (i.e., structural connectivity) between the abnormal GM regions via diffusion tensor imaging in 48 marijuana users and 62 age- and sex-matched nonusing controls.
The results showed that compared with controls, marijuana users had significantly less bilateral orbitofrontal gyri volume, higher functional connectivity in the orbitofrontal cortex (OFC) network, and higher structural connectivity in tracts that innervate the OFC (forceps minor) as measured by fractional anisotropy (FA).
Increased OFC functional connectivity in marijuana users was associated with earlier age of onset..."