OverviewThe brain effects of marijuana use is a rapidly increasing area of neuroscience. This study specifically addressed changes in brain volume using MRI. The brain scans of marijuana users were compared to those of nonusers to determine any differences in response to the substance use. The results demonstrated that marijuana users had decreased orbitofrontal gyri volume bilaterally (frontal lobe), and increased functional and structural connectivity in the orbitofrontal cortex (OFC) network, a brain region rich in cannabis receptors. Additionally, more differences were found among marijuana users themselves, with those individuals who started using cannabis at a younger age having higher, more increased functional activity in the OFC network than those with a more recent age of onset. As this study is just the beginning of identifying brain changes following marijuana use, follow-up longitudinal studies would be necessary to determine a causal relationship between marijuana and these observed effects.
Cannabis users showed higher resting brain activity in the frontal and temporal areas compared with nonusers.