Chronic use has been shown to lead to a decrease in the amount of gray matter in the ventromedial prefrontal cortex. The decrease in gray matter and effect on behavior is analogous to a person having lesions throughout their medial prefrontal cortex.
The long-term consequences of substance use can lead to a reduction in brain tissue in the ventromedial prefrontal area, which is comparable to the damage caused by lesions in the medial prefrontal region of the brain.