LONG-TERM MARIJUANA USE CHANGES BRAIN'S REWARD CIRCUIT

Researchers have demonstrated that long-term marijuana users had more activity in the brain's reward processes when presented with cannabis cues than with natural reward cues.

This study shows that marijuana disrupts the natural reward circuitry of the brain, making marijuana highly salient to those who use it heavily. In essence, these brain alterations could be a marker of transition from recreational marijuana use to problematic use.

Researchers studied 59 adult marijuana users and 70 nonusers, accounting for potential biases such as traumatic brain injury and other drug use. On average, marijuana participants had used the drug for 12 years. Study participants rated their urge to use marijuana after looking at various visual cannabis cues, such as a pipe, bong, joint or blunt, and self-selected images of preferred fruit, such as a banana, an apple, grapes or an orange.

When presented with marijuana cues compared to fruit, marijuana users showed enhanced response in the brain regions associated with reward, such as the orbitofrontal cortex, striatum, anterior cingulate gyrus, precuneus and the ventral tegmental area.

Thanks to: sciencedaily.com