Cerebellar alterations in cannabis users: A systematic review

Area of Science:

• Neuroscience
• Psychiatry
• Addiction Research

Background:

• Cannabis is the world's most frequently used illicit substance.
• Cerebellum's role in cognition, emotion, learning, and addiction is increasingly recognized.
• High CB1 receptor density in the cerebellum suggests significant cannabis impact.

Purpose of the Study:

• To systematically review how cannabis use affects cerebellar structure and function.
• To examine impacts on cerebellar-dependent behavioral tasks.

Main Methods:

• Systematic review of peer-reviewed literature up to March 2018.
• Searched three databases for studies on cannabis effects on cerebellum structure, function, or behavior.
• Included 40 studies in qualitative synthesis after screening 348 records.

Main Results:

• Consistent findings include increased cerebellar gray matter volume with chronic use.
• Alterations in cerebellar resting-state activity observed after acute or chronic cannabis exposure.
• Deficits noted in memory, decision-making, and associative learning tasks.

Conclusions:

• Chronic cannabis use is linked to cerebellar structural and functional changes.
• Behavioral deficits in tasks involving the cerebellum are associated with cannabis use.
• Age of onset and exposure levels correlate with cannabis-induced alterations.