Brain dopamine release reduced in severe marijuana dependence

NIDA-funded research using brain scans shows that severe marijuana dependence (now referred to as cannabis use disorder) is associated with a reduced release of dopamine within the striatum, a region involved in working memory, impulsivity and attention. Lower dopamine release within the striatum was associated with greater emotional withdrawal and inattention in marijuana-dependent participants.

Most drugs of abuse lead to a general blunting of dopamine release which contributes to poor outcomes. These results are similar to those found with other behavioral health disorders, suggesting a similar mechanism underlying these deficits across conditions. The reduction in dopamine release for marijuana-dependent participants, compared to those who were not dependent, was not due to major psychiatric illnesses, or to the use of other drugs, since participants with these characteristics were excluded from the study.

For a copy of the abstract, “Deficits in striatal dopamine release in cannabis dependence,” co-authored by NIDA Director Dr. Nora Volkow and published in Molecular Psychiatry, go to www.nature.com/mp/journal/vaop/ncurrent/abs/mp201621a.html.

For more information about marijuana and marijuana use disorder, go to: https://www.drugabuse.gov/publications/research-reports/marijuana/what-marijuana

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