Canada’s six-year-old cannabis legalization has led to ongoing research into its long-term health effects. A new study published in JAMA Psychiatry found biological evidence linking frequent cannabis use to changes in brain chemistry resembling early psychosis.
The study, led by Canadian researchers, used advanced brain scans to observe elevated dopamine activity in people with cannabis use disorder (CUD). This increase occurred in areas previously linked to hallucinations, delusions, and other symptoms of psychotic disorders. The findings mark a turning point in understanding cannabis’ psychiatric risks, bridging the gap between clinical symptoms and underlying brain activity.
Researchers used neuromelanin-sensitive magnetic resonance imaging (MRI) to visualize dopamine activity indirectly by tracking neuromelanin, a vital compound in the brain. They found that participants with CUD had consistently higher neuromelanin signals across multiple scans, even when accounting for nicotine use and other variables.
The study’s lead author, Lena Palaniyappan, stated that increased dopamine functioning may be associated with the risk of psychosis in people with cannabis use disorder. The absence of a “recovery effect” raises new questions: Can these changes be reversed with abstinence? Do they set the stage for future psychiatric illness?
The study emphasizes that cannabis alone does not cause psychosis in every user, but it raises the risk, especially in those with family histories or early symptoms. By linking cannabis use to measurable brain changes, this study helps move the discussion from speculation to science.
Cannabis use disorder is increasingly linked to real, visible changes in the brain’s dopamine system that may shape vulnerability to psychosis. The findings could lead to more informed decisions and safer outcomes for clinicians, families, and users themselves.
Source: https://www.earth.com/news/dopamine-changes-from-cannabis-last-at-least-one-year