# Strong Correlation Between Grey Matter Volume and Striatal Glutamate in Early Psychosis Cannabis Users > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/association-cannabis-glutamate-early-psychosis/ > **Published:** 2021-05-11T14:29:58-04:00 | **Last Modified / Clinically Audited:** 2026-09-28T12:02:19-04:00 > **Clinical Summary:** Explore the association cannabis glutamate early psychosis reveals altered brain volume and glutamate levels in patients with cannabis use history. --- ### Association of cannabis with glutamatergic levels in patients with early psychosis: Evidence for altered volume striatal glutamate relationships in patients with a history of cannabis use in early psychosis In Summary: ​Psychosis is a debilitating but quite common mental condition characterized by a disconnection from reality; therefore, multiple ongoing research efforts are dedicated to understanding the mechanism of this disorder. Glutamate is the most abundant excitatory neurotransmitter – chemicals that nerve cells use to send signals to other cells – in the brain and one of its main sites of action is a brain structure known as striatum. [Medical research](https://cedclinic.com/cb2-receptor-agonist-parkinsons/) has previously established that psychotic symptoms are related to abnormal glutamate transmission at the striatum. THC, the main psychoactive compound in cannabis, creates the sense of relaxation and euphoria through binding to and activating the [cannabinoid receptor type 1](https://cedclinic.com/mediation-of-the-cannabinoid-receptor-type-1-can-enhance-the-antidepressant-powers-of-conventional-therapy/) (CB1), which is very abundant in the brain, especially in the grey matter (neuronal cell body). Because there are widespread neural projections from grey matter regions with high CB1 expression to the striatum, it has been postulated that abnormal glutamate level and distribution pattern may underlie multiple symptoms experienced by patients with a dual diagnosis of psychosis and [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/). Recently, through a large clinical study with four groups: early psychosis patients with and without a history of [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/) and healthy individuals with and without a history of cannabis use, researchers have found evidence of a significant, unique correlation in early psychosis patients who used cannabis: the more grey matter volume, the higher striatal glutamate level. The causal relationship behind this correlation – whether a history of cannabis use leads to a change in connectivity of these brain regions or the native patterns of some patients’ brains predispose them to heavy cannabis use – remains to be further investigated. [More access here](https://cedclinic.com/) [https://cedclinic.com/contact/](https://cedclinic.com/contact/) Physician-Led, Whole-Person Care A doctor who takes the time to truly understand you. Personal care that starts with listening and is guided by experience and ingenuity. 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[Read More](https://cedclinic.com/cannabidiol-clinical-trials-psychosis-research/) [A Huge Study Finds a Link Between Cannabis Use in Teens and Psychosis Later – KUOW](https://cedclinic.com/adolescent-cannabis-exposure-psychosis-risk/) Explore findings on how [adolescent cannabis use](https://cedclinic.com/adolescent-cannabis-use-and-anxiety-research/) may increase psychosis risk, complementing glutamate and brain volume studies. [Explore Study](https://cedclinic.com/adolescent-cannabis-exposure-psychosis-risk/) [Cannabis and Psychosis: Cannabis Isn't Risk-Free](https://cedclinic.com/high-potency-cannabis-mental-health-risks/) Understand the risks of high-THC and frequent cannabis use on psychosis, providing context for glutamate and brain volume correlations. [Learn More](https://cedclinic.com/high-potency-cannabis-mental-health-risks/) Have thoughts on this? 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