Cannabis use and glutamate across the psychosis spectrum: in vivo evidence from 7T proton magnetic resonance spectroscopy
Molecular Psychiatry June 27, 2026 David R. Roalf, Tyler M. Moore, Jacquelyn Stifelman et al.
Cannabis use is linked to higher psychosis risk, and this study examined whether brain glutamate levels in the anterior cingulate cortex (ACC) relate to symptoms depending on cannabis use. Among 79 participants across the psychosis spectrum, higher ACC glutamate independently predicted greater positive and negative symptoms. However, in cannabis users, lower glutamate was associated with more positive symptoms. Psychosis patients who used cannabis had lower ACC glutamate, suggesting glutamatergic dysfunction may amplify symptom severity. The findings implicate ACC glutamate as a transdiagnostic correlate of symptom burden, especially in cannabis users with psychosis.