Recent studies have shown that the administration of psilocybin may reduce depression severity. A role of glutamate was hypothesized in the antidepressant efficacy, however the exact neurobiological mechanisms remain unknown. Proton MR spectroscopy enables a valuable insight into glutamatergic metabolism and provides information about other important neuronal markers such as N-acetylaspartate. Here, we have utilized STEAM MR spectroscopy at 7T to observe the changes of cortical metabolites after psilocybin administration in patients with major depressive disorder. Two high dose sessions of psilocybin decreased glutamate and NAA levels of the anterior cingulate in the cohort.