Ram mushroom (Maitake, Griflola frondosa) is a medicinal mushroom used for thousands of years. This study examines the antidepressant effects of this fungus and the role of AMPA receptors in the provision of this antidepressant effect. Mice were fed for 1 day or 5 days with a ram mushroom or oyster oyster as a control. The antidepressant effect was determined during the tail suspension test, the forced swimming test and the open field test. The involvement of AMPA receptors was determined by the use of a specific AMPA receptor blocker. Eating food containing lamb mushroom significantly reduced the time of immobility (an indicator of stress)  from 30.8 to 60.8%. The food containing the lamb mushroom did not cause hyperactivity during the tests. The antidepressant effect when eating food containing a ram mushroom was significantly stronger than when eating food containing oyster mushrooms. A specific blocker of AMPA receptors GYKI 52466 could block the antidepressant effect of eating food containing a lamb mushroom, which shows that the mechanism of action most likely involves these receptors.  Thus, the ram mushroom (maitake) has shown its promise as a safe medicinal food supplement for patients with depression.