Ketamine's Antidepressant Mechanism Unveiled by Yokohama City University

A groundbreaking study led by Professor Takuya Takahashi from Yokohama City University, published in Molecular Psychiatry on March 5, 2026, has unveiled the molecular mechanism behind Ketamine's rapid antidepressant effects in patients with treatment-resistant depression (TRD). Using an innovative PET tracer, [¹¹C]K-2, the team directly visualized changes in AMPAR density in the living human brain. The study, involving 34 TRD patients and 49 healthy controls in Japan, revealed that Ketamine's clinical improvement is associated with dynamic, region-specific modulation of AMPAR, with increases in cortical regions and decreases in reward-related areas like the habenula. These findings provide direct human evidence supporting AMPAR modulation as a central mechanism and highlight AMPAR PET imaging as a promising biomarker for predicting treatment response, addressing a critical unmet need in mental healthcare and accelerating the development of personalized therapies for TRD.