Ketamine-related neural changes in treatment-resistant depression: A multimodal synthesis of fMRI and PET studies.
Journal of affective disorders September 1, 2026 Nesreen Sedeek, Carley Rivers, Lucas Williamson et al.
Ketamine's rapid antidepressant effects in treatment-resistant depression are linked to changes in brain activity, but previous studies have been hard to compare due to differences in imaging techniques, analysis methods, and timing. A review combining fMRI and PET studies found that ketamine-related effects commonly appear in subcortical brain regions, with more variable effects in cortical areas like the prefrontal and anterior cingulate cortices. Network-level patterns suggest involvement of the default-mode, ventral attention, and visual systems. These findings are hypothesis-generating and highlight the need for future studies that harmonize methods to directly connect circuit changes to molecular mechanisms and clinical outcomes.