Concurrent assessment of neurometabolism and brain hemodynamics to characterize the functional brain response to psychotropic drugs: An S-ketamine study.
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism April 1, 2026 Daphne E Boucherie, Liesbeth Reneman, Jan Booij et al.
A new method combining two brain imaging techniques—pharmacological MRI and pharmacological MRS—was tested in 32 healthy adults given S-ketamine or placebo. S-ketamine caused strong blood-flow changes in frontal, cingulate, and insular brain regions, which matched patterns of glutamate and opioid receptors and correlated with participants' reports of dissociation. These blood-flow changes occurred alongside increases in brain glutamate and lactate, especially at higher doses. Combining both imaging methods improved the ability to predict whether a person had received placebo, a low dose, or a high dose of S-ketamine. The findings show that simultaneously measuring blood flow and brain chemistry provides complementary insights into how drugs affect the brain.