biostudies-literatureUnknown79(11)Bottemanne H<h4>Importance</h4>Clinical research has shown that persistent negative beliefs maintain depression and that subanesthetic ketamine infusions induce rapid antidepressant responses.<h4>Objective</h4>To evaluate whether ketamine alters belief updating and how such cognitive effects are associated with the clinical effects of ketamine.<h4>Design, setting, and participants</h4>This study used an observational case-control protocol with a mixed-effects design that nested 2 groups by 2 testing time points. Observers were not blinded. Patients with treatment-resistant depression (TRD) and healthy volunteer participants aged 34 to 68 years were included. Patients with TRD were diagnosed with major depressive disorder or bipolar depression, had a Montgomery-Åsberg Depression Rating Scale score greaJAMA psychiatry1124-1132https://www.ebi.ac.uk/biostudies/studies/S-EPMC9520441biostudies-literatureEvaluation of Early Ketamine Effects on Belief-Updating Biases in Patients With Treatment-Resistant Depression.PMC9520441Claret AFossati PSchmidt LBottemanne HSharot TMorlaas OfalseEvaluation of Early Ketamine Effects on Belief-Updating Biases in Patients With Treatment-Resistant Depression.<h4>Importance</h4>Clinical research has shown that persistent negative beliefs maintain depression and that subanesthetic ketamine infusions induce rapid antidepressant responses.<h4>Objective</h4>To evaluate whether ketamine alters belief updating and how such cognitive effects are associated with the clinical effects of ketamine.<h4>Design, setting, and participants</h4>This study used an observational case-control protocol with a mixed-effects design that nested 2 groups by 2 testing time points. Observers were not blinded. Patients with treatment-resistant depression (TRD) and healthy volunteer participants aged 34 to 68 years were included. Patients with TRD were diagnosed with major depressive disorder or bipolar depression, had a Montgomery-Åsberg Depression Rating Scale score grea2022-01-01T00:00:00Z2022 Nov2025-04-18T20:40:06.987Z2025-04-07T08:44:35.414ZS-EPMC95204413616996910.1001/jamapsychiatry.2022.2996