Ketamine's rapid antidepressant effects are linked to enhanced neuroplasticity in the amygdala and hippocampus, brain regions involved in fear and learning. Anxiety during ketamine infusion is associated with poorer treatment outcomes. In a single-blind, placebo-controlled study, 17 healthy volunteers received placebo then 0.5 mg/kg ketamine intravenously. Anxiety was measured using the 5D-ASC score, and brain scans were taken 4 hours after infusion. Smaller hippocampal head volume significantly predicted greater anxiety (β = -0.733, p = 0.006), with similar trends for subfields. Hippocampal subfield volumes may help predict anxiety-related experiences during ketamine use and potentially treatment outcomes.
Ketamine, a drug used for treatment-resistant depression, may offer benefits for negative and depressive symptoms in schizophrenia, though no randomized controlled trials have tested it in psychotic disorders. Negative symptoms like apathy and anhedonia are hard to treat and often overlap with depression. Case reports show ketamine can improve mood without triggering psychosis, and its dissociative effects usually fade within one to two hours. This review examines ketamine's potential advantages and risks for schizophrenia patients, focusing on negative and depressive symptoms.