Human Brain Mapping
January 30, 2023
B. Taraku, R. Woods, Michael Boucher et al.
23 citations
In treatment-resistant depression, four intravenous ketamine infusions (0.5 mg/kg) given over 2–3 days led to significant improvements in depression and anhedonia scores. Brain scans revealed decreased neurite density in occipitotemporal white matter pathways after treatment. Greater reductions in anhedonia correlated with decreased neurite density in the left internal capsule and left superior longitudinal fasciculus. No significant changes were seen in other white matter measures. The neurite orientation dispersion and density imaging model may detect ketamine-induced white matter changes more sensitively than standard diffusion tensor imaging.
Journal of Affective Disorders
April 1, 2023
A. Zavaliangos-Petropulu, S. Mcclintock, Jacqueline Khalil et al.
16 citations
Ketamine treatment improves cognitive function in people with treatment-resistant depression, and these improvements last at least five weeks. In a study of 66 patients receiving four ketamine infusions, significant gains occurred in inhibition, working memory, processing speed, and overall fluid cognition after the first and fourth infusions. Processing speed and overall fluid cognition remained improved at a five-week follow-up, even though depressive symptoms had largely returned to baseline by then. Baseline working memory and changes in inhibition were moderately linked to antidepressant response, but cognitive improvements were statistically independent of mood changes, suggesting ketamine acts on overlapping but distinct brain systems.
Frontiers in Psychiatry
October 9, 2023
A. Zavaliangos-Petropulu, Shawn M. Mcclintock, S. Joshi et al.
6 citations
In patients with treatment-resistant depression, smaller hippocampal subfield volumes (left CA4 and GC-ML-DG) were observed before ketamine treatment compared to healthy controls. Four ketamine infusions over two weeks did not change hippocampal subfield volumes, and pre-treatment volumes did not predict improvement in depressive symptoms. However, smaller pre-treatment left CA4 and GC-ML-DG volumes were associated with greater improvement in processing speed after ketamine, and larger right CA3 volume was linked to better working memory at follow-up. Baseline hippocampal subfield volumes may serve as biomarkers for cognitive, but not antidepressant, response to ketamine.