Neural complexity EEG biomarkers of rapid and post-rapid ketamine effects in late-life treatment-resistant depression: a randomized control trial
Neuropsychopharmacology April 19, 2023 N. Murphy, Amanda J. F. Tamman, Marijn Lijffijt et al. 18 citations
A single low-dose infusion of ketamine in older military veterans with treatment-resistant depression temporarily increases the brain's neural complexity, measured by electroencephalogram (EEG) markers Lempel-Ziv complexity and multiscale entropy, within 30 minutes after infusion. These effects vary over time, with some complexity measures decreasing later. However, these changes in complexity were not linked to reductions in depressive symptoms after seven days. The findings suggest that ketamine produces broad, time-varying effects on brain dynamics beyond previously studied gamma oscillations, offering a potential non-linear marker of the drug's action.