Modulation of early non-rapid eye movement slow wave activity by ketamine in treatment-resistant depression.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology June 16, 2026 Nadia Hejazi, Mina Kheirkhah, Brady Riedner et al.
Slow-wave activity (SWA) during early non-rapid eye movement sleep is lower in people with treatment-resistant depression (TRD) than in healthy volunteers. Ketamine, but not placebo, increases SWA in TRD patients, especially those who respond to treatment, while having no effect on SWA in healthy volunteers. Ketamine also improves overall sleep in TRD patients by increasing total sleep time and sleep efficiency and reducing sleep latency. The increase in SWA after ketamine lessens with age. The findings suggest that ketamine's antidepressant effects are closely tied to its modulation of early sleep SWA and its ability to improve sleep architecture in TRD.