After six low-dose esketamine infusions, patients with treatment-resistant depression showed improvement in anhedonia and depressive symptoms. Plasma levels of cortisol, interleukin-6, and tumor necrosis factor-alpha decreased, while the anti-inflammatory cytokine interleukin-4 increased. Baseline cortisol levels correlated with anhedonia, but inflammatory factors showed no significant correlation. Elevated plasma cortisol may serve as a potential biomarker for anhedonia in treatment-resistant depression.
In patients with depression, six intravenous infusions of esketamine (0.4 mg/kg) over 11 days significantly reduced depressive symptoms, with mean Montgomery-Asberg Depression Rating Scale scores dropping from 32.11 to 15.10. Memory function—including immediate memory, language, attention, and delayed memory—improved, and plasma nerve growth factor (NGF) levels rose from 226.13 to 384.37 pg/mL. A positive correlation existed between baseline memory function and NGF levels, while higher baseline memory was linked to smaller NGF increases. These findings suggest NGF may contribute to esketamine's memory-enhancing effects, though the open-label design limits certainty.