Several studies have reported entropy reductions in regions of the brain associated with affective-regulatory and reward- and motivation-related processes in patients with major depressive disorder. However, whether low-dose ketamine modulates this reduction remains unclear. We analyzed resting-state functional magnetic resonance imaging data from two single-infusion low-dose ketamine trials....
We examined symptom-level treatment effects and exploratory symptom networks after ketamine in treatment-resistant depression. This post hoc analysis pooled 132 participants assigned to ketamine 0.5 mg/kg or protocol-specific control (66 each) from saline-controlled 2017 and midazolam-controlled 2023 trials. Baseline- and trial-adjusted models assessed Montgomery-Åsberg Depression Rating Scale...
Background: Studies have demonstrated that subanesthetic-dose ketamine may modulate the functioning of specific depression-related brain regions, particularly the anterior cingulate cortex and prefrontal cortex. However, how subanesthetic-dose ketamine alters the global and regional graph theory metrics of resting-state functional connectivity in patients with treatment-resistant depression...
Emerging evidence shows that ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, can produce rapid anti-suicidal effects in treatment-resistant depression, yet its underlying neuropharmacological mechanisms remain elusive. The present study aimed at investigating the therapeutic effect of ketamine infusion on suicidal ideation by examining hemodynamic response changes in resting-state...
Intravenous ketamine demonstrates rapid efficacy for treatment-resistant depression (TRD). However, its impact on individual depressive symptoms and whether the degree of treatment resistance moderates these effects remain unclear. This study aimed to dissect symptom-specific trajectories and examine the moderating role of the degree of treatment resistance. We conducted a post-hoc analysis of...
As accumulating evidence suggests the antisuicidal properties of ketamine, elucidating its underlying mechanisms and predictors of treatment response has become crucial. Whether a combination of clinical markers can enhance the prediction of the antisuicidal response to ketamine remains unclear.Using data from our previous randomized placebo-controlled and open-label trials, this post hoc...
Occupational stress among psychiatric nurses has reached levels that threaten both workforce stability and patient care quality, yet evidence-based interventions targeting this population remain scarce in East Asian healthcare systems. This research evaluated the efficacy of an 8-week mindfulness-based stress reduction (MBSR) program adapted for psychiatric nursing staff at two psychiatric...
Evidence suggests the crucial role of dysfunctional default mode (DMN), salience and frontoparietal (FPN) networks, collectively termed the triple network model, in the pathophysiology of treatment-resistant depression (TRD). Using the graph theory- and seed-based functional connectivity analyses, we attempted to elucidate the role of low-dose ketamine in the triple networks, namely the DMN,...
Low-dose ketamine is an N-methyl-D-aspartate receptor antagonist that exerts an antidepressant effect on patients with treatment-resistant depression (TRD). This antidepressant effect may extend beyond the glutamatergic hypothesis. Nevertheless, the roles of genes encoding other monoamine neurotransmitters (i.e., serotonin and dopamine) in the neuromechanism of low-dose ketamine remain unknown....
Ketamine is a dissociative drug used for the treatment of depression. However, the neurofunctional mechanism underlying the antidepressant effect of ketamine remains unknown. According to previous research, low-dose ketamine affects large-scale brain networks, including default-mode and salient networks. A total of 43 patients with treatment-resistant depression (TRD) and suicidal ideation (SI)...
Abstract Background The role of neurofilament light chain (NFL) in treatment-resistant depression (TRD) is unclear. Whether baseline NFL concentrations are associated with the antidepressant effects of low- dose ketamine infusion has not been determined. Methods The NFL concentrations of 71 patients with TRD and 17 healthy controls were assessed. Patients with TRD were randomly administered a...
Previous studies have shown an association between the thalamocortical dysconnectivity and treatment-resistant depression (TRD). Whether a single subanesthetic dose of ketamine may change thalamocortical connectivity among patients with TRD is unclear. Whether these changes in thalamocortical connectivity is associated with the antidepressant and antisuicidal effects of ketamine treatment is...
Low-grade inflammation (LGI) contributes to resistance against traditional antidepressants. However, whether the antidepressant and antisuicidal effects of ketamine on patients with treatment-resistant depression (TRD) differ between those with LGI and those without LGI remains unknown.This study included 167 patients with TRD, among whom 46 had LGI and 121 did not have LGI. The patients...
Background: Low-dose ketamine infusion has been demonstrated to exert antisuicidal effects on patients with treatment-resistant depression (TRD) and strong suicidal ideation. Although evidence suggests an association between hopelessness and suicidality, very few studies have investigated the antihopelessness effects of ketamine. Methods: This study included 84 patients with TRD and strong...
OBJECTIVE Previous studies have found an association between klotho, an anti-aging hormone, and major depressive disorder. However, whether low-dose ketamine infusion alters klotho levels among patients with treatment-resistant depression (TRD) remains unknown. METHODS In total, 48 patients with TRD and strong suicidal ideation were randomly assigned to a single 0.5 mg/kg ketamine or 0.045...
Whether pretreatment working memory and response inhibition function are associated with the rapid and sustained antisuicidal effect of low-dose ketamine among patients with treatment-resistant depression (TRD) and strong suicidal ideation is unclear. We enrolled 65 patients with TRD, comprising 33 who received a single infusion of 0.5 mg/kg ketamine and 32 who received a placebo infusion. The...
BACKGROUND Evidence indicates that vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) influence the pathophysiology of depression. However, whether low-dose ketamine regulates VEGF and MMP-9 levels and whether changes in VEGF and MMP-9 levels are associated with the antidepressant and antisuicidal effects of ketamine remained unclear. METHODS Forty-eight patients...
Abstract Background The benefits of low-dose ketamine for patients with treatment-resistant depression (TRD) and prominent suicidal ideation require further investigation. The effects of treatment refractoriness, the duration of the current depressive episode, and the number of prior antidepressant failures on ketamine efficacy also require clarification. Methods We recruited 84 outpatients...
BACKGROUND Whether cortical excitation and inhibition functions differ between patients with treatment-resistant depression (TRD) and strong suicidal ideation (SI) and healthy subjects and whether 0.5 mg/kg ketamine infusion can modulate cortical excitation and inhibition functions among patients with TRD-SI remain unclear. METHODS A total of 29 patients with TRD-SI and 35 age- and sex-matched...
BACKGROUND This posthoc analysis compared the antidepressant and antisuicidal effects of low-dose ketamine infusion with those of repetitive transcranial magnetic stimulation (rTMS) on treatment-resistant depression (TRD). METHODS In the ketamine infusion trial, 48 patients with TRD were randomized to receive a single infusion of 0.5 mg/kg ketamine or normal saline. In the rTMS trial, 105...
AbstractBackgroundThe antidepressant effect of low-dose ketamine infusion on Taiwanese patients with anxious vs nonanxious treatment-resistant depression (ANX-TRD vs NANX-TRD) has remained unknown.MethodsIn total, 71 patients with TRD were randomized to three groups. Each group had participants who received saline infusions mixed with 0 (a normal saline infusion), 0.2, and 0.5 mg/kg of...
Frontostriatal disconnectivity plays a crucial role in the pathophysiology of major depressive disorder. However, whether the baseline functional connectivity of the frontostriatal network could predict the treatment outcome of low-dose ketamine infusion remains unknown. In total, 48 patients with treatment-resistant depression were randomly divided into 3 treatment groups (a single-dose...
Increasing evidence suggests that infusion of a subanesthetic dose of ketamine exerts antidepressant and antisuicidal effects in patients with treatment-resistant depression (TRD). In this investigation, we used the resting functional connectivity magnetic resonance imaging (fcMRI) to determine the effects of ketamine on the functional connectivity (FC) of prefrontal cortex (PFC)-related...
Clinical and animal studies have reported conflicting results regarding the effect of ketamine on cognitive function, although increasing evidence supports a rapid and sustained antidepressant effect of a subanesthetic dose of ketamine infusion for patients with treatment-resistant depression (TRD). However, the cognitive function before and after ketamine infusion was rarely investigated in...
Increasing evidence supports the rapid antidepressant effect of a low-dose ketamine infusion in treatment-resistant depression (TRD). Proinflammatory cytokines play a crucial role in the pathophysiology of TRD. However, it is unknown whether the rapid antidepressant effect of ketamine is related to the rapid suppression of proinflammatory cytokines. Seventy-one patients with TRD were randomized...