Journal of Clinical Psychiatry
September 22, 2025
Robert C. Meisner, Shuang Li, Brian W. Boyle et al.
5 citations
In patients with severe treatment-resistant depression, intravenous racemic ketamine produced a faster and larger reduction in depressive symptoms than intranasal esketamine. Over eight treatment sessions, those receiving IV ketamine showed a 49.22% decrease in depression scores, compared to a 39.55% decrease with intranasal esketamine. The IV group showed significant improvement after just one treatment, while the intranasal group required two treatments. Both treatments were effective, but IV ketamine was associated with greater overall efficacy and more rapid response.
Biological psychiatry global open science
July 1, 2025
Shuang Li, Anhang Jiang, Xuefeng Ma et al.
3 citations
Internet gaming disorder (IGD) is a global mental health issue, and effective treatments remain challenging. In a study of 61 participants with IGD, 30 received mindfulness meditation (MM) training and 31 received progressive muscle relaxation (PMR) over eight sessions. Using resting-state functional MRI and dynamic network analysis of 142 brain regions, MM training significantly reduced addiction severity and cravings compared to PMR, which showed only nonspecific effects. MM increased brain network recruitment in the frontoparietal and basal ganglia networks while decreasing it in the default mode network, and increased integration between the frontoparietal-default mode and default mode-limbic networks. MM may improve top-down control, cognitive and emotional functions, and reward processing through reconfiguration of these neural pathways.
Biological psychiatry global open science
May 1, 2026
Mario Bogdanov, Jason N Scott, Shiba M Esfand et al.
1 citation
A single low dose of ketamine improves the ability to learn from rewards in both people with treatment-resistant depression and stressed rats, using nearly identical tasks. Twenty-four hours after receiving ketamine, individuals with treatment-resistant depression and chronically stressed rats showed a stronger tendency to choose the more frequently rewarded option, matching the performance of healthy controls. This effect was most pronounced in people with more severe anhedonia at the start. Ketamine did not affect general task accuracy, indicating it selectively boosts reward learning rather than overall performance. These findings point to a shared behavioral mechanism by which ketamine alleviates anhedonia, with potential implications for treating anhedonia in depression and related conditions.
medRxiv Preprint Server
June 2, 2025
Mario Bogdanov, Jason N. Scott, Shiba M. Esfand et al.
1 citation
preprint
A single, subanesthetic dose of ketamine improved reward responsiveness in both humans with treatment-resistant depression and chronically-stressed rats, measured using functionally identical tasks. The finding suggests that ketamine's rapid antidepressant effects may involve enhancing reward processing, a core feature of anhedonia. The work provides translational evidence linking preclinical and clinical observations, though the mechanisms remain unclear.
Translational psychiatry
March 6, 2026
Ty Lees, Jason N Scott, Brian W Boyle et al.
A single low dose of ketamine (0.5 mg/kg) reduced depressive, anhedonic, and ruminative symptoms 24 hours later in 24 people with treatment-resistant depression. The symptom improvement was not linked to changes in brain connectivity but was associated with connectivity patterns present before the infusion. After ketamine, participants showed broad increases in resting-state functional connectivity within and between the default mode and frontoparietal networks, as measured by EEG. The authors suggest these connectivity increases may reflect ketamine's synaptogenic effects, which can be short-lived. The study included 34 healthy controls who did not receive ketamine.