Clinical Case Reports
December 1, 2022
Adem T. Can, Daniel F. Hermens, Jim Lagopoulos
6 citations
A single patient with severe treatment-resistant depression received maintenance therapy with very low-dose subcutaneous ketamine, following initial improvement with intravenous ketamine. A retrospective chart review showed that this approach sustained the antidepressant response without significant side effects, suggesting a potential alternative maintenance strategy for patients who respond to intravenous ketamine but require ongoing treatment.
European Archives of Psychiatry and Clinical Neuroscience
May 21, 2024
Zack Y Shan, Adem T. Can, Abdalla Z Mohamed et al.
3 citations
Ketamine treatment for chronic suicidality alters how brain networks synchronize and transition over time. In a 6-week open-label trial with 29 patients, those who received ketamine showed significantly more transitions among whole-brain connectivity states after treatment. At a 10-week follow-up, patients spent more time in and more frequently visited a highly synchronized brain state, and these changes correlated with reduced suicidal ideation scores. Patients who persistently responded to ketamine had a higher baseline fraction of a cognitive control network state with strong connections, suggesting that pre-treatment brain connectivity patterns may help predict who will benefit from ketamine therapy. These findings point to a biological mechanism for ketamine's suicide-prevention effects.
medRxiv Preprint Server
November 26, 2024
Bonnie L. Quigley, Adem T. Can, Megan Dutton et al.
1 citation
preprint
A weekly low-dose oral ketamine treatment for six weeks significantly reduced PTSD symptoms in adults with PTSD, many of whom also had depression. PTSD Checklist scores dropped from an average of 40 before treatment to 17 after treatment, and remained reduced at 21 one month later. 73% of participants showed at least a 50% reduction in symptoms after treatment, and 59% maintained that improvement at follow-up. The results suggest oral ketamine is a feasible and tolerable treatment option, comparable to intravenous ketamine, and may overcome limitations of IV administration.
medRxiv Preprint Server
March 2, 2025
Bonnie L. Quigley, Emerald Orr, Sophie Kafka et al.
preprint
In a 6-week open-label trial of low-dose oral ketamine for PTSD, blood samples from 25 participants showed a small but significant decrease in both BDNF and VEGF-A levels after treatment, with a positive correlation between the two biomarkers. This suggests ketamine's effects may involve a reciprocal interaction between BDNF and VEGF-A, offering potential insight into a biological mechanism for PTSD symptom reduction. Novel relationships between FKBP51, serotonin, and clinical scales were also observed. No significant changes in immune cytokines were detected, possibly because half the participants had low-grade inflammation and half did not.
Brain and Behavior
November 1, 2024
Jules S Mitchell, Toomas E Anijärv, Adem T. Can et al.
Subanesthetic doses of ketamine show promise for treating suicidality, but predictive biomarkers are lacking. This study examined EEG-derived complexity measures—Lempel-Ziv complexity (LZC) and multiscale entropy (MSE)—in 31 participants receiving six weekly oral doses of racemic ketamine (0.5-3 mg/kg). Responders, defined by a ≥50% reduction in Beck Suicide Scale score or a score ≤6, showed elevated baseline eyes-open complexity compared to nonresponders, which decreased from baseline to post-treatment. Elevated baseline eyes-open LZC in responders was localized to the left frontal lobe. EEG complexity metrics may serve as sensitive biomarkers for predicting and evaluating oral ketamine treatment response.