OPEN Foundation

W. Liu

Investigation of medical effect of multiple ketamine infusions on patients with major depressive disorder

Abstract

OBJECTIVE::

Single-dose intravenous ketamine has rapid but time-limited antidepressant effects. We aimed to examine the sustained effects of six consecutive ketamine infusions in Chinese patients with major depressive disorder.

METHODS::

Seventy-seven patients with major depressive disorder were eligible to receive augmentation with six ketamine infusions (0.5 mg/kg over 40 min) administered over the course of 12 days (Monday-Wednesday-Friday). The coprimary outcome measures were the rates of response and remission as measured on the 10-item Montgomery-Asberg Depression Rating Scale. Psychotomimetic and dissociative symptoms were measured with the Brief Psychiatric Rating Scale-positive symptoms and the Clinician Administered Dissociative States Scale, respectively.

RESULTS::

After the first ketamine infusion, only 10 (13.0%) and 6 (7.8%) patients responded and remitted, respectively; after six ketamine infusions, 52 (67.5%) patients responded and 37 (48.1%) remitted. There was a significant mean decrease in Montgomery-Asberg Depression Rating Scale score at four hours after the first ketamine infusion (7.0±7.5, p<0.001), and this decrease was maintained for the duration of the infusion period. The response to ketamine treatment was positively associated with no history of psychiatric hospitalization (odds ratio=3.56, p=0.009). Suicidal ideation rapidly decreased across the entire study sample, even among the nonresponder group. No significant differences were found regarding Brief Psychiatric Rating Scale and Clinician Administered Dissociative States Scale scores from the first infusion at baseline to four hours post-infusion.

CONCLUSION::

Six ketamine infusions increased rates of response and remission when compared to a single-dose ketamine infusion in patients with major depressive disorder. Future controlled studies are warranted to confirm and expand these findings.

Zheng, W., Zhou, Y. L., Liu, W. J., Wang, C. Y., Zhan, Y. N., Li, H. Q., … & Ning, Y. P. (2019). Investigation of medical effect of multiple ketamine infusions on patients with major depressive disorder. Journal of Psychopharmacology, 0269881119827811., 10.1177/0269881119827811
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Neurocognitive effects of six ketamine infusions and the association with antidepressant response in patients with unipolar and bipolar depression

Abstract

BACKGROUND:

Ketamine has proven to have rapid, robust antidepressant effects on treatment-resistant depression. However, whether repeated ketamine infusions would cause short-and long-term neurocognitive impairments was not clear. Our aims were to investigate the neurocognitive effects of six ketamine infusions and to examine the association between these infusions and the antidepressant response in patients with unipolar and bipolar depression.

METHODS:

Six intravenous infusions of ketamine (0.5 mg/kg) over a 12-day period were administered to 84 patients with unipolar and bipolar depression. Severity of depressive symptoms and four domains of neurocognition, including speed of processing, working memory, visual learning and verbal learning, were assessed at baseline, one day following the last infusion and again two weeks post-infusion.

RESULTS:

Significant improvements were found on speed of processing ( F=9.344, p<0.001) and verbal learning ( F=5.647, p=0.004) in a linear mixed model. The Sobel test showed significant indirect effects between time and improvement in speed of processing (Sobel test=3.573, p<0.001) as well as improvement in verbal learning (Sobel test=6.649, p<0.001), which were both significantly mediated by change in depressive symptoms. Logistic regression analysis showed ketamine responders had better visual learning at baseline than non-responders (B=0.118, p<0.001).

CONCLUSIONS:

Our findings suggest that neurocognitive function would not deteriorate after six ketamine infusions, while verbal learning and speed of processing improved over 13 days and 26 days of observation, respectively. However, this change was mainly accounted for by improvements in severity of depressive symptoms over time. Greater baseline visual learning predicted an antidepressant response over six ketamine infusions.

Zhou, Y., Zheng, W., Liu, W., Wang, C., Zhan, Y., Li, H., … & Ning, Y. (2018). Neurocognitive effects of six ketamine infusions and the association with antidepressant response in patients with unipolar and bipolar depression. Journal of Psychopharmacology32(10), 1118-1126, 10.1177/0269881118798614
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