Efficacy of low-dose ketamine infusion in anxious vs nonanxious depression: revisiting the Adjunctive Ketamine Study of Taiwanese Patients with Treatment-Resistant Depression
Mu-Hong Chen, Wei-Chen Lin, Hui-Ju Wu, Ya-Mei Bai, Cheng-Ta Li, Shih-Jen Tsai, Chen-Jee Hong, Pei-Chi Tu, Chih-Ming Cheng, Tung-Ping Su
CNS Spectrums August 1, 2021 DOI: 10.1017/s1092852920001194 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Sample size | 71 |
| Population | Taiwanese patients with treatment-resistant depression, divided into anxious (ANX-TRD) and nonanxious (NANX-TRD) subtypes |
| Interventions | Ketamine saline |
| Dose | 0.2 and 0.5 mg/kg |
| Duration | 2-week follow-up |
| Measures | 17-item Hamilton Depression Rating Scale Anxiety-Somatization factor |
| Topics | Depression Esketamine Ketamine |
| Key findings | Low-dose ketamine infusion was superior to placebo for reducing depressive symptoms in nonanxious treatment-resistant depression but not in anxious treatment-resistant depression. Roughly 30% of anxious-depression patients responded to ketamine versus 13% to placebo, yet the authors report ketamine was not superior to placebo in this group and suggest higher anxiety severity may confound and reduce ketamine's antidepressant effect. |
Abstract
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 ketamine. Participants were followed up for 2 weeks. Anxious depression was defined as major depressive disorder with a total score of 7 or more on the 17-item Hamilton Depression Rating Scale Anxiety-Somatization factor. Generalized estimating equation models were used to investigate the effects of treatment (ketamine vs placebo) and depression type (ANX-TRD vs NANX-TRD) in the reduction of depressive symptoms during the follow-up period.ResultsPatients with ANX-TRD were less likely to respond to a single low-dose ketamine infusion than those with NANX-TRD. Among patients with NANX-TRD, low-dose ketamine infusion was significantly superior to placebo for reducing depressive symptoms. However, among patients with ANX-TRD, ketamine was not superior to placebo; nonetheless, approximately 30% of the patients responded to ketamine infusion compared to 13% who responded to the placebo.ConclusionsLow-dose ketamine infusion was effective for Taiwanese patients with NANX-TRD but not so effective for those with ANX-TRD. A higher level of anxiety severity accompanying depression was related to greater depression severity. This may confound and reduce the antidepressant effect of ketamine infusion.