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Comparative study of low-dose ketamine infusion and repetitive transcranial magnetic stimulation in treatment-resistant depression: A posthoc pooled analysis of two randomized, double-blind, placebo-controlled studies.

Mu-Hong Chen, Chih-Ming Cheng, Cheng-Ta Li, S. Tsai, Wei-Chen Lin, Ya-Mei Bai, T. Su

Psychiatry Research July 1, 2022 DOI: 10.1016/j.psychres.2022.114749 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Posthoc analysis of two randomized controlled trials Placebo-controlled Double-blind Peer reviewed
Sample size 153
Population Patients with treatment-resistant depression
Interventions Ketamine intermittent theta-burst stimulation (iTBS) 10-Hz rTMS sham stimulation normal saline
Dose 0.5 mg/kg ketamine
Duration Follow-up up to 3 months
Measures 17-item Hamilton Rating Scale for Depression (HDRS), HDRS item 3
Topics Depression Esketamine Ketamine
Key findings Low-dose ketamine infusion produced a prominent antidepressant effect at Day 7, while iTBS and 10-Hz rTMS effects accumulated from Day 7 to 14. Ketamine and iTBS were superior for suicidal symptoms. rTMS effects persisted up to 3 months, but a single ketamine infusion's effect did not last beyond one month. The authors contend both treatments should be included in treatment-resistant depression care, applied in different clinical situations.

Abstract

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 patients were randomly assigned to intermittent theta-burst stimulation (iTBS), 10-Hz rTMS, or sham stimulation. The 17-item Hamilton Rating Scale for Depression (HDRS) was administered.

Results: The antidepressant effect was prominent at Day 7 postinfusion in the ketamine group but steadily accumulated with the treatment duration from Day 7 to 14 in the iTBS and 10-Hz rTMS groups, regardless of the level of treatment resistance (all p < .01). Low-dose ketamine infusion and iTBS exerted superior effects on suicidal symptoms (HDRS item 3) than the other three groups (p < .001). The antidepressant effect of iTBS/10-Hz rTMS may persist for up to 3 months; however, the antidepressant effect of a single low-dose ketamine infusion did not persist over a month.

Discussion: Both low-dose ketamine infusion and rTMS/TBS must be included in TRD treatment but may be applied in different clinical situations.