Repeated ketamine injections in synergy with antidepressants for treating refractory depression: A case showing 6-month improvement

This case study (2019) explores repeated intravenous (IV) ketamine in synergy with antidepressants to treat refractory depression (TRD). It found that high-dose IV ketamine may stably enhance depressive symptoms and cognitive function in patients with TRD who do not tend to respond to a rapid intravenous dose of standard-dose ketamine.


What is known and objective: Some patients with refractory depression who fail to respond to rapid injection of standard-dose ketamine are injected with high doses, but the safety and efficacy of this practice are unclear.

Case description: A 57-year-old woman with refractory depression whose symptoms did not improve after 20-seconds intravenous injection of 0.5 mg/kg ketamine went into remission following eight, 1-minute intravenous injections of 1 mg/kg ketamine delivered over a 4-week period. By 6-month follow-up, no significant adverse events had occurred and cognitive function had improved.

What is new and conclusion: High-dose intravenous injections of ketamine may stably improve depressive symptoms and cognitive function in patients with refractory depression who do not respond to rapid intravenous injection of standard-dose ketamine. The high-dose treatment appears to be associated with only mild side effects.

Authors: Min Wang, Zhenzhen Xiong, Bin Su, Lan Wang, Zhixiong Li, Yali Yang, Jing Fang & Zhe Li

Study details

Compounds studied

Topics studied
Treatment-Resistant Depression

Study characteristics
Case Study