Efficacy and Safety of a Rapid Intravenous Injection of Ketamine in Treatment-Resistant Major Depression

More Science Research Shows that Ketamine Is Effective

J Clin Psychopharmacol. 2018 Oct 19.


Ketamine has been documented for its rapid antidepressant effects. However, optimal dose and delivery route have not yet been thoroughly investigated. The objectives of this study were to document the safety and test the antidepressant and antisuicidal effects of a single rapid 1-minute injection of ketamine 0.5 mg/kg in treatment-resistant depression.


Ten patients with treatment-resistant depression were included in an open, noncontrolled 4-week study and received a rapid intravenous dose of ketamine 0.5 mg/kg. Main outcome measure was the Montgomery-Åsberg Depression Rating Scale and suicidality was assessed using the Scale for Suicide Ideation.


Rapid injection of ketamine elicited transient increase of blood pressure and altered states of consciousness in all patients and mild psychotomimetic effects in 4 patients, which all resolved without any intervention. Decrease of depression severity was observed from 40-minute postinjection until day 15. Eight patients became responders within 1 day and all were nonresponders after 4 weeks. The decrease of suicidal ideation was significant until day 7. Analysis indicated that higher severity of depression and anxiety at baseline predicted a larger Montgomery-Åsberg Depression Rating Scale decrease after 4 weeks.


This study suggests that in well-controlled medical settings with adequate monitoring, a single rapid 1-minute injection of ketamine 0.5 mg/kg can be well tolerated and is efficacious in rapidly reducing depression symptoms and suicidal thoughts in outpatients with treatment-resistant depression. These findings are relevant to the practice of general clinical psychiatry and emergency departments were ketamine can have a place in acute management of treatment-resistant depression. Larger studies are necessary to confirm these results.