• Ketamine has been shown to rapidly improve depression and has been promoted in young adults.

• Ketamine in older population has not been widely studied.  

• Single infusion of ketamine could improve depressive symptoms in elderly patients. 

• Administration of low dosages (0.5 mg/kg) of Ketamine was associated with good tolerability profile in elderly patients.

• This work provides useful information regarding novelty evidence for at least a short-term effect of ketamine on depressive symptom severity in a minor-sedative surgical context.