Efficacy of Ketamine in bipolar depression: focus on anhedonia.

: Bipolar depression (BD) is among the most severe psychiatric disorders. A significant number of patients do not achieve an entirely symptom-free state and experience residual sub-syndromal depression. Most of the treatment options approved for bipolar depression give no rapid symptom improvement. Ketamine is an anaesthetic medication that acts as an antagonist of the NMDA receptor and has antidepressant potential. Due to its unique way of action, ketamine seems to be crucial for the treatment of anhedonia. This review paper aims to provide an overview of the efficacy of ketamine infusions in bipolar depression with a focus on anhedonia Literature suggests that intravenous ketamine 0.5 mg/kg over 40 min weekly could be useful in the treatment of bipolar depression with prominent anhedonia, but there is still a small number of studies that examine the efficacy of ketamine infusions in BD. In conclusion, ketamine should be considered as a valuable treatment option for patients with BD and anhedonia.