[Ketamine in acute and severe major depressive disorder]

Context: Depression is a frequent, severe and expensive illness. Approximately 20% of depressive episodes are resistant to classic antidepressants. Glutamatergic antagonists, in particular ketamine, established a new, rapid and robust therapeutic approach in resistant depression.

Results: The main results in the literature show a rapid and robust antidepressant effect of ketamine, with infra-anesthesic posology (0.5mg/kg) administered in intravenous way. Positive effects are observed on depressive symptoms, suicidal thoughts, and there is a potential synergic action when used in the induction of anesthesia for electroconvulsive therapy. However, effects only last shortly. Side effects are mostly reversible and of mild intensity, no severe consequences were reported.

Limits: Limits are the lack of power of the included studies, due to small sample sizes, and the scarcity of studies. Misuse of ketamine is an important issue to be taken into account, and few data about ketamine addiction potential and its long-term effects are published at the moment.