Ketamine: stimulating antidepressant treatment?

The appeal of ketamine - in promptly ameliorating depressive symptoms even in those with non-response has led to a dramatic increase in its off-label use. Initial promising results await robust corroboration and key questions remain, particularly concerning its long-term administration. It is, therefore, timely to review the opinions of mood disorder experts worldwide pertaining to ketamine's potential as an option for treating depression and provide a synthesis of perspectives - derived from evidence and clinical experience - and to consider strategies for future investigations.