Horse tranquiliser: the cure for depression?

Ketamine, a structural analogue of phencyclidine, has for years been used as a sedative for procedures and surgery. Treatment-resistant depression (TRD) is depression that has failed to respond to at least two different antidepressants. Recent studies have shown that intravenous ketamine infusions are safe and effective in the short-term treatment of TRD, prompting consideration of its use as an adjunct or alternative to more traditional forms of depression treatment. A nasal spray formulation of ketamine has been approved for use in both the United States and Ireland. Off-label use of ketamine in the United States has expanded to include treatment of anxiety, post-traumatic stress disorder and chronic pain. Long-term efficacy and side effects of maintenance ketamine treatment remain to be studied.