Ketamine was once used mainly as an anesthetic on battlefields and in operating rooms. Now this medication is gaining ground as a promising treatment for some cases of major depression, which is the leading cause of disability worldwide. In the US, recent estimates show 16 million adults had an episode of major depression in the course of a year. Suicide rates rose substantially between 1999 and 2016, increasing by more than 30% in 25 states. Because of its rapid action, ketamine could have a role to play in helping to prevent suicide.
Why is ketamine exciting for treating depression?
If a person responds to ketamine, it can rapidly reduce suicidality (life-threatening thoughts and acts) and relieve other serious symptoms of depression. Ketamine also can be effective for treating depression combined with anxiety.
Other treatments for suicidal thoughts and depression often take weeks or even months to take effect, and some people need to try several medications or approaches to gain relief. This is true for talk therapies, antidepressant medicines, transcranial magnetic stimulation (TMS), and electroconvulsive therapy (ECT), which is currently the most effective treatment for major depression that fails to respond to other therapies.
Are there different types of ketamine?
Two main types of ketamine are used to treat major depression that hasn’t responded to two or more medications (treatment-resistant depression).
- Racemic ketamine, which is most often given as an infusion into the bloodstream. This is sometimes called intravenous, or IV, ketamine. It is a mixture of two mirror-image molecules: “R” and “S” ketamine. While it was approved decades ago as an anesthetic by the FDA, it is used off-label to treat depression.
- Esketamine (Spravato), which the FDA approved in March, is given as a nasal spray. It uses only the “S” molecule.