Ketamine is a medication mainly used for starting and maintaining anesthesia. It is an NMDA receptor antagonist and works by disrupting the communication between neurons in the brain. Ketamine can be injected into a muscle, veins, or under the skin. When used as an anesthetic, it causes loss of consciousness within 30 seconds to 1 minute. The effects of ketamine last for about 25 to 35 minutes.
Ketamine has a number of off-label uses, including treatment of depression, anxiety, and chronic pain. In recent years, ketamine has also been studied as a possible treatment for post-traumatic stress disorder (PTSD).
A small number of studies have found that ketamine may be helpful in treating depression, particularly treatment-resistant depression. Ketamine appears to work differently than other antidepressants by targeting a different neurotransmitter system. It is thought to increase levels of norepinephrine and glutamate, which play key roles in mood regulation.
A few studies have also looked at using ketamine to treat anxiety disorders, with mixed results. One study found that a single dose of ketamine was effective in reducing symptoms of social anxiety disorder, while another found no significant improvement in symptoms of generalized anxiety disorder.
Ketamine has also been studied as a possible treatment for chronic pain. A review of studies found that ketamine was effective in reducing chronic pain in adults, although the quality of evidence was low.