Ketamine was initially developed in the 1960s as a painkiller and then used as an anesthetic in both humans and veterinary medicine, offering a lower risk of causing heart and respiratory depression than other routinely used anesthetics but due to its potential for hallucinations in recovery immediately post-surgery or post-procedure it is less commonly used in developed countries. Due to its psychedelic properties, it also has become a recreational use substance. In the last 20 years, ketamine has also become a promising treatment for chronic pain and more recently, for treatment-resistant depression. It is thought to work as an antidepressant by rewiring/resetting brain networks involved in depression and creating new brain connections which are different from how SSRIs and other conventional antidepressants are thought to work. It tends to work more quickly, in a matter of hours and days vs. traditional antidepressants take multiple weeks but the results are not permanent after a single dose.
When used as part of a treatment for chronic pain or depression in psychedelic doses, ketamine is infused IV at doses ranging from 0.5 and 1 mg/kg. These doses created a rapid reduction in depression in initial studies from this single session but the results were not sustained after 1 month. This has led to combining single IV dose ketamine sessions with psychotherapy to potentially improve the longer-term response in the brain, something which has been successful in small studies on addiction where it also led to improvements in positive self-image and enhanced feelings of meaning and purpose, which are also important in healing depression.
Black Box Warning & Risks: Ketamine is relatively safe when taken in medical settings after appropriate screening for high-risk individuals who may not be suitable for ketamine therapy. Recreational use of ketamine, especially repeated or regular use, carries greater risks including risk to memory, causing neurodegeneration, addiction potential as well as serious organ damage especially the bladder, kidney, and heart. Large recreational doses may also cause acute risks such as depression of breathing, rapid heart rate, and seizures as well as difficult experiences due to the dissociative nature of the drug.