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, where it also led to improvements in positive self-image and enhanced feelings of meaning and purpose, which are also important in healing depression.
Intranasal ketamine, is now a USA FDA-approved drug with breakthrough drug status for treatment-resistant depression, to be used in combination with an antidepressant oral pill medication. It comes in a form called Esketamine, which has a slightly different molecular makeup and is taken under supervision in a healthcare setting via a nasal spray. It is taken 2x a week, then once a week, and then every two weeks in the maintenance phase under doctor monitoring. This form of ketamine does not usually cause hallucinations and after inhaling the medication, you sit in a comfortable reclined position for observation and checking blood pressure for a minimum of two hours before you can go home. Hence, it is not as easy as taking a pill at home but does not require as long a session or monitoring as IV ketamine therapeutic doses are used and are less invasive.
Black Box Warning & Risks: Ketamine is relatively safe when taken in medical settings and after the appropriate screening. 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.