Ketamine is known to many people as a party drug (aka Special K), an anesthetic abused for its hallucinogenic and dissociative effects. But ketamine is getting new attention for a more respectable use, as an antidepressant.
While there are many antidepressants already on the market, about one third of patients do not respond to the currently available treatments. For patients who do respond, it may take weeks of use before they feel the full effects of the medication. So clearly, new options for treatment are needed.
Ketamine acts on a different neurochemical pathway than other antidepressants. Ketamine targets glutamate receptors rather than serotonin, norepinephrine, or dopamine like other antidepressants.
It also starts working quickly, within hours of the first dose, and effects can last for several days. But do we want to trade major depression for hallucinations and out-of-body experiences? (I suppose that depends on who you ask.) Ketamine is addictive as well, potentially creating new problems for patients.
Clinics are already opening around the country offering off-label ketamine treatments for depression. With little regulation and few guidelines to assure safety and efficacy, patients are taking unknown risks in order to find relief.
Ketamine is made up of two enantiomers R-ketamine and S-ketamine, molecules that are mirror images of each other. The S enantiomer is reportedly less prone to causing the troublesome side effects like hallucinations.
Clinical trials are evaluating S-ketamine (or esketamine) nasal spray as an option for treatment resistant depression. Results so far are positive for esketamine in combination with an oral antidepressant vs. the oral antidepressant alone.
So we may soon have a new and faster treatment for depression for the many people who have yet to find relief.