Ketamine's short, medium, and long-term mechanisms lead to changes in neurochemistry and neural circuit wiring, enabling relief from depression.

“it's very likely that ketamine is acting by at least two and probably three different mechanisms in order to provide relief from depression one of those mechanisms induces relief from depression very quickly and seems to be associated with that euphoric dissociative dreamlike state that one experiences when they are under the influence of ketamine the second mechanism seems to provide relief from depression in the days and weeks that follow the ketamine treatment and there also appears to be a third mechanism by which ketamine can induce longlasting changes in the nervous system”