Ketamine is a non competitive, N-methylfolate-D-aspartame glutamate receptor antagonist that is approved as an anesthetic agent. Recent studies have shown a rapid onset (2-24 hours post infusion) of antidepressant effect. This effect is short lived, with range of effect form 3-17 days. Studies have found twice weekly dosing to be sufficient over a 4-6  week period. The dose was .5mg/kg. Side effects included headache, dizziness, and nausea as well as acute transient psychotomimetic and dissociative symptoms which resolved within 2 hours. At this time, however studies over efficacy for longer time periods is needed.