Over the past twenty years, ketamine infusions have been extensively studied for the treatment of medication-resistant depression. Psychiatrists have performed the vast majority of studies, so only very low doses of ketamine have typically been used (0.5 mg/kg given over 40 – 60 minutes). Even at these low doses, we can expect approximately 60 – 70% of patients to find relief. However, within 3 weeks of completing the initial course of 6 low-dose infusions, half to three-fourths of patients have return of their depression.
Fortunately, anesthesiologists can administer much higher doses of ketamine (as much as 4 – 5 times higher), and some patients who do not respond at the lower dose will, fortunately, find relief with a more aggressive dosing regimen. In addition, the higher doses that we give allow a considerably longer period of relief, and patients can thereby extend the time period between “maintenance” infusions. This benefits patient both financially as well as being far less disruptive to their lives.