Ketamine is considered a treatment for refractory depression. By that I mean that other more conservative measures have been already tried and failed. Treatment with antidepressants, no psychotherapy, psychotherapy have been tried with either no response or sub-optimal response.
Ketamine is administered as a sub-anesthetic dose. Therefore, the medication is administered through an IV as a slow drip at a much lower dosage than you would get for surgical anesthesia. Typically, it is administered for about 40 minutes twice a week. The dosage may be increased slightly after the first 3 sessions for a total of 6 sessions.
Patient’s report significant relief of symptoms typically after 2 weeks. There are many studies that have reported dramatic responses following a single treatment. However, the studies also reported that not all patients responded to the treatment. Also, some patients that did not respond to initial treatment responded to a series of treatments.