I do not think Ketamine should be used in the treatment of severe depression because many dangerous things can happen when someone is under the influence of this drug. It is not the drug itself that kills people. It is the influence that kills people. Under the influence of Ketamine, people have been known to "accidentally" start house fires or get into traffic collisions that ultimately cause death. Additionally, Ketamine features in numbing the whole body, so it is possible that someone can get hurt and then bleed to death without even realizing it, when on Ketamine.
People should refrain from judging Ketamine a miracle treatment for depression. While it is understand those suffering from severe depression would feel that way, more study is needed. Although the drug has been around since the 1960s, it has only recently begun to be used for depression. It has a 75% effectiveness rate, meaning it is not a cure-all.
A miracle treatment would be a treatment for severe depression that has at least a 90% effectiveness rate. A 75% effectiveness rate means that every one in four people will either be negatively affected by the drug or not affected at all. That just does not seem like enough successes in patients to claim it as a "miracle treatment."
Calling Ketamine a miracle treatment is not entirely accurate. Sure it has helped many people, but have these results been compared to placebo effects? Other new drugs tested at the same time? It is still too early to recognize if this treatment is as effective as claimed and not just overhyped.