Also depression is in and of itself dangerous. Even avoiding the entire topic of suicide, depression can lead to a variety of self destructive behaviors and poor decisions. Additionally plenty of people suffering from depression will naturally 'self medicate' with drugs that don't actually address the underlying neurological issues that ketamine might, and certainly can cause physical harm.
I think it's somewhat odd that in the 21st century we still aren't comfortable seeing physical and mental illness on the same level. People committing suicide die of an illness in no different a way than people dying of cancer. Yet there is very little in the way of public support of combating suicide the way there is for cancer. There is little debate that opiates (dramatically more risk for abuse) should be used to treat physical pain, and yet people get very nervous about the potential for misuse in a much less risky drug which could provide similar relief to mental anguish.
Yes, some of those that are illegal are certainly physically addictive but at the other end of the spectrum are the likes of LSD and Ketamine, so far off the map that if you could even find someone engaging in addict-like behavior they very likely already have a much larger mental problem.
People often suggests therapy and/or pills that changes you. But they rare suggests exploring external causes, and external solutions.
For example, it may be better to drug bullies rather than victims...
It also fits well with neo-liberal thought:"little concern for externalities", "rational consumer" and this kind of bullshit.
http://www.reddit.com/r/Drugs/comments/h3lbk/ketamine_as_a_p...
And the recreational dose is only a small fraction of the anesthetic dose. And furthermore, you only need to take it once or twice a year for it to be effective. Worrying about brain damage from the antidepressant dose of ketamine is a little like worrying about liver damage from a thimble full of beer.
However, the specific condition I was thinking of is 'Olney's lesions' (overview: http://www.camtriplehelix.com/journal/issue/3/breathing-in-t...). It should be noted that some critical research has been withdrawn in this area, which I had missed, so that raises questions about the accuracy of my original remarks: http://www.erowid.org/chemicals/dxm/dxm_health1.shtml
some guide to doses far below recreational use - looks like 0.15mg per Kg or less might do. I have history of depression in my family - so this is great news.