Its an interesting concept , i've been following near death experiences a bit and the main similarity to a dmt -like experience is this complete loss of body sensation or lack thereof.
I believe there is a universality to our central sense of self that is contained in a very small unit of energy. This unit can detach from the body and travel into other dimensionalities. It also can expand its awareness to absorb , sense and travel in other energy fields.
I think certain overdoses of DMT to the body can trigger some kind of near death mechanism that takes over. But i think there are different kinds of leaving of the body. Some detachments are not a triggered response to stress. Some are a stress response.
The amazing thing to me overall is how natural it feels to experience this out of body feeling.
The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
Arthur C. Clarke
http://vimeo.com/32001208