A commentary to this research has come out (posted by Bancopuma
here).
I believe the scientific commentary mostly agrees with the points we brought up here. Mainly that the DMT surge alone is unlikely to be a bioactive driver of NDE. Also, they point to important surges in many other neurotransmitters, including serotonin which could compete with the increase in DMT for 5HT2 receptor sites.
They also point to the natural activation of kappa opiod receptors (by for example a possible dynorphin increase). In this regard, it is interesting that Aum_Shanti postulated
here a natural opioid agonist acting together with some kind of serotenergic compound (but more 5-MEO-DMT like than DMT) as possibly similar to their personal NDE.
“... (a) psychedelic substance occasionally causes psychotic behaviour in people who have not taken it.”Excerpt from a McKenna talk transcript /
audio.