Endogenous psychedelics (such as DMT and ketamine) are also theorised to be responsible for the near-death experience. Research has found that high doses of DMT has a qualitatively similar flavour to NDEs. Check out my article: https://evan-lhealey.medium.com/do-psychedelics-hold-the-key-to-explaining-near-death-experiences-f9cef3ce0619