From my amateurish knowledge, NSI-189 would help to restore the HPA axis if the Glucocorticoid Receptors (GR) are normal i.e. upregulated.
If not then the effects wouldnt be that pronounced like for anyone else.
As said, I´m an amateur, so take this with a grain of salt.
It could also perhaps be the case that by enhancing the Hippocampus, the GR expression would be affected to some extend, but this is just my theory.
On the other hand, the opposite is validated. So an excess of Glucocorticoids ( chronic stress) do damage the Hippocampus.
Does NSI-189 have effects on glucocorticoid receptor density?