In looking at the two dark nights, I wondered how they would be viewed from a conventional medical view.
The dark night of the senses, with its experience of being pulled apart, of dying, and possibly of dissasociation, is possibly in the direction of dissasociative disorder or even schizofrenia. (This is a phase of disidentification with the human self and identification as formless awareness.)
The dark night of the soul, with its experience of fall from grace and anything we found comfort in being taken away, is more similar to a deep depression.
Of course, although these two dark night phases can in some cases receive these labels, the reverse is not necessarily true. Of all the cases that could receive these labels, probably very few would have anything to do with the dark nights.