Analgesia lamentably concealed mounting depression (7)
I believe the answer is:
malaise
'depression' is the definition.
(I've seen this before)
'analgesia lamentably concealed mounting' is the wordplay.
'concealed' indicates a hidden word.
'mounting' says the letters should be written in reverse (going up in a down clue).
'esialam' is hidden within 'analgesia lamentably'.
'esialam' backwards is 'MALAISE'.
(Other definitions for malaise that I've seen before include "sickness" , "Uneasy feeling" , "Feeling of impending illness" , "General feeling of unease or illness" , "Out-of-sorts feeling" .)